[ 3 / biz / cgl / ck / diy / fa / ic / jp / lit / sci / vr / vt ] [ index / top / reports ] [ become a patron ] [ status ]
2023-11: Warosu is now out of extended maintenance.

/diy/ - Do It Yourself


View post   

File: 84 KB, 620x425, 1504299138093.jpg [View same] [iqdb] [saucenao] [google]
1247660 No.1247660 [Reply] [Original]

bump limit reached on old thread >>1242891

https://www.wiki.printf.pl/index.php?title=Pasta (fresh)

>I'm new to electronics, where to get started?
There are several good books and YouTube channels that are commonly recommended for beginners and those wanting to learn more, many with advanced techniques. The best way to get involved in electronics is just to make stuff. Don't be afraid to get your hands dirty.

>What books are there?
Beginner:
Getting Started in Electronics Forrest Mims III
Make: Electronics Charles Platt
How to Diagnose Fix Everything Electronic Michael Jay Greier

Intermediate:
All New Electronics Self-Teaching Guide: Kybett, Boysen
Practical Electronics for Inventors: Paul Scherz and Simon Monk

Advanced:
The Art of Electronics by Paul Horowitz and Winfield Hill

>What YouTube channels are there?
mjlorton
paceworldwide
eevblog
EcProjects
greatscottlab
AfroTechMods
Photonvids
sdgelectronics
TheSignalPathBlog

>What websites feature electronics projects or ideas?
http://adafruit.com
http://instructables.com/tag/type-id/category-technology/
http://makezine.com/category/electronics/

>Where do I get components and lab equipment from?
ladyada.net/library/procure/hobbyist.html
Search the web for "hobbyist electronics sources" to find plenty.
In the US and elsewhere, mouser.com, digikey.com, arrow.com, newark.com are full-line distributors that entertain small orders.

>What circuit sim software do you use?
This mostly comes down to personal preference. These are the most common ones though:
NI Multisim
LTSpice
CircuitLab
iCircuit for Macs
CircuitJS (quick, dirty, interactive)

>What software should I use to layout boards?
Circuit Wizard
ExpressPCB
EAGLE
KiCad

>Q1. Lithium batteries
Will explode if you abuse them. Read and understand all relevant datasheets and be prepared for catastrophe. See
batteryuniversity.com/learn/
>Q2. My circuit doesn't work. Halp?
Check wiring, soldering, part pinouts, and board artwork if applicable, then post schematic.

>> No.1247665
File: 43 KB, 500x483, 1494109866186.jpg [View same] [iqdb] [saucenao] [google]
1247665

Today's chip, in honor of digits, is the charge pump. Because why not.

>> No.1247680
File: 29 KB, 536x466, Screen Shot 2017-09-21 at 9.29.45 PM.png [View same] [iqdb] [saucenao] [google]
1247680

>>1247655
>Probably because your output impedance is asymmetrical.
I'm modelling a sawtooth generator with 3 RC filters, no output impedance about it.

>LC circuit
Because tuning one at these high frequencies would be somewhat tough, not to mention requiring incredibly small part values. I figured using another crystal would be not only equivalent to this but also much more accurate, and not cost much more at all.

>> No.1247683
File: 79 KB, 628x720, Screen Shot 2017-09-21 at 9.34.19 PM.png [View same] [iqdb] [saucenao] [google]
1247683

>>1247680
Sawtooth.

>> No.1247687

>>1247680
Crystals aren't really meant to handle much power, usually on the order of a microwatt.
>incredibly small part values
Just did the math, and, well, shit. What's your actual oscillator circuit look like? I'd be surprised if there were no sine wave available.

>> No.1247722
File: 3.85 MB, 3072x2803, 20170921_140143.jpg [View same] [iqdb] [saucenao] [google]
1247722

So I'm connecting:

Electrical grid -> circuit breaker (pic) -> transformers

On which of the four inputs do I put my phase and neutral (electrical grid -> circuit breaker).

thanks

>> No.1247728

>>1247722
are you sure you want to switch neutral too? if so then e.g. bottom left L in, top left L out (switched) and bottom right N in, top right N out (switched). diagram says direction doesn't matter, top in bottom out should work as well. or so i think. wait for some certified electrician to chime in..

>> No.1247730

>>1247665
What is that and how does it work?

>> No.1247736

>>1247538
>If you're using the Pi3, you'd want to make sure you have at least a 2.1, if not 3A adapter. And actually buy an official one, Pi3 is very sensitive to voltage drips. Mine never crashed, but I've had it with a solid low voltage warning despite a 2.1A adapter that worked fine for everything else.

I'm using the zero w. The step down converter is rated to be 3A. The only peripheral connected to the pi is the RPI camera.

>> No.1247742

>>1247730
It's a simple switch mode power supply using one external capacitor that provides the negative of the input voltage. Inside is an oscillator, and a set of MOSFETs that switches the external capacitor between being connected from Vin to ground, charging the cap and from ground to Vout.

Very useful for things like generating a negative supply for amplifier/filter circuits if you only have a positive supply.

Similar circuits can also be used to double the input voltage, or with multiple caps a wide range of different ratios.

>> No.1247751

>>1247742
Neat, thanks anon.

>> No.1247752

>>1247687
I'd amplify the signal after it comes out of the crystal, not try to drive the load directly from it. The RF amplifier(s) aren't a problem. I haven't sorted out what the circuit will be, but if I can simply feed a low amplitude buffered filtered sawtooth into the crystal and get a near-perfect sinusoid out of it that would be great. I guess I'll play around with modelling a crystal as an LC network in Spice.

>> No.1247838

what kind of solder does /diy/ use?
ive run out of my generic .5mm 60/40.
Is multi core worth it?
are people still using 60/40 in the (((current year))) or did everyone switch to superior Sn62Pb36Ag2 / Sn63Pb37

>> No.1247840

Just started at uni doing a course in robotics and electrical engineering.
Currently know fuck all about electronics other than basic secondary school stuff so I bought an arduino starter kit to play about on at home and supplement my studies.
Beyond the toy projects in the starter book do you guys know about any good beginner level projects or guides to help give you a grasp on basic circuit building for a non-extortionate amount of money?

>> No.1247844

>>1247840
where i came from they made everyone design and build a simple latching switch out of a pushbutton and 3 ordinary double no/nc relays activating on edge
>hardmode
>only use pen/paper
>dont google it

>> No.1247847

>>1247840
if you want to learn ELECTRONICS then microcontroller/embedded/arduio is literally the worst place you can start.
get the basics down first: potential divider, transistors, multivibrators, 555s, amplifiers, opamps, radio covers pretty much the basics of analog.

>> No.1247851

>>1247838
.2mm masterrace

>> No.1247852

>>1247847
those days are long gone
all of those things are now replaced by an arduino or a pi

>> No.1247889

>>1247838
Ag only makes sense if you solder silver-coated wires, like for high-Q filters and resonators. I use Sn60Pb39Cu1 1mm and Sn60Pb38Cu2 0.7mm, both fluxcore. 2x500g, will probably last forever. After that comes the lead-free era of horror: Sn95Sb5 or Sn95Ag4Cu1. No more shiny joints.

>> No.1247906

>>1247889
after looking at the 200 entry wikipedia table im giving Sn62Pb37Cu1 a shot, "Eutectic" has grabbed my attention

>> No.1247945

>>1247906
>Sn62Pb37Cu1
Difficult, last supplier seems to be marmot.cz
The future is lead-free :(

>> No.1247982
File: 4 KB, 448x283, overtone-response-quartz-crystal.png [View same] [iqdb] [saucenao] [google]
1247982

>>1247752
>modelling a crystal as an LC network in Spice
Good luck. There are no GHz crystals.

>> No.1247992

>>1247982
I'll model it as a 5th or 7th overtone, because wikipedia. I think LC circuits can be run like that.

>> No.1247997

>>1247752
How the fuck do you presume to generate a sharp 1.2GHz sawtooth waveform? I think you need to put down the LTspice and lern2radio.

>>1247838
1.5mm SAC305.
Multicore is great solder.

>>1247840
Read the OP

>>1247852
Low effort bait

>> No.1248004
File: 106 KB, 633x599, One-port-SAW-resonator-frequency-response.png [View same] [iqdb] [saucenao] [google]
1248004

>>1247992
7th's are 80-180 MHz
http://www.calcrystal.com/crystals.html
GHz is always SAW

>> No.1248010

>>1247840
build an optical tachometer

>> No.1248062

regarding electronics as a business:
is it even necessary to know electronics to build and sell hardware (say, embedded stuff) these days? with the cheap, small, high-powered computers with lots of peripherals, standardized comms and stuff..
don't get me wrong, I know that you can save a lot of money if you use the right hardware, but still, shit's really cheap these days.

>> No.1248065

>>1248062
what is hard is to make it cheaper than the chinese crap
if you make it very customized it could work

>> No.1248090

>>1248062
>can i pretend the physical layer doesn't exist
You and every other Western philosopher, I swear.
Most people in the position of professional ardweenie retain a consulting engineer to handle the electronic design portion of the project and ensure that the appropriate regulatory standards such as unintentional RF radiation limits are met.

>> No.1248092

>>1248065
but why would you make it cheaper than the chinese crap? just add "value"... look at apple, for example. rarely they add something new, they don't even create any of the features in their phones (usually other companies invent the tech, they just apply it) and yet are one of the most profitable consumer electronics companies

also, look at kickstarter, some of the stuff they sell are pure marketing..

>>1248090
true, but what if I simply repurpose existing stuff? say, using a wifi router as a local webserver for some specialized use?

>> No.1248093

>>1248092
It's certainly happened. But that isn't electronics, just web development and maybe system administration. Maybe you'll find the two dozen grandmas or technologically helpless doctors who need whatever that thing is and are willing to pay for you to continue to upgrade gentoo every time some new security hole comes round.

>> No.1248097

>>1248092
>look at apple
apple sells based on brand cult, this is not the place to marketing, we discuss electronics here

>> No.1248105

>>1248092
>>1248093
Also, when the vendor decides to change up the hardware radically with a new rev, or enhance their anti-tampering code, or simply discontinues the model on which your system is based. Radio code or component modifications require recertification by the applicable communications authority. And so on. The WRT54GL is the exception, not the norm.

>>1248092
>look at apple, for example. rarely they add something new, they don't even create any of the features in their phones
They most certainly do design the circuitry that goes into those things and do work with vendors to help develop the components they buy. Surely you don't think they buy chinkshit arduino modules off ebay, or grab an all-in-one reference design from their SoC vendor, that is, themselves? You really do have to know what you're doing when you need more exquisite performance than eventually turning a GPIO on or off after a command has been received.

>> No.1248114

I'm reasonably profficient with VHDL now thanks to uni and my work placements, but I'd like to get experience with verilog too, any recs for decent affordable FPGA dev boards?

>> No.1248118

>>1248093
but you are selling hardware... and software, too, just like most electronics vendors do. these days, what devices does NOT use linux or some other popular embedded OS?

>>1248097
true, but the topic was
>selling electronics

>>1248105
>Also, when the vendor decides to change up the hardware radically with a new rev, or enhance their anti-tampering code, or simply discontinues the model on which your system is based. Radio code or component modifications require recertification by the applicable communications authority. And so on. The WRT54GL is the exception, not the norm.
most home & office routers use linux these days. some vendors even distribute openwrt.

>>1248105
>They most certainly do design the circuitry that goes into those things and do work with vendors to help develop the components they buy. Surely you don't think they buy chinkshit arduino modules off ebay, or grab an all-in-one reference design from their SoC vendor, that is, themselves?
I mean, they do, of course, but people usually think they invent anything.


but, true, you need specialized knowledge if you go big, of course... my point is, you don't *always* need that, at least to start.

>> No.1248143

>>1248004
>GHz is always SAW
Is that because of the other overtones adding? I guess I'll just chain 6 or so low pass filters together. With a high gain amp somewhere in there and a high power amp at the end. Anyone have experience with very high frequency resonators/circuits? I know I have to watch out for parasitic inductance and capacitance, so I'll have to watch what voltage rail I use for what. Maybe even use an isolation transformer if I can if that will help.

>> No.1248151

>>1248114
No-name Altera core-boards are pretty cheap on AliExpress. Except for high-speed stuff like DDR RAM, it's almost always cheaper to just run fly leads to yuor chosen chinkshit Arduino modules than to buy the official comprehensive dev board with a bunch of 7-segment displays on them. What sorts of projects were you looking to do with them?

>>1248118
>most home & office routers use linux these days. some vendors even distribute openwrt.
That doesn't mean that you can make any use of them, necessarily.
>I mean, they do, of course, but people usually think they invent anything.
Isn't that basic hardware engineering exactly the part of the process you're trying to avoid here? If you don't even have an idea of a particular project you want to do, then the only answer worth giving is "maybe, maybe not".

>> No.1248158

>>1248151
>Isn't that basic hardware engineering exactly the part of the process you're trying to avoid here?
yep, because I don't have the specialized knowledge (which, btw, is really expensive)... but I have the tools, and the hardware, so what's the problem? if I had my own hw project and ever got enough money to hire someone to do the hard technical work for me (the electronics part I mean), then I'd do it

>> No.1248162

>>1248158
What you are describing appears to be called "prototyping". Sure, we all do this. Have at it and (hopefully) learn a few things in the process.

>> No.1248170
File: 25 KB, 600x600, received_10207560475088428.jpg [View same] [iqdb] [saucenao] [google]
1248170

I am looking to try and figure out how hard a paintball is hitting an object. I have been looking into force sensors like the one in my pic, but most seem like they are too slow or not good for this application. Is there a better type of sensor or method of testing for this? We have a chronometer, but we need to know how hard it hits and not how fast it goes, and given how we all use different paintballs, we figured calculating from mass would be too much effort for doing it for every shot made. Any ideas or advice on parts?

>> No.1248176

I want to build a drone, on the web people recommend a D10N05 mosfet to drive the motors, but I cannot find the little fucker anywhere
Maybe an alternative?
The motors draw up to 3 A, and it will run from a 3.7v battery, so it needs low gate voltage

>> No.1248178

>>1248170
what are the units you want to measure in? Even with a shitty device/setup you can always calibrate out the errors with a little extra work. In your case you can take a weight with an exactly known mass and drop it from various heights onto the impact sensor, then measure the response and generate a calibration curve that tells you what amount of "signal" coming out of the device corresponds to what amount of force or impulse you dropped on it.

>> No.1248180

>>1248178
Ah shit that is a good idea. And any units at this point, we just couldn't think of how to calibrate the smaller issues out so we wanted results of any type at this point.

>> No.1248181

>>1248170
Microphones or piezo elements might be worth trying.

>>1248176
D13N10L maybe, if you don't mind a relatively high Rds(on)? Vgs(on) is the key parameter you want to optimize for, followed by Rds(on). Check out your favorite supplier's parametric selection page, for example, Digi-Key's here:
https://www.digikey.com/products/en/discrete-semiconductor-products/transistors-fets-mosfets-single/278

>> No.1248182

>>1248151
nothing impressive to be honest, i'm just exploring syntax differences really so I don't need more than a few LED peripherals to blink and tell me whether or not I've royally fucked something

bit overkill for a dev board probably but I'm inexperienced in the hobbyist side of this discipline so wasn't sure whether there were any standard recommended boards for people poking around at RTL

>> No.1248191

>>1248182
ah, on AliExpress you could pick up a Cyclone II board with an assortment of hard bits for about 15 burgers and a clone USB Blaster JTAG pod for about 5 burgers. LEDs and switches are a burger or two for a small bag.
If you were looking for a Xilinx setup instead, Digilent's boards are commonly recommended for beginners, but they're usually equipped generously with peripherals, include a USB programmer on board, and aren't priced as low as chinkshit.

>> No.1248202

>>1248191
If I'm going out of my way to learn verilog I probably should be exposing myself to new FPGA manufacturers and their tools whilst I'm at it, Cyclone II here I come

>> No.1248210

>>1247838
I bought some "expired" shit, lead-free, 1lb for $20. It's not high-temp, and it gets the job done for me.

Tin 96.5, Silver 3, copper .5

>> No.1248229

>>1248202
The big two are Xilinx and Altera. Lattice and Microsemi are niche players in the programmable logic space. Atmel's basically out of the game.
fwiw you can also get chinkshit Xilinx boards and JTAG pods on aliexpress, but they're significantly more expensive and iirc the latest IDE doesn't support the cheaper, older chips anymore.
>tools
Their IDEs are pretty nearly the same as any other IDE, and the development flow isn't much different between them.

>>1248210
>SAC305 masterrace
It's high-temp. What diameter?

>> No.1248278

>>1248170
if you want to find out how hard it's hitting then you want to measure kinetic energy transferred, not force. You could build a swinging panel and with a high speed camera measure how much it swings on impact, put a scale behind it based on some calculations on how much energy it would take to raise the panel to that height and then you've avoided the problem of hitting electronic components with paintballs altogether.

>> No.1248300

>>1248278
in fact, avoid the high speed camera and go full mechanical with a pointer that is pushed by the swinging panel to maximum of its vertical travel and then stays there as the panel returns to vertical.

>> No.1248320

>>1248170
If speed is the issue, add a mechanical low-pass filter. I.e. heavy plate -> spring -> load cell.

The area under the curve will be unchanged, but the curve will be wider and lower (less force for more time).

>> No.1248403

>>1247997
For a good 90% of little projects, arduino/pi works perfectly, don't kid yourself.

>> No.1248413

Before the lolduino electronics did not exist.

>> No.1248414

Can A2F500 do LVCMOS 1v8 on bank 4 when the MAC is disabled?

>> No.1248438

The +12V input pins plastic housing for my RAMPs board hotend was melted to oblivion. Basicly disabling the hotend too. Started working once I strippwd it and screwd it back. Was the melting caused by the hotend or by the board? I know its impoasible to tell for sure but what do you suspect.

>> No.1248532
File: 29 KB, 1000x1800, 1505383421142.png [View same] [iqdb] [saucenao] [google]
1248532

Imagine this must have slid a lot. Have a bump.

>> No.1248583

>>1247660
dunno if this is a good thread to ask or not (I rarely even lurk /diy/ forgive me--I lost interest after the guy who wanted a half ton of fake crab meat disappeared years ago)

Which Baofengs are, in fact, decent? I just got my Technician. I was considering a Yaesu VX-6, which I know are good, but fucking expensive and I don't want to overbuy for my first toy in a new hobby

>> No.1248592

>>1248583
Try chink shit general on /g/ bud, the paid shills can let you know which to order.

>> No.1248596

>>1248592
Thanks, friend.

I go to /g/ even less frequently.

Also, what DID happen to imitation crab meat dude? Does anyone know?

>> No.1248604
File: 29 KB, 270x247, BF-F8HP.jpg [View same] [iqdb] [saucenao] [google]
1248604

>>1248583
No first hand experience
Latest UV-5R model seems to be BF-F8HP
baofengtech.com/baofeng-radio
Discontinued radios are cheap now
Amazon ebay whatever

>> No.1248655

>>1248583
>>1248604
Confirming UV-5R is a good radio. Not a great radio mind you, just good. They are great first time radios for freshly licensed hams. You can find them as cheap as $25. Downside is, its a $25 radio, and expect it to perform as much. I've found they have a life expectancy of about a year before they start falling apart. If you get it, get yourself a different antenna than stock. Its shit. All things considered its great for what it is. And though its frequently mentioned how voice is on the quiet end, it will get you into repeaters just as good as more expensive radios.

>> No.1248767

>>1248403
"With sufficient thrust, pigs fly just fine."
There are values of "little" and "perfectly" for which your statement is true, no doubt. People choosing and doing projects with attention to lolduino/pi's limits will no doubt be satisfied.
Trouble is, they don't learn microcontrollers or electronics, they learn arduino/pi and are not in the best position to generalize their abilities to other projects or to move beyond arduino's limits by, say, bit-banging SPI. They learn nothing about how to even approach the other 10% or of anything bigger, which as often as not is simply the composition of broader building blocks in ways lolduinoists did not anticipate. They then resort to massive buyfaggotry or having other people work their design out for them or posting questions like "is this possible?" rather than doing their homework and asking "is this approach sane?"
By structuring their learning around connecting stuff to the little black box and programming it with the magical incantations to do stuff, they learn nothing about how to do it when they don't have enough magic inside the little magical black box.
>resistive dividers and op amps replaced by microcontrollers
You're just shitposting now.

>> No.1248778

>>1248767
>butthurt oldfag is butthurt

>> No.1248838
File: 12 KB, 241x364, Capture.png [View same] [iqdb] [saucenao] [google]
1248838

I need to choose some values for Rc so that the transistor is in saturation mode and some values that put it into active mode

Vcc is 15V. Vce(sat) is 0.5V. Vbe is 0.7V. The beta value of the transistor is 150

(15V - 0.5) / 2mA = 7.25k ohms

So if I choose resistors greaters than 7.25k ohms that should put it into saturation mode and smallers ones will put it into active mode

Is everything I said correct?

>> No.1248846
File: 82 KB, 799x450, IMG_20170825_192241587-L.jpg [View same] [iqdb] [saucenao] [google]
1248846

>>1248604
Basically what >>1248655 said.
But I wouldn't even call them "good" radios. You get a lot of radio for the money, sure, but they're still pretty shitty radios.
Legal issues aside...
>get your damn ham license, it's cheap/easy.
My 5-watt baomeme meters a little over 3.5 on a calibrated power meter.
The receivers are pretty terrible. A better antenna helps, but the receiver still isn't very selective.

But for $30, yeah, it's decent if radio's a hobby you're interested in.
If you just want to talk with friends when you're innawoods, go with a sporting-goods store frs/gmrs radio. Those will work better, and they're a hell of a lot easier to use.

>using Baofeng as a unit of currency
>The cheap Motorola speaker-mic is about B1.5
>the nicer speaker-mic is about B2.5
>those radios are about B35/ea

>> No.1248848

>>1248838
It's not wrong, but it's somewhat ambiguous.
If you can guarantee 2mA collector current, it is true.

>> No.1248849

>>1248848
Rb is connected to a potentiometer so i think that should work

>> No.1248878

>>1248849
What's the practical point of all this? Ohm's law exercise?

>> No.1248881

>>1248767
>c
>magical incantations

>> No.1248882

>>1248838
Assuming Rb is also connected to Vcc, and an otherwise ideal transistor, Rb/Rc > beta will cause the transistor to saturate.

>>1248881
>hurr durr ADCs appear like magic on any pin
>hurr durr op amps can be instantiated in software
Just stop, admit that you're a terminal bit weenie, and understand that there are things you will never understand.

>> No.1248896

>>1247847
>>1247852
>>1247997
>>1248403
>>1248767
>>1248881
>>1248882
I'm really enjoying this argument guys, but my comment was about electronics in the context of robotics. with robotics being the primary focus of my course. So i'm pretty sure that micro controllers and coding are going to be a big part of my work for the next few decades.

>> No.1248897

>>1248896
You're still not gonna have much luck driving motors with a naked microcontroller.
You could ask on arduino.cc, they might have some ideas that are more up your alley.

>> No.1248927

>>1248878
This is part of my lab. They're teaching us to design analog circuits and in this part we have to pick resistance values to match to criteria.

>> No.1248932
File: 1.25 MB, 3120x3120, IMG_20170922_155109.jpg [View same] [iqdb] [saucenao] [google]
1248932

I built a dual flashing led strip board (12v) with a 555 timer, but the strips aren't as bright as they are with the straight 12v connected. As a guide, I used this video: https://youtu.be/y2UYPpNQRJg what can I do to make the strips light up like they should? Thanks, you wise men.

>> No.1248952

Yesterday I changed the light fixture in my room. After unscrewing the old one, I used a phase tester screwdriver on each of the three leads sticking out of the ceiling, and two of them showed a voltage (the ground didn't, naturally).
Is this normal? It surprised me because I expected only one to light up. My dad who studied EE back in the day said maybe both wires were phases, but i don't believe that because i'm pretty sure every house only gets wired to one phase from the grid, and the light switch was off anyway. My tentative explanation was residual capacitance between the two conducting wires, which would then simply be a phase and the neutral.
When we hooked up the wires to the new lamp, it slightly flickered on a little bit before turning off completely.
Thoughts?

This is in Belgium btw.

>> No.1248954

>>1248932
what leds do you have connected? the 555 timer (or any other ic like that) has a non-zero output resistance so the more current you draw the less voltage you get at its output.

http://www.ti.com/lit/ds/symlink/lm555.pdf
ctrl+f "Output Voltage Drop"

>> No.1248976

>>1248932
What is the current your LED strips draw at 12V? Are they separate or is there a common rail?

>> No.1248977

>>1248954
I have 60 12v 2835s per side, alternating. I'm feeding it. I had a "12v" 1A supply but I burned a timer by plugging the power in backwards, and finding later than the supply was actually delivering 17v. So I used buck converter, and it is now 12v, but the dimness is the same.

>> No.1248979

>>1248976
Common rail, just a 12v+ and gnd that powers the entire strip. I didn't test the current draw, since connecting them directly made them nice and bright.

>> No.1248994
File: 43 KB, 249x230, image1.png [View same] [iqdb] [saucenao] [google]
1248994

>>1248977
>dimness is the same
Of course it is.
>>1248979
>nice and bright
At 12V. Diagram needed, info is too fuzzy. The LEDs in the image have NO common rail.

>> No.1248995

>>1248952
When you say phase detecting screwdriver it might just be bullshit, depends on the type, if its an actual screwdriver you have to touch then its garbage, if its a proper non contact voltage probe then its more reliable.

American houses typically run on a phase via a central tapped transformer giving you essentially two phases w.r.t ' ground'

Residual capacitance be careful, it won't be electricity left over from last time the light was on, it will be electricity coupled by ac induction from other live wires in the house, commonly known as parasitic capacitance.

Typically it's tiny tiny tiny amounts of current available but high efficiency lamps e.g. Led with certain capacitive power converters inside are able to store this tiny amount of energy until enough to turn the led on, it will flash using the charge up then start storing again, giving brief flashes with a long time between, maybe minutes maybe hours.

Of course your house might just be fucked

>> No.1248996
File: 6 KB, 300x385, B.png [View same] [iqdb] [saucenao] [google]
1248996

>>1248927
Okay, good start. Can you experiment?

>> No.1248997
File: 40 KB, 630x564, Dual-LED-Flashing-Circuit.png [View same] [iqdb] [saucenao] [google]
1248997

>>1248994
This is the diagram the video supplied. All I did was replace the single LEDs with the strips.

>> No.1248998

>>1248994
drive the leds with a transistor

>> No.1249005

>>1248896
If you think you can do digital without learning analog then I'm sorry but you are in for a big surprise. Digital is digital in name only.
If you want to connect a few hobby servos to arduino shield then you don't need to learn anything.
Look e.g. at quadcopters, I know several people who wind their own motors ffs.
The fact its robotics has nothing to do with anything, you take it as far as you are willing to go, but I don't know anyone who ever complained that they knew too much about their supposed hobby....

>> No.1249006
File: 208 KB, 1920x1080, 20170728142856_1.jpg [View same] [iqdb] [saucenao] [google]
1249006

Does anyone here know a good book about vacuum tubes? Im a beginner in electronics and i plan on restoring some old equipment. my first project was to repair a tube radio, but sadly the audio transformer was shorting out. I think im gonna repair a vacuum tube signal generato next.

>> No.1249011

>>1248998
>with a transistor
or two, no problem. But you need the current or the power of the two strips.

>> No.1249015

>>1248995
>if its an actual screwdriver you have to touch then its garbage
it's the kind you have to touch.

>Residual capacitance be careful, it won't be electricity left over from last time the light was on
This is what I was thinking, yes. If it was capacitance from other wires then wouldn't it have kept flickering? Instead it just did it a few times then died out.
Anyway, thanks for your input

>> No.1249017

>>1248952
>the light switch was off anyway
Switch it ON and repeat the phase testing. The one that is brighter is the (switched) phase.

>> No.1249025

>>1249006
Wikipedia about tubes in general, data sheets of the tubes used, circuit diagram of the signal generator. Old diagrams often show testable voltages which facilitates diagnosis.

>> No.1249029

>>1249011
I'm not home right now, but I'll try to get a current draw measurement later tonight. As for the transistors, include them in the circuit? Connect the collector to the positive coming from the timer and emitter to 12+ on the led strip, then gnd from the strip to gnd on the board?

>> No.1249034
File: 52 KB, 640x400, nigger.png [View same] [iqdb] [saucenao] [google]
1249034

>>1249029

>> No.1249042

>>1249029
Measure at 12V and be sure to use the 10 Amps range on your meter. You will probably need something bigger than small signal transistors (the 100mA kind).

>> No.1249043

>>1249029

if you have 60 LEDs; assuming 20mA per, it means they need 1.2A total which is about 6 times what a 555 can put out. so a transistor is needed, but the nig here >>1249034 is just as confused as you, so dont pay too much attention. e.g. he has 10K on the base, which would limit base current to 1.2mA, so a typical transistor with a gain of 100 would only be able to put out 120mA, which is 10x short of what you need.

replace the transistor with a power darlington (or make your own darlington using 2 NPN transistors, the second one being a power transistor) eliminate the 120ohm resistor,and that'll work. some MOSFETs would also work, but they are too voodoo for yooou.

>> No.1249074
File: 1.13 MB, 1920x886, 2017-09-23 17.00.59.jpg [View same] [iqdb] [saucenao] [google]
1249074

>well gee, this pin is named VUSB and is right next to the D+ and D- pins
>it must be where you put the 5v
>wait why isn't my circuit working
alas, it was too late for the mcp2221a

>> No.1249092
File: 3.48 MB, 1440x2560, wp_ss_20170923_0001.png [View same] [iqdb] [saucenao] [google]
1249092

Are there any readily available replacements for pot grease?

Oscilloscope pot anon is back after three weeks and there was a blob of (oxidized?) grease stuck to the wiper

>> No.1249094

>>1249092
>ima be smart and screenshot this 7meg .jpg picture
>screenshot is .png
Fuckit.

>> No.1249102
File: 8 KB, 408x175, bipmos.png [View same] [iqdb] [saucenao] [google]
1249102

>>1249043
The 555 can supply 50mA (sink better than source, more is not healthy) which is enough to saturate a transistor (e.g. BD435/436) to less than 0.2V at about 1A. Darlington configuration (e.g. TIP110/115) drops about 0.8V.

>> No.1249103

>>1249043

I'll give it a try. I don't have any mosfets anyway. Is there another timer that would let me put that current though? Or maybe an astable multivibrator with tip31c transistors would be a better board to build? I ask because I have a shitload of those. Thanks for the help, btw.

>> No.1249112

>>1249103
You can use 2x TIP31 if you have another small PNP transistor like BC557 or 2N3906.

>> No.1249118

>>1249112
I have a few bc945 transistors I scavenged from an old LCD Tv. Would those do?

>> No.1249120

>>1249118
Did you look at the datasheet?

>> No.1249126

>>1249120
Yes, but other than dc current gain, I'm not sure of what I'm looking for.

>> No.1249129

just tried soldering for the first time. Does everyone absolutely suck the first time or should I just off myself now?

>> No.1249137

>>1249129
You probably didn't use enough flux.

>> No.1249138
File: 35 KB, 568x295, 1474866065629.png [View same] [iqdb] [saucenao] [google]
1249138

>>1249126
Collector current, continuous maximum.

>>1249129
Yes, everyone sucks the first time, and no, you shouldn't just off yourself now. You *can* solder like John Gammell if you have reasonable fine motor control and the right equipment and supplies.
http://www.solderingtraining.c om/gallery.php

>> No.1249140

>>1249126
>>1249138
Pic related is just a sample from an NXP datasheet I had handy, not the BC945.

>> No.1249141

>>1249118
BC945 does not exist. If it has C945 on it, it's a 2SC945 which is NPN but you need a PNP transistor.

>> No.1249143

>>1249141
Yeah, I noticed after I posted, sorry

>> No.1249145

>>1249140
I noticed that. The c945 (bc945 was a typo), only has 0.15A. so... No cigar.

>> No.1249151

>>1249137
>>1249138
Idk man, I watched a couple of videos and they all said to tin the tip, so i tried but the solder either traveled up from the iron tip or just melted on itself. So the tip was still naked even after ~1cm of filament was used up. Then I tried soldering the joints anyway by heating the wire of the component on the board and getting the solder in there after a few seconds but whenever I tried the solder would just stick to the iron instead. Pretty frustrating experience.

I swear between this and figuring out the component values from the colors/cryptic codes I'm going insane.

>> No.1249157

>>1249151
The iron could be too cold, and/or you might need to apply extra flux. Also you want to wipe off any blobs of solder onto a wet sponge just before you apply heat to the joint, heat both the component lead and the pad, and apply solder to the joint between them. It wouldn't hurt to gather up a few disposable boards just for practice.
>figuring out the component values from the colors/cryptic codes
Also gets better with practice. SMDs are even more of a pain in the ass to scavenge for just this reason.

>> No.1249161

>>1248932
LED brightnessis directly related to the supplied current.

555's usually can't give much current, so you need to use a current amplifier. A simple transistor circuit should be able to do the job.

>> No.1249162
File: 6 KB, 240x180, tip.png [View same] [iqdb] [saucenao] [google]
1249162

>>1249145
>only has 0.15A
That would be enough, but you need PNP as a high side driver for the second TIP31.

>> No.1249174
File: 7 KB, 257x184, npn.png [View same] [iqdb] [saucenao] [google]
1249174

>>1249162
Finally: the NPN-only version, somewhat lossy..

>> No.1249182

>>1249174
Thanks, man. I'll give them a whirl when I get home tonight. I appreciate all the advice from everyone.

>> No.1249184

>>1249145
It's likely that transistors in your donor device whose part numbers begin with A or B are pnp devices, and so you can use the first schematic.

>>1249174
>TIP31
>beta(min) @ 3A = 10
Embarrassing.

>> No.1249187

>>1249184
I have a large order of 5mm white LEDs coming in, maybe I'll use less LEDs and try simple flashing circuits. All this is for the marquee on my lethal Enforcers arcade machine. I wanted to have the backlight flashing like a cop lights

>> No.1249221
File: 12 KB, 1051x479, 1505781990860.png [View same] [iqdb] [saucenao] [google]
1249221

>>1249187
>simple flashing circuits
Heh heh heh, let me fix that for you :^)
This circuit will flash two outputs alternately for 3 beats out of every 10. The input comes from an oscillator running at about 5Hz, based on a 555 or whatever. The MOSFETs are selected for a low on-state resistance. Bipolar power transistors will drop too much voltage to give the full brightness you would want.

>> No.1249232

>>1249092
use a deoxit pen on it

>> No.1249234
File: 1.06 MB, 3264x2448, IMG_1993.jpg [View same] [iqdb] [saucenao] [google]
1249234

In b I asked what I could make outta this

>> No.1249242

>>1249234
cut that wire on the transformer off and use it to hook the motor up to the battery. if it runs, shove the motor's shaft into the usb port and use it as a paddle to nudge that ram off your desk and into the trash where it belongs. then kill yourself.

>> No.1249247

>>1249234
Give it back, Ahmed.

>> No.1249264

>>1249234
a cool clock

>> No.1249276

>>1248170
if you have the chronometer, all you need is the mass of the paintball and you have the force (at the point where the chronometer is).

obviously because of wind resistance, it won't be the final force of impact, but resistance is likely negligible here.

>> No.1249294

I want to pump as much power as possible from a lipo through a coil and want to know if my math is okay:

Let's assume a 22.2V 6S 6A 50C 100C lipo. The coil uses 5.7m long 1mm diameter of copper wire, which has a total of 0.12 ohm resistance. At fully charged 6 cells, if I shorted the lipo over the coil, it'd pull 25.2V / 0.12 ohm = 210A, right? That's only 35 times 6A, so < 50C.

Assuming my math is okay, can I just short it for as long as I want without the lipo going up in flames? I feel like I'm missing something.

>> No.1249300

>>1249294
i believe your math is right, but as i understand it the discharge ratings are optimistic. you could try to draw a known load and measure the voltage drop to estimate the ESR and thus the self-heating temperature rise, but i don't think it's linear.

what you really should consider is the heating of the coil at that current. ideally your coil would heat at 340°C/s: [(210A)^2*0.12 ohms / (5.7m*(1mm)^2*pi/4*9g/cm^3*0.385J/(g°C))] so it would exceed the melting point of common magnet wire enamel in about half a second. that's ignoring inductance and heat transfer which both should be negligible in that timeframe. it also ignores the rise in resistance at temperature. this might not matter to you though if you're only doing pulses.

>> No.1249302

>>1249161
So... The strips come in sections of 3 LEDs connected to each other. I measured the draw on one section (3 LEDs) with the meter set to 10A, and I got a reading of 0.04. then I connected one side of the alternating flasher, consisting of 20 little sections (60 LEDs) and I got a reading of 0.43.

>> No.1249306

>>1249300
Thanks for the info, didn't think about that yet.
So to be on the safe side, I'd have to limit the pulses to let's say 0.4s maximum or get a bigger wire, right?
Damn, PVC starts to deform at 92°C. That's even worse, that means I can't wrap the coil around it.

>> No.1249309

>>1249294
>without going up in flames
Probably, as long as your coil, pack and other connections are solid and thicc.

>>1249306
You may need to reinforce with something a bit more tolerant of high temperature, such as ceramic or (kek) wood.
Yeah you'd better put some thiccer wire on there.

>> No.1249333

>>1249306
Assuming this is supposed to be an electromagnet, the usual solution is simply to use more (thinner) wire. You'll get roughly the same results as long as the voltage and the total mass of copper remain constant, while the power consumption goes down along the wire diameter.

>> No.1249336
File: 48 KB, 599x337, ngbbs4bbfee956d10a.jpg [View same] [iqdb] [saucenao] [google]
1249336

>>1249333
Needs more magnets

>> No.1249339

>>1248170
slide potentiometer connected in non-reciprocating manner to stiff plate on a spring(but not a random one - you need to know what kind of force it does at given degree of compression) put in a square pipe with as little friction as you can.

The formula will be fairly simple it will be something like:

F = Vp/Vcc * [length of potentiometer's slide] * k(spring's force multiplier)

>> No.1249357

>>1249006
The ARRL Handbook - 70s or earlier edition. Depending on how deep you want to go, there's also the Radiotron Designer's Handbook. It's available online. Too lazy to Google just now...

>> No.1249438

Hey guys, I'm trying to build a co2 sensor for a refrigerated chamber, using a MQ135 and an arduino UNO board. I saw a lot of videos and stuff showing how to properly calibrate these sensors but I don't know if they're reliable enough for 24/7 operation. Does anyone know of a better sensor for the job or any other way I could do it?

>> No.1249510

>>1249333
>>1249309
For the flyback diode / resistor, what current do I have to expect? When shorting the lipo over the coil, it draws the 210A, but does the flyback diode really need to deal with that much current? Or can I just use some high voltage diode for a lower current?

>> No.1249526

Hello. When Is a 100 MHz signal generator useful? I have the ability to buy one. Its output is measured in micovolts. Im a beginner.

>> No.1249529

>>1249526
>wanting to buy a tool you dont even know what its for

>> No.1249536

>>1249529
I already have a 2 MHz signal gen. I just wanted to ask if higher frequencies will be useful later on.

>> No.1249539
File: 30 KB, 462x412, file.png [View same] [iqdb] [saucenao] [google]
1249539

>>1249510
the flyback diode will theoretically conduct 210A for a fraction of a microsecond. it only needs to be pulse rated for that, but most diodes have pulse ratings listed for a half mains cycle (~8ms) so you'll inevitably end up with a much bigger diode than you need.

assuming you're switching this coil with a fet and not a relay (please don't try to break 210A with a shitty relay) then the relevant parasitic elements are in pic related. the diode's inductance will try to prevent the inductor current from flowing through the diode as the fet is turned off, which will result in a voltage spike as the coil tries to force the current through the diode anyway. a capacitance (or RC snubber) directly across the fet can counteract this if it's sufficient. in less extreme cases the fet's inherent capacitance can manage sufficiently but not for you. the implications of this are that your diode won't ever actually see 210A, and your switch will see a voltage spike that could kill it if you don't add a snubber.

>> No.1249542

>>1249536
It depends on what you're going to do in the future.
>measured in micovolts
Sounds like it's intended primarily for radio stuff.

>> No.1249544

>>1247660
How do I multiplex Arduino's Due PWM pins to drive more than 6 different LED's signals without any detectable flickering?

>> No.1249545

>>1249536

your 2Mhz generator is too low for high-speed logic testing, and certainly for radio stuff, like 49Mhz RC car receivers. however, given that RF circuits nowadays tend to be in 400Mhz+ range, a 100Mhz generator is not gonna find too much use. so, i'd buy if only if it's really cheap, like $20.

>> No.1249546

>>1249544

simple math. you want about 50Hz min per LED to avoid flickering, so with 6 you have to MUX them at 300Hz or better.

>> No.1249547
File: 21 KB, 666x239, sploation.jpg [View same] [iqdb] [saucenao] [google]
1249547

>>1249510
That's the beauty of inductors: in the moment of switch-off, the current is the same as it was before. It just keeps on flowing no matter what because the stored energy has to go somewhere and it definitely will find a path.

The good thing is that your contraption will not draw 210A for long (if ever) because 20V*200A=4kW and 20V*6Ah=120Wh which means 120Wh/4000W=108s. Given the loss of capacity at that load level I'll give it less than a minute. Just enjoy the seductive fragrance called Fleur d'Ampère and let it expire naturally. What was the internal resistance of the lipo again? Enough for another kilowatt?

>> No.1249548 [DELETED] 

>>1249545
It comes from the military. It Has an external power supply. It was made about 1960. The seller wants 90$ for it. I think im gonna save the money and later buy a better one. Thanks for your help

>> No.1249549
File: 134 KB, 934x700, 519942028_1_1000x700_generator-falomierz-wojskowy-koszty-wysylki-w-cenie-wronki.jpg [View same] [iqdb] [saucenao] [google]
1249549

>>1249545
Pic related is the generator.. It Has an external power supply. It was made about 1960. The seller wants 90$ for it. I think im gonna save the money and later buy a better one. Thanks for your help

>> No.1249550

>>1249549
oh god

>> No.1249561
File: 34 KB, 719x442, MG811.png [View same] [iqdb] [saucenao] [google]
1249561

>>1249438
MQ135 is not for CO2, it's a low quality 'air quality' sensor. Look for MG811 instead.
>refrigerated chamber
difficult, sensors are heated to 20..28°C, lowest ambient temp: MQ135 -10°C, MG811 -20°C

>> No.1249572

>>1249561
I found this one: http://sandboxelectronics.com/?p=1126
because its operating temperature is from 0°C to 50°C since the chamber I'm working on is just for potato refrigeration, it works at around 6°C.
and for the humidity problem I'm still thinking.

>> No.1249573

>>1249561
>>1249572
and I think that this infrared boy is more reliable long term, because these chemical sensors need a heating element, it could blow up anytime since its probably chinesium

>> No.1249586

I have a drone that carries an Arduino with a sensor.I'd like the Arduino to trigger the sensor to take a reading every time the drone reaches a waypoint. How the hell could this be accomplished?

>> No.1249594

Do you guys think a physical copy of The Art of Electronics 3rd ed is worth it?

I kind of want a reference manual.

>> No.1249596

>>1249594
do you commonly read textbooks when studying a subject? that's your answer.

>> No.1249598

>>1249539
Awesome, thanks. I think I figured out the parts, though I may have chosen too big ones:
Diode - P2500M 1kV / 500A surge rating
MOSFET - IRFP90N20DPbF 200V / Pulsed drain current 380A

I'm wondering what would happen if I put two lipos in series: If I = U / R and U = 50.4V, R = 0.12 ohm, then I = 420. That'd probably fry everything involved in just a moment, right? On the other hand, there's probably a lot more resistance in the whole thing than just the 0.12 ohm of the copper wire, so there's a chance the components would survive something like that.

What you're suggesting is adding a small capacitor in parallel to make the MOSFET survive the initial current that isn't caught by the flyback while it boots up, correct? But if the MOSFET is rated for example the 200V above, it should resist long enough for the flyback diode to start working, or am I missing something? I mean, how much can the voltage spike till the diode kicks in?

>> No.1249599

>>1249596
I mean, do you think it will be something I will come back to in a few years.

I like the PDF copy but I'm wondering if it's worth the $100 or whatever.

>> No.1249600

>>1249586
GPS?

>> No.1249608

>>1249599
i don't read textbooks and never did in college so i wouldn't recommend it. it's too subjective for there to be one answer though.

>>1249598
your mosfet is rated for 94A continuous (with an ideal heatsink, which doesn't exist). the pulse rating only applies for the flyback diode because it only does anything in the moment you turn your fet off. your fet will dissipate on the order of 1000W. a standalone fet can handle about 1W. a realistically sunk fet can handle 10-50W. when a mosfet is on, it's basically a resistor. the formula I^2R applies. you would realistically need 5-10 of those fets mounted to a chassis to sink 210A continuously. you're right that the 210A value is meaningless without considering your whole system though. give us a whole breakdown of what you're doing.

>> No.1249619

>>1249608
Coilgun.
I plan to keep a single coil running for only a very short moment, somewhere below 0.1s.

>> No.1249620
File: 136 KB, 1057x527, IUnkown+2.png [View same] [iqdb] [saucenao] [google]
1249620

I want to make this but I don't know what these boards are called.
Also what's the red squares? And the black lines are insulated cables? I've never followed one of these diagrams

>> No.1249638

>>1249619
do you coilgun guys ever simulate the dynamics behind what you're doing or is it just a fun experiment?

anyway, your total system resistance should leave you with 150A steady state current at most. you can use a single irfb4110 to sink that for 100ms if you mount it to a chunk of metal to act as a thermal capacitance. i did a quick circuit simulation which suggested that your diode shouldn't actually see over 100A peak considering all the little inductances in the system so just get what's most available. mount the diode directly across the coil to minimize inductance. solder a 1uF ceramic or three and a 10 ohm in series directly at the source and drain of the mosfet to act as a snubber. you "should" be fine.

>> No.1249640

>>1249638
if your coilgun melts, now you have a really hot stick to beat niggers with

>> No.1249646

>>1249638
Well I actually hope that the thing is working in the end, so a bit more serious than just an experiment.
How did you simulate this and how did you get the 150A?
I'll follow your advice and add the capacitor, but I'm having another issue: Trace width. I'm pretty sure the traces on PCBs are too thin to handle that much current, do I have to solder that stuff directly?

>> No.1249648
File: 271 KB, 784x702, Zhengzhou-Winsen-MH-Z16.png [View same] [iqdb] [saucenao] [google]
1249648

>>1249573
>probably chinesium
Certainly, lifetime 5 years.
co2meters has something about calibration:
www.co2meters.com/Documentation/AppNotes/AN131-Calibration.pdf

The air leaving your lungs has a CO2 concentration of 20,000 ppm. The air in the room you're sitting in has a CO2 concentration of 2,000..4,000 ppm and on the ISS it is 5,000 to 10,000 ppm.

>> No.1249652
File: 36 KB, 765x724, file.png [View same] [iqdb] [saucenao] [google]
1249652

>>1249646
i included the parasitics relevant to switching. there's some more small resistances to account for there but you can add those up. what are you putting onto a pcb, the fet and some control circuitry? don't put the diode on there. the rest will be fine as long as the wires going to the coil and battery are soldered directly adjacent to its leads and the traces are tinned.

>> No.1249656

>>1249652
Awesome! Diode directly to coil, rest onto the PCB, got it. You've been really helpful, thanks again.

>> No.1249676
File: 240 KB, 969x449, veroboard.png [View same] [iqdb] [saucenao] [google]
1249676

>>1249620
>I don't know what these boards are called.
I've never seen them before either.
One minute of search in google images for "horizontal trace perfboard" got me pic related.

>> No.1249677

>>1249676
Thanks! Now it's off to Aliexpress!

I think Ive figured out how to do this, the red suqres must be cuts in the board to interrupt the horizontal lines and the annotations at the sides must be the components I have to solder on left and right.

>> No.1249680

>>1249677
actually, I was wrong
Veroboard has .2" spacing
What you want is .1" spacing
Wiki:
>There are many types of "perforated prototyping board".

>The vast majority of such boards are perforated at 10 holes per inch both horizontally and vertically (also called "tenth inch spacing"), made out of either "synthetic resin bonded paper" or fiberglass, and have some kind of copper pattern on one or both sides of the board.

>Perhaps the most popular pattern is "stripboard" -- which has wide strips of copper running one way all the way along one side of the board, but no copper on the other side.

so look for stripboard perfboard

>> No.1249683

>>1249680
>Wiki:
>>There are many types of "perforated prototyping board".

Thanks for citing where you got the info from, I'll search for it myself next time, but I'm sure I've bought the wrong spacing board

>> No.1249693

>>1249544
Use a higher PWM frequency, and cycle your column selectors every several PWM cycles, say, 5-6 to start. To minimize jitter and bleed, have your new PWM data ready before changing column selectors, and consider resetting the timers when moving to the next column. Try to do the whole matrix in no less than 15ms. You will probably want interrupts or assembler.

>>1249546
50Hz flicker makes my brain hurt.

>> No.1249848 [DELETED] 

>>1249620

as mentioned, it's called stripboad, but most people call it veroboard, which is a brand name that's been made generic. the red squares mean you take a drill bit and break the copper trace at that point. the black lines are insulated wire jumpers.

software to create veroboard layouts is listed here: http://www.electroschematics.com/2270/veroboard-design-software/

the last one, LochMaster, is the best.

>> No.1249850
File: 80 KB, 500x363, lochmaster-stripboard1.gif [View same] [iqdb] [saucenao] [google]
1249850

>>1249620

as mentioned, it's called stripboad, but most people call it veroboard, which is a brand name that's been made generic. the red squares mean you take a drill bit and break the copper trace at that point. the black lines are insulated wire jumpers.

software to create veroboard layouts is listed here: http://www.electroschematics.com/2270/veroboard-design-software/

the last one, LochMaster, is the best.


>>1249693
>50Hz flicker makes my brain hurt.

then movies, at 24fps, must be hell on earth.

>> No.1249872

>>1249850
The duty cycle is much longer in film projection, and essentially 100% in digital projection, so no, movies are hell for reasons unrelated to electronics and entirely related to content.

>> No.1249876

>>1249599
We can't really decide that for you.
I bought the paper version of 3rd edition even though I had 2nd edition already. (Plus an illegally copied PDF version.) So, personally I think the physical version is worth having. For me, it a reference and an idea book, not something you read from the beginning to the end.

>> No.1249877
File: 57 KB, 910x217, Screen Shot 2017-09-25 at 2.06.07 AM.png [View same] [iqdb] [saucenao] [google]
1249877

>>1249876
Haha thanks for the advice man.

I made my choice

>> No.1250016

Sorry for the question that is probably retarded to you guys, but I'm not really electronic savvy, and I'm kind of stuck right now. I'm trying to power an old cordless drill motor, but I can't seem to get it working. I pulled the power supply out of an old radio, but when I hook it up to the motor, the motor just kind of vibrates. Is this power supply not putting out enough for the motor, or is the motor maybe junk? If the issue is not enough power, what can I use as a power supply that I might have lying around the house?

>> No.1250020

>>1249850
Nice, I didn't realize there was a veroboard specific program. There goes my evening.

>> No.1250047

>>1250016

a typical cordless drill needs 5-20A depending on the load. a radio transformer might give you 1-2A. (and the drill needs DC, but a bare transformer will be AC).

if the drill can work OK around 12V then you can probably use a PC power supply from an old computer. should be good for 20-30A. an XBox power supply might give you 10-12A at 12V. if 12V is too low or too high, then it gets complicated.

overall, this is a bad idea, tho i'm sure lots of youtubers have made videos about it. youtubers LOVE bad ideas.

>> No.1250058
File: 30 KB, 678x366, 1452850777.gif [View same] [iqdb] [saucenao] [google]
1250058

I recently got an old dual channel analogue oscilloscope for really cheap (Philips PM 3260). While channel A works alright from what I am seeing, I am not getting a trace for channel B. I read an old tektronix guide for troubleshooting, which told me to "milk" the front panel and all the buttons to see if I could determine what is wrong from there. I tried every setting that I could to try to get a trace or dot to appear on screen (I don't think that this scope has a beam finder button on it, so I don't really have a way to check if anything appears on screen), but was unable to get one to appear. On the front of the scope there is an LED that turns off when the scope is triggered, and when I applied the channel b probe to the test point or put my finger on the probe I was unable to get it to go off.

Because of this, I have (possibly wrongly) concluded that the issue with channel B is in the attenuator stage, mainly because I can not get the trigger light to go off, even when I set the trigger to channel B. Does my diagnosis sound correct? I feel somewhat weary of it, since I don't have experience with oscilloscope troubleshooting.

>> No.1250063

Hi!
I'm thinking about building a small power consumption analyzer. A one that can measure mains voltage, current, calculate phase, apparent, active and reactive power etc. I've figured that the best way to measure current is to use a Hall effect transfuder (preferrably ACS712 or a salvaged LEM, cant' afford a new one), and feed it to some MCU's ADC. But what about voltage? I'd like to have the signal separated from mains, so I could output both signals to BNC's to do other varius stuff. How about a small 5VA transformer (I need a small power supply anyway), but I'm concerned about some phase shift between mains voltage and transformer output. Trim it with a matching cap? Any other suggestions?

>> No.1250069

>>1247742
pretty cool, didn't even know this was a thing.

>> No.1250082
File: 9 KB, 300x300, Kill A Watt Electricity Usage Monitor.jpg [View same] [iqdb] [saucenao] [google]
1250082

>>1250063
>Any other suggestions?

dont re-invent the wheel. i got a used kill-a-watt for $3 at the thrift store.

>> No.1250113
File: 218 KB, 500x288, 1498362861622.gif [View same] [iqdb] [saucenao] [google]
1250113

any chance anyone here knows of a replacement for a SIGMATEL STMP 3151 SoC?
Trying to diy a mp3 player but I cant find any other chips that would do audio decoding that I can try and read up on.

>> No.1250131

>>1250113
ST has a bunch of mp3 decoder chips, including the STA013. There is also a software decoding library for the STM32 series provided by ST, as well as a few open-source ones which any 100MHz-class 32-bit micro should be able to use.

>> No.1250132

>>1250131
really surprised I haven't seen these before. thanks a fuckton

>> No.1250138
File: 215 KB, 886x572, pm3260.png [View same] [iqdb] [saucenao] [google]
1250138

>>1250058
Get the service manual, it is full of trouble shooting tips
www.google.com/search?q=philips+pm+3260+service+manual
There's a lot of repair stuff around for that scope.
You will need a good (10MΩ) multimeter and maybe a HV probe (2kV).

>> No.1250199

>>1249232
I used deoxit on the resistor film and the wiper. The inner wiper and axle got a dab of conductive grease. It says its super cancerous so it's probably the good stuff.

>> No.1250261

>>1248932
Shit, I've got some of those perfboards at home, from the local surplus store. They fucking blow, but 75 cents is still a decent deal

>> No.1250501

New to the industry and want to get some bench tools. What is the best mid range stuff to get. I want a fully equipped bench.

>> No.1250507

>>1250501

there is no answer to this question in 2017. everything is made in china, and quality is highly variable from one model to the next. there are no safe harbours; it's all a crap-shoot.

>> No.1250508

>>1250501
Can you elaborate on what part of the "industry"? A few tools are somewhat universal, (ie multimeter) but depending on what you are doing (power converters, embedded design, RF/microwave, etc etc) tools and their specs vary considerably.

>> No.1250511

>>1250508
Currently electronics technician going into telecommunications.

>> No.1250552
File: 69 KB, 800x800, s-l1600.jpg [View same] [iqdb] [saucenao] [google]
1250552

Whta happens if I try to drive one of these off a lesser voltage of, say, 60v?

>> No.1250566
File: 20 KB, 640x480, ElectretColorOrgan1.png [View same] [iqdb] [saucenao] [google]
1250566

Hi there! I built an LED flashing circuit triggered by a microphone. I'm using 12v led strips, and 2 tip31c transistors, plus the necessary resistors. When I powered the circuit with a 12v supply it worked perfectly, but then I used a 5v 1A supply with a step up converter (up to 12V) and now the LEDs just stay on. They still flash with sound, but they just turn on and stay on as soon as I power it up. What is going on? Pic related.

>> No.1250577

>>1250552
undervoltage shutdown

>> No.1250578

>>1250552

Depends on how it's constructed internally. It might simply draw more current on the input for the same output (although I would derate it by half even if it worked). It might have some low-voltage cutout kick in and not work at all. It might fail spectacularly, if it's particularly shitty.

>> No.1250609

>>1250566
Your step-up converter probably produces lots of noise and the circuit sees it as "sound".
You can try filtering the power supply of everything to the left from the LED strip. For example, add a 100µF capacitor in parallel with the supply rails and take the positive power via a 100 ohm resistor.

>> No.1250612
File: 2.13 MB, 4128x2322, 20170926_101933.jpg [View same] [iqdb] [saucenao] [google]
1250612

At my work place, we got a monitor that wasn't working anymore (LG 34UC97). I took it home and tore it apart (pic), but I can't seem to find anything out of the ordinary (black marks).

There is power to various areas and various components on this board, but nothing shows up on screen at all.

Any ideas what I should look for?

>> No.1250616

>>1250612
First thing to check is backlight, try connecting it and shining a light on it, if it's backlight then you'll see image.

>> No.1250621

>>1250566
>Light to Sound with an Electret Microphone
>sound makes light flash
Shouldn't that be a "Sound to Light with an Electret Microphone"?

>> No.1250622

>>1250612
Blown caps, number one cause of monitor failure.

>> No.1250625

>>1250612
>Any ideas what I should look for?

you're looking at the wrong board. you wanna examine the ''power supply/inverter board'' coz all the bad things happen on the nigger side of town.

>> No.1250630

>>1250621
I thought it sounded weird, but the place where I got the schematic was out up by some Indian guy, so I attributed it to translation quirks. I'm sure it sounds like it makes sense when they say it in their language.

>> No.1250632

>>1250609
So the capacitor from supply to circuit, and resistor from positive to LEDs?

>> No.1250649

>>1250616

There is literally nothing on the screen, so it is not the backlight.

>>1250622

That's what I thought, but none of those caps on that board looks blown

>>1250625

The power supply is external. It comes in as a 20 VDC and the input works fine. Unless you're talking about something else...

>> No.1250671 [DELETED] 

>>1250649

an external power supply is a big plus coz they're easy to replace. however, if it's an LCD (as opposed to an LED) machine, then it will need inverters (transformers) to drive the CCFL lamps. if you're courageous, you can try reading the lamp voltages, which could be 800-1200 Vac.

also, reading 20V on the supply doesnt necessarily mean it's good. it could have several volts of noise which a multimeter will not pick up, but which makes it useless. you need a scope, or a replacement, to exclude that possibility.

>> No.1250673
File: 125 KB, 490x370, LCD inverter board.jpg [View same] [iqdb] [saucenao] [google]
1250673

>>1250649

an external power supply is a big plus coz they're easy to replace. however, if it's an LCD (as opposed to an LED) machine, then it will need inverters (transformers) to drive the CCFL lamps. if you're courageous, you can try reading the lamp voltages, which could be 800-1200 Vac.

also, reading 20V on the supply doesnt necessarily mean it's good. it could have several volts of noise which a multimeter will not pick up, but which makes it useless. you need a scope, or a known-good replacement, to exclude that possibility.

>> No.1250675

Figured this is the best thread to ask. I have an interference issue with my amplifier: the HDMI lead I use to connect to my TV seems to cause a hum in my amplifier when I connect both the amplifier and the HDMI lead to the same source, like a laptop. Could it be some kind of ground loop, despite the fact that only the amplifier is grounded?
And can I fix it by soldering in a resistor in the ground of the amplifier?

>> No.1250676

>>1250673

It is an LED monitor...so you suggest I replace the power supply?

>> No.1250682

>>1250676
>so you suggest I replace the power supply?

i'd never suggest replacing something without confirming it's bad. i just meant replacing it temporarily as a diagnostic test. e.g. maybe there's a similar monitor at work you could borrow the power supply from. or you know someone who has a lab power supply.

>> No.1250683

>>1250682

OK, I'll see what happens if I use this power supply on another work monitor when I get back to the office on Friday.

>> No.1250716

>>1250675
Try opening the ground of the audio cable entirely.

>> No.1250757

>>1250566
>Pic related
Circuit doesn't look kosher.

>> No.1250759

>>1250757
The circuit works perfectly with a regular power supply. I think it is the step up converter as someone mentioned earlier. I did notice that a component on it looks a little rough, as if someone mashed a soldering iron on it for a couple of seconds by accident. I'll try another one and see what happens.

>> No.1250766

>>1250759
How much current does the LED strip draw? How much current does the step-up converter supply? (probably around 300mA)

>> No.1250768

>>1250766
The step draws 450mA. The supply can put out 2A. Current supply isn't the problem. They light up beautifully, but when I use the converter, they just stay on once your activate then, as opposed to the regular supply, which let's them react to sound.

>> No.1250771

>>1250768
You said you were driving the boost converter with a 5V 1A supply. Please don't tell me you think you're getting 1A, much less 2A, on the output of that converter, when driven by a 1A input.

>> No.1250801

>>1250771
My bad.. the 12v supply is 1A. The 5v supply IS 2A. Either way, the current is fine. The LEDs light up as bright as they do when connected directly.

>> No.1250805
File: 2.25 MB, 4128x2322, 20170926_191533.jpg [View same] [iqdb] [saucenao] [google]
1250805

>>1250612

A slight followup to this. I discovered there was another board that this is connected to the main board (I googled around and this is called a T-Con board). The T-Con board doesn't seem to be getting any power and I notice two of the gray things are getting kinda warm.

>> No.1250812

>>1250801
So the output of the step up converter will be ~800mA - losses which is a bit better margin. Alright.
I'm going to go with the circuit being designed for 3.6V, not 12V. Supply voltage matters with resistor-biased linear transistor circuits. Consider running the "logic" part of the circuit, i.e. everything but the LEDs, off the 5V supply, which will be close enough to the design voltage to probably work, and hook the 12V output to the LEDs only.

>> No.1250816

>>1250812
I thought the circuit was 3.6v because of the single led, that's why I thought that feeding it 12v was ok as long the output was a "12v" led (a 12v led strip,in this case).

>> No.1250847
File: 16 KB, 360x360, usb_micro_female2.jpg [View same] [iqdb] [saucenao] [google]
1250847

I want to make some usb cables
any tips for soldering tiny wires to pic related?
there's so little space, I need some sort of pro technique

>> No.1250849

>>1250847
>any tips for soldering tiny wires to pic related?
Don't.

>> No.1250850

>>1250847
Youre supposed to solder that to a board
Do you have a soldering station?

>> No.1250851

>>1250849
>Do you have a soldering station?
yes

>> No.1250852

>>1250851
how I managed to quote the wrong post but the right line, I do not know

>> No.1250865

>>1250816
Nope, the left and center transistors are passing ~3x the current they would at 3.6V Vcc. The output driver can be connected to any voltage the device can handle.

>>1250847
You'll need a board.

>> No.1250869

>>1250865
>You'll need a board.
ok, how about I create a small board the size of the mini usb
and then manually apply 5 tiny pads to it, then solder the socket and wires to that
got any pro tips for making homemade ghetto solder pads?

>> No.1250874

>>1250869
Personally, I'd probably just send out to OSHpark or your local pcb pool. 10mil trace/space probably ain't happenin' with micro fine Sharpies.
I suppose you could solder if you had some pliers that could hold all the wires in place, some double-sided tape to hold the connector in place, some hot glue to keep things from moving around when you're done, a steady hand, and a taste for masochism and swearing.

>> No.1250909
File: 801 KB, 3080x2088, cctv.jpg [View same] [iqdb] [saucenao] [google]
1250909

Any opinions on hikvison or dahua from ebay? this is more a /g/ question but since ill be buying parts alone its sorta /diy/

>> No.1250919

>>1250847
>I need some sort of pro technique

you'll need a fine tip iron, some fine leaded solder with a flux core, like 0.4mm, 30 gauge wire-wrapping wire, and some small heatshrink or plastic tubing (possibly the outer layer of a 24-gauge wire)

- tin all the connections and wires
- start from one end, and solder 1 wire
- cover it with heat shrink so it wont be reheated
- move on to the next until all done
- test it, then cover it all in epoxy or hot glue

you only need 4 wires, so one pin is unused. make sure you know which one.

>> No.1250921

>>1250919
With Micro USB you should ground the ID pin on the host (usually micro-A) end of the cable to be fully compatible with USB-OTG.

>> No.1250943
File: 8 KB, 443x123, 50 ohms.png [View same] [iqdb] [saucenao] [google]
1250943

I'm actually retarded and I can't figure out how to find the resistance of this circuit. I know it's supposed to be 50 ohms, but I don't get that when I try to calculate the resistance.

>> No.1250945

>>1250943
7+19+10 = 36, 36 in parallel with 36 is 18, 18 in series with 4 and 8 is 30, 30 in parallel with 30 is 15, 35 and 15 is 50 Ohms.

>> No.1250947

>>1250945
Thanks! I was doing it backwards and kept getting hung up on the 8, 30, and 36 ohm resistors.

>> No.1250954
File: 2 KB, 163x198, 10F.png [View same] [iqdb] [saucenao] [google]
1250954

>>1250759
Please post a photo of your circuit. I want to see the 10F capacitor, the 100µF coupling Cs and the totally idiotic 20Ω resistor at the bottom of the 10K pot. How do you run your 12V LEDs from a single 3.6V cell?

>> No.1250962
File: 73 KB, 1000x1000, alien_220w_kit_by_smok_7clr-2.jpg [View same] [iqdb] [saucenao] [google]
1250962

Pretty new to electronic tinkering and I'm thinking about trying to modify a tank so I can hook it up to my car and use it as a jumpstarter. Is a 220w battery enough? Has anyone tried this before? Pic related.

>> No.1250970

>>1250962

google says you need 12v ~ 300amps to start a small car. so about 3600w to turn it over.

>> No.1251007

Has anyone here been to trade school to train as an electrician? Other than reading books in the OP is there anything recommended to know before attending?
Sorry if not the place to ask

>> No.1251012
File: 1.40 MB, 3120x3120, IMG_20170927_112728.jpg [View same] [iqdb] [saucenao] [google]
1251012

>>1250954
You know? I just noticed I posted the wrong circuit originally. I had no idea I had the wrong picture up. This is my circuit, though. The circuit I posted originally I disregarded because I thought it was a joke. To answer your question: I was powering it with a 12V 1A power supply, and it worked perfectly, but then I switched to a 5V 2A supply with a step up converter, and the lights just stay on. I think the converter sucks.

>> No.1251013
File: 1.36 MB, 3120x3120, IMG_20170927_113544.jpg [View same] [iqdb] [saucenao] [google]
1251013

>>1250954
This is the first build. I have since made it a bit smaller and used better perf board (the green ones with the metal holes, not this paper shit with painted on metal at the bottom)

>> No.1251061

>>1251012
The converter will output up to 0.83 A, assuming it can actually handle that much (easy) and has no loss (it probably has little)

>> No.1251095

>>1250847
You want the thinnest solder you can find, and probably a chip holder with magnification. Soldering tiny things by hand can go really badly, but bags of usb heads are pretty cheap in bulk

>> No.1251101

>>1251095
Maybe you want that, but if you use suitable techniques, you don't need thin solder or sharp tip. Special tips help, though.
https://www.youtube.com/watch?v=5uiroWBkdFY

>> No.1251184

>>1251012
How about you post an ACTUAL schematic of the circuit you're building instead of wasting our time with irrelevant jokes?

>> No.1251187
File: 22 KB, 275x395, harrharr.jpg [View same] [iqdb] [saucenao] [google]
1251187

>>1250909
diy too

>> No.1251189
File: 195 KB, 1154x917, av switch.jpg [View same] [iqdb] [saucenao] [google]
1251189

I can't stress enough that I am a COMPLETE beginner when it comes to electronics, so bear with me.

I got this neato 8 position switch and thought I could make a/v selector switch of sorts that has four rgb and four component inputs by pulling the board out of my rgb to component converter and cobbling it together with the connectors and the switch. See my really shitty diagram if that didn't make sense.

My problem boils down to a lack of knowledge here (especially about what I need to do in that yellow box): How can I use the switch to control which input is connected to the output? Is there a way to have the switch control a switch that has more pins (ie if the dial switch is turned to 1 it takes the signals from input 1 and feeds them through to the output)?

Another problem is how to tell if the input needs to be fed through the converter or not. In the case of Component video I have Y, Pb, Pr, L Audio, R Audio (5 signals) and for RGB I have R, G, B, Sync, L Audio, Right Audio (6 signals), so surely I can check if the sixth signal is active with a detector and then either trigger or not trigger a switch the reroutes the signals through the converter?

Does this make any sense? I tried googling for a switch that is toggled by a current but I didn't find what I'm looking for.

I know I am a total beginner and this is probably all idiotic, but can someone at least ballpark me into the right direction with this?

>> No.1251190

>>1251189
Relays. It'll cost you a bit, perhaps, but it's the easiest and least critical way to do it.

>> No.1251197
File: 73 KB, 827x529, 61Kq7RK9jAL._SL1100_.jpg [View same] [iqdb] [saucenao] [google]
1251197

>>1251190
>Relays
Amazing. Thanks!

Is pic related (more or less) effectively how a relay is wired? I want to make sure I understand what I'm doing before I buy them because it does seem like they cost a fair bit

>> No.1251202
File: 30 KB, 528x464, 1486848259080.jpg [View same] [iqdb] [saucenao] [google]
1251202

>>1251197
Eh, not really. You'd probably want to use reed relays, as they will disturb the video signal less. Middle two are the coil, just parallel them off the rotary switch, and the outer two are the signal. They cost a burger and up each, and you'll need five for each input. I know next to nothing about SCART but I can tell you YUV is incompatible with RGB and the converter adds a whole other level of hassle.

>> No.1251204

>>1251197
thanks for the laugh dude

>> No.1251208

>>1251202
Oh I see, this makes a lot more sense than what I was looking at.

Believe it or not I've already figured out the converter (currently just using it with a SCART switch daisy chained into it which is then daisy chained into a component switch) really this whole project is kind of just to mess around / learn a bit and hopefully end up with a single box rather than three with cables running between each of them.

>> No.1251209

>>1251189
ideally you use a series of analogue multiplexer. analogue because your signal is analogue and multiplexer because you want to either go one to many or many to one.
have a read of this, page 17 onwards.
http://cds.linear.com/docs/en/application-note/an57fa.pdf
it might look a little scary if you are a complete beginner but the theory should be interesting.

as for converting SCART is quite interesting because its just a big plug with loads of different connections bundled in, RGB is actually in there the problem is that the source and/or viewer may not support RGB via scart. i'm a little rusty but if you check wiki https://en.wikipedia.org/wiki/SCART you see RGB on odd pins 9 to 15.

your problem is that you need a 5P8T (5 pole 8 throw -> means 5 pins are connected (for R,G,B,L,R (assume all grounds connected) and 8 positions for all the sources)
what you have is i can only assume 2P8T, the two middle pins connect to a pair of pins at each position. so you need to expand this 2 poles out to switch 5 poles instead.

>> No.1251220
File: 15 KB, 650x737, 1503393090056.png [View same] [iqdb] [saucenao] [google]
1251220

>>1251208
The trick you'll need is diodes to do the wired-OR function to switch in the converter when any of the SCART inputs are switched in. You'll want to build this all into a grounded metal box to avoid RFI/EMI.

>> No.1251231

>>1251209
Thanks. I think this is a little bit over my head but I've saved all this so that I can come back to it as I go and hopefully make more sense of it as I learn more as I am really interested in pretty much everything to do with audio/video signals

>>1251220
This is incredible thank you!

>> No.1251240
File: 3.34 MB, 3989x1522, 20170927_201601.jpg [View same] [iqdb] [saucenao] [google]
1251240

babby's first current mirror

does anyone know what I can do with this thing? i don't have an oscilloscope, multimeter or function generator. they made me buy it for my electronics 2 lab

>> No.1251260
File: 28 KB, 702x425, export.jpg [View same] [iqdb] [saucenao] [google]
1251260

>>1251184
Here you go

>> No.1251270

>>1251240
Get a $20 multimeter. You're mostly blind without it.

>>1251260
Ah, much better.
Okay. First, try replacing Q1 with a transistor that has beta closer to 100, such as your average small-signal NPN like 2N3904 or whatever. TIP31s don't have enough gain to take a tiny little microphone signal and turn it into something useful.
Second, C1 may be backwards or too big. The negative lead should be towards the base of Q1, and try 1uF or even 0.1uF if you're still having trouble.

>> No.1251278

>>1251270
I'll try reducing the capacitor value. The thing is, the circuit works as it should with a regular supply, but when I use the step up converter the LEDs just light up as soon as they're activated and they STAY on instead of only flashing with a signal from the mic. I was trying to find out the cause as related to the converter. Someone said the converter might be making noise, and the circuit sees it as sound coming through the mic. If that's the case, what kind of filter can I put together on the Vin part to clean it up. I apologize if it's something simple, but I'm like the guy from the Lego movie: I can build huge, awesome things, but only when reading schematics. I can design pcbs to implement already made circuits into useful hardware and nifty gadgets, but if you ask me to design a circuit, I couldn't do it if my life depended on it. I just don't know enough yet. I've only been dabbling in electronics for a about 4 months in my free time. Thanks for the help.

>> No.1251285
File: 1.52 MB, 3264x2448, Photo Sep 27, 9 24 40 PM.jpg [View same] [iqdb] [saucenao] [google]
1251285

hey guy i bought this radio at a pawn shop and it works great but the cassette player is busted, i was wondering how i could fix it it just plays at a reduced speed till it finally stops also cant find the model on the web

>> No.1251290

>>1251285
Are you sure it's not the tape?

>> No.1251291

>>1251220
That's going to be 35 relays total, not exactly the cheapest or smallest way to do it. Going multi pole and/or two position relays may be useful.

>> No.1251293

>>1251285
First thing I'd try would be replacing the drive belt.

>> No.1251295

I kind of want to get into FPGAs. How expensive is it to get started? I heard they're kind of pricey, and I'd imagine whatever additional hardware and software you need to program them isn't cheap either.

>> No.1251297
File: 49 KB, 1408x702, 4017.png [View same] [iqdb] [saucenao] [google]
1251297

Can I directly drive LED's with a cd4017?
This is the circuit I have right now, soldered onto a PCB. I checked that all the connections work, and that the clock is being pulsed properly, but only the LED on pin 1 of the 4017 stays lit.
Am I fucking up something in my circuit, or just misusing the chip?

>> No.1251303

>>1251278
>STAY on instead of only flashing
That implies that Q1 has turned off and isn't turning on. TIP31C current gain is rated as no more than 50, and can be as little as 10. If you can't replace the transistor with something more suited to amplification, you could try reducing R2 to more like 220k or 100k and see if it behaves better.
>noob
No problem. We were all there at some point.

>>1251291
You could also use five CD74HC4051 8-to-1 multiplexers, if you also include dc blocking caps on the inputs.

>>1251297
It should work. Have you tried manually clocking the 4017 with a pushbutton or something?

>> No.1251306

>>1251303
I checked on the scope, it's being clocked every half a second or so, and the reset pin is held low too, so it's not an issue with that.

>> No.1251307

>>1251306
You're not trying to drive a 5V CMOS chip with a 3.3V signal, are you?

>> No.1251309

>>1251307
No, it's 5 volts from the arduino.
I haven't done anything that retarded in a while.

>> No.1251314

>>1251309
Kek, just checking. Is it a CMOS-level output? Is it actually reaching the upper rail? Some CD4000s are picky about that. Other than that, everything looks in order. That's why I'm suggesting removing the device from the circuit and manually exercising it.

>> No.1251315

>>1251309
Oh, also 100nF across each chip's power input?

>> No.1251317

>>1251315
Neither of them have that actually, but the shift register is working fine without it. I'll go try that real quick though and see if it does anything.

>> No.1251319

>>1251290
yeah i bought a new cassette
>>1251293
is that the part that reads the actual cassette tape or that moves the knobs

>> No.1251320
File: 705 KB, 738x780, 1473650662640.gif [View same] [iqdb] [saucenao] [google]
1251320

>listen to The C++ Programming Language audio book every night while I sleep
>become a pro C++ programmer with no effort

>> No.1251323
File: 3.67 MB, 4160x3120, IMG_20170927_205203.jpg [View same] [iqdb] [saucenao] [google]
1251323

>>1251315
That didn't seem to do anything unfortunately, still just keeps the first LED lit.
Here's a picture of the board itself if anyone wants to check it out. Forgive the awful soldering, I'm new to SMD parts, and I tried drilling out the hopes before cleaning the toner off with a drill bit that was slightly too big, so some of the pads around the holes didn't wet properly.

>> No.1251327

>>1251323
You're supposed to have one resistor for each LED

>> No.1251329

>>1251327
It's a counter, it only outputs one pin high at a time, one resistor should be enough

>> No.1251332

>>1251327
Never mind, that only matters if you want to turn on more than one at the same time, which seems to not be your case

>> No.1251333

>>1251329
And you really did mean pin 1, as in Q5? Weird af. Checked with a continuity tester for solder bridges etc? Gave everything a good scrub with alcohol and a brush?

>> No.1251334

>>1251333
I meant the first LED, which is actually pin 3, looking back at the schematic, sorry about that.

>> No.1251336

>>1251323
that looks like a nightmare. do a rigorous test for continuity and shorts in that circuit.

>> No.1251346

>>1251333
>>1251336
I just scrubbed it down and checked for any continuity in the wrong places and didn't find any, and I verified that everything is connected properly.
I'm not sure what to do next short of soldering in a new chip, or replacing the 4017 with a shift register instead on a new board.

>> No.1251349

>>1251346
Well, the chip doesn't seem to be clocking. If there is in fact continuity between the pins on your connectors and the respective leads of the chip, then the chip itself might be damaged. Have you got another unit of the 4017?

>> No.1251350

>>1251346
breadboarding is the best way to test out what you want to do. also, if not already, get a pdf of that chip's data sheet so that you see the internal circuit.

>> No.1251351

>>1251349
I do, I can go try putting a fresh one in. I probably destroyed the last one by overheating it while I was soldering, so I'll try to be a bit more careful this time.

>> No.1251359
File: 161 KB, 800x800, 4NFLS-LED-Light-Strip-Cut-0011.jpg [View same] [iqdb] [saucenao] [google]
1251359

I hate the lighting in my room, so I'm going to DIY something with LED strips, gonna run them most of the ceiling and diffuse them somehow, with PWM to adjust the brightness. I need to find some reliable LEDs with a good color temperature(Somewhere 4000k-5000k or so). Do you guys have any suggestions on where to source them? I'm not looking for anything particular, the project is built around the LEDs, so I don't care about connectors or how many run in series or what.

>> No.1251361

>>1251359
Aliexpress, of course. I did some lighting with these and I'm very happy
aliexpress com/item/5050-Double-Color-Temperature-LED-Strip-One-Chip-with-Warm-White-and-Cold-White-DC12V-60LED/32298725565.html

>> No.1251412

>>1251349
I replaced it with a new one and got the same behavior as before, so it seems like it's something with the chip itself, and it can't be used in whatever way I am.
I'll whip up a new board with 2 fewer LEDs using a shift register to drive them tomorrow, it's only a slight change from the board with the 4017.

>> No.1251413

Can I add an arduino bluetooth shield to an esp8266 to get a bluetooth connection to a mongoose OS application?

Waiting for the ESP32 to get better bluetooth coverage so mongoose OS can integrate it properly is making me impatient.

>> No.1251439
File: 1.11 MB, 640x480, VID_20170928_124125.webm [View same] [iqdb] [saucenao] [google]
1251439

Hi DIY!
/cgl/ cosplayer here wondering why my remote controlled smoke machine does not want to turn off.
My circuit is:
A 3.7V 18650 li-ion battery
A rc mini relay receiver
A cartomizer to evaporate the fog liquid
A tiny air pump to pump the fog out the cartomizer
A mosfet to reduce the current needed for the cartomizer since the rc receiver cannot handle it.

So it does actually work, it just doesn't want to turn off with the remote control. It does turn off when I use the learning button on the receiver, but that would defeat the RC purpose.
Sometimes it actually turns off, and it depends on the battery i use, which makes me wonder if the voltage over different batteries is the culprit.

>> No.1251440
File: 1011 KB, 640x480, VID_20170928_124249.webm [View same] [iqdb] [saucenao] [google]
1251440

>>1251439
other battery (protective shielded)

>> No.1251442

>>1251359
Adding, I got some aluminum channel from the local home improvement store and mounted them in it. The next step is to mount them to the wall but I'm still getting my 3d printer dialed in enough to print large objects.

>>1251412
Unless there's a hairline defect in the copper or something like that, I simply do not see anything that's wrong there. Oh well, HC595s are cheap and easy. I still wish you would have hit them with some hardware switches.

>>1251439
>relay
Is that receiver rated for 3.7V? Most relays are specified for 5V only. I wonder if the RF/control parts of the receiver are too. Maybe you could add a step-up converter that feeds it a solid regulated 5V.

>> No.1251444

>>1251442
Should be 3V-3.7V. I asked for a 3V one from this one: https://nl.aliexpress.com/item/Mini-Small-Volume-Wireless-Remote-Switch-System-Micro-DC3V-5V-Relay-Receiver-Transmitter-Momentary-Toggle-Latched/32603070541.html

>> No.1251447
File: 36 KB, 498x398, lackoflux.jpg [View same] [iqdb] [saucenao] [google]
1251447

>>1251346
>replacing the 4017
with a 74HC4017

>> No.1251449

>>1251442
I just tried clocking it with a button, didn't do anything but make the led on pin 3 slightly brighter when it was held.

>> No.1251454

>>1251449
>led on pin 3 slightly brighter
and what does that tell you?

>> No.1251483

I got a piezo transducer rated for 35W with an impedance of 20 Ohm.
Does that mean I can put an average voltage of U = sqrt(35W * 20 Ohm) = ~26.45V on it?

>> No.1251495

>>1251319
The belt between the motor and the mechanism that runs the actual tape.

>> No.1251496

>>1251483
yes

>> No.1251497

>>1251483
RMS, not average.

>> No.1251498

>>1251497
I'm planning to use PWM.

>> No.1251503

>>1251498
For square wave, RMS = half peak-peak voltage.

>> No.1251508

>>1251503
which is the average

>> No.1251510

>>1251498
>>1251503
but with PWM, RMS wouldn't necessarily be half Vpp right? If the width of the wave can vary...

>> No.1251517

>>1247660
Guys, I would ask a question.
I need to store a good amount of information (up to 48 Mbit) just once and randomly access that information using a 24-bit address line.

Seeing EEPROMs rarely are of more than 1 Mbit, would a NOR Flash Memory fit my requirements? Is there another alternative? What if I need to randomly access much more data (like 1 Gbit, for example)?

>> No.1251520

How are photoresistors rated? If I have a photoresistor how can I make sure I'm buying more of the same ones?

>> No.1251527

>>1251520
>How are photoresistors rated?

each model is unique. to get a matching one, buy all the same model.

>> No.1251543

>>1251517
Yeah, flash is today's solution to that problem.
1Gb parallel interface flashes are available and they aren't very expensive. Alternatively, you can use multiple smaller flashes.

Other options would include RAM with battery backup, bridge converting your parallel bus to some suitable serial bus (and using serial flashes and memory cards) and some obsolete memory types like PCM. RAMs with built-in backup battery are available, but afaik you'd need several to get 48Mb worth.

>> No.1251547

>>1251520
The primary parameters are the material (and spectral response), maximum power, maximum voltage and the resistance under specified lighting.
Power and voltage rarely matter and unfiltered types made of the same material usually have the same response, so matching material and resistance might be enough. And many circuits using LDRs work reasonably well with any common LDR.

That said, doing what >>1251527 said is the simplest option.

>> No.1251548

Looking for some information on small brushless motors with propellers used in toys/rc
For example, at 1/4 power do they typically produce 1/4 thrust? Or would it be a lot more efficient at lower power

>> No.1251549

>>1251543
Yeah, NAND Flashes are capable of storing massive amounts of data, but you can only access them by blocks, which is not suitable for my application.

I was thinking in using SDRAM for my application, but it would ramp up the costs very much.
I'll explore the PCM memory types. I hope they keep selling them in Digikey or something.

>> No.1251551

>>1251498
>I'm planning to use PWM.
Do you know what you're doing and how to do it with a piezo?

>> No.1251555

>>1251551
I've only driven those little piezo buzzers before.

>> No.1251558

>>1251555
Did the buzzer have built-in electronics (runs on DC) or was it a 'naked' piezo disc?

>> No.1251561

>>1251517
Can you use SPI flash chips, like
http://s.aliexpress.com/Vn22qI3M for example?

>> No.1251565

>>1251558
Just a disc

>> No.1251574

>>1251565
Ok, that's like your tweeter. Half bridge or H bridge if you want max power.

>> No.1251602

Is there any programs that allow you to simulate a breadboard?

I am new to electronics and want to mess around without bending up a bunch of shit and re do a lab I had today in school.

>> No.1251605

Baking new bread. Stand by.

>> No.1251609

>>1251608
>NEW BREAD
>>1251608
>NEW BREAD
>>1251608
>NEW BREAD

>> No.1251619

>>1251549
So use NOR flashes like you originally suggested. They're available in serial and parallel interface versions. Or include the block management shit to your parallel to flash bridge contraption.

>> No.1251695

>>1251561
Looks pretty good. It is indeed a NOR Memory, but if I would need a Parallel to SPI interface if I decide to use it, maybe with a CLPD or an already made chip.

Thanks, I didn't know these chips were so cheap.

>> No.1251835

>>1249620
working on one of these right now.
black lines is just wire.

>> No.1251954

>>1249620
Quick question; I know A is log and B is lin, but what is C?

>> No.1252163

I'm teaching myself and I'm running in to a very basic mental block problem: I don't understand how a circuit works ... and I think I mean "a parallel circuit." I'm read and read and watched and watched and for some reason I just can't get it.

If you take a very basic low pass filter circuit with a resistor and a cap and say a speaker, like:
https://en.wikipedia.org/wiki/Low-pass_filter#/media/File:1st_Order_Lowpass_Filter_RC.svg

I don't "get" what/how the cap works in this. I understand the principal of the resistor& cap, in general, in use as a low pass, but I keep thinking of them as needing to be in series. I don't "get" how the cap impacts the signal when its configured like this ... essentially the cap, resistor and speaker + are all connected together.

Can anyone help break through this very basi idea?

>> No.1252241

>>1252163
the impedance of a capacitor decreases with increases in frequency
the capacitor is a low impedance to high frequency
the capacitor 'shorts out' the high frequency but is high impedance to low frequency so ignores the low frequency

>not a dissertation on filters or caps or impedance, just a 'fundamental' look at it

>> No.1252247
File: 31 KB, 600x600, 250px-1st_Order_Lowpass_Filter_RC.svg.jpg [View same] [iqdb] [saucenao] [google]
1252247

>>1252163
>>1252241

>> No.1252281

>>1252163
They are in series, as far as the input is concerned. (Assuming a load of infinite impedance, for simplicity.)
In the time domain, the capacitor converts current into charge, which is reflected as a voltage difference between its plates. The resistor limits the current and thus the rate of charge accumulation. A faster signal input at the same level, therefore, leaves less charge stored on the capacitor and thus less voltage at the output.
In the frequency domain, it's a voltage divider with a component whose impedance (ac resistance, basically) varies with frequency and one which is fixed.
I bet you would enjoy the CircuitJS app as mentioned in the top post. It shows the current flows and voltage levels in a friendly, graphical manner that might aid your intuition of how this stuff works.

>> No.1252376

I totally understand all of this (I think I do anyway ...) except for this line: "they are in series as far as the input is concerned."

That is, in essence, what I don't understand.

Assuming a speaker over at Vout, the speaker and cap are clearly parallel to the resistor ... hence the black union dot.

I know I'm wrong but I seem to be missing something that lets me understand what right is.

Why is it that "they are in series as far as the input is concerned?"

>> No.1252435

>>1252247
-j159ohms and -j1.59ohms

>> No.1252667
File: 24 KB, 648x864, 250px-1st_Order_Lowpass_Filter_RC.jpg [View same] [iqdb] [saucenao] [google]
1252667

>>1252376
>Why is it that "they are in series as far as the input is concerned?"

>> No.1252845

Yeah, AC. But in DC also?

It's that leg to the Vout between the resistor and cap that's got me confused.

>> No.1252853

>>1252845
>Vout between the resistor and cap
the top schematic and the bottom schematic are electrically identical
>>1252845
>that's got me confused
You're equating stupid with confused - they're different.