/diy/ - Do It Yourself

0 Bad Black
1 Boy Brown
2 Rape Red
3 Our Orange
4 Young Yellow
5 Girl Green
6 But Blue
7 Violeta Violet
8 Give Gray
9 Wellingly White
5% Gold Gold
10% Silver Silver

Multimeter tut:

http://www.youtube.com/watch?v=bF3OyQ3HwfU

EE major/grad here, I have 6 years of design experience and related info and I'm bored, so ask away.

>>699008
FYI most of these books/scientific based electronics mags are good but there are much better resources like:

http://www.allaboutcircuits.com/
hackaday.com
https://learn.adafruit.com/
and of course google.

>>699008
How to choose correct wire size to use?

>>699012
depends on your design really, larger gauges (sizes, small number = thicker) have more ability to conduct larger amounts of power and current. Thinner wires are easier to manage.

On a whole solid core is more for breadboard work while threaded/multicore is for prefboard/prototyping work.

>>699011
opinions on this book? they say its a good book to get into electronics if you dont like mathematics

>>699016
Don't have personal experience with it but a quick read of it (http://iate.oac.uncor.edu/~manuel/libros/ElectroMagnetism/The%20Art%20of%20Electronics%20-%20Horowitz%20&%20Hill.pdf)) It seems very good. This might be me talking, but I'd say get a good grasp of binary and basic boolean logic before doing circuit design, its a lot more fun to make a adder or a calculator then a led light up lol.

>>699019
To add to this, dont start doing arduino and micro work too early before you grasp the fundamentals, its better to take longer and understand how to say interface with a lcd and wire one than to just use a shield for everything.

>>699014
whats a good affordable multi? pic related is too expensive "fuck up".

>>699022
>fluke
you're paying for a color-scheme basically

Check out Daves recommendations for 50 and 100 dollar multimeters.

http://www.eevblog.com/2010/06/04/eevblog-91-50-multimeter-shootout/

http://www.eevblog.com/2010/07/11/eevblog-99-100-multimeter-shootout-extech-amprobe-bk-precision-ideal-uei-uni-t-part-1of2/

I mostly use a extech330 in the field, because its easy to find and easily replaceable. It just werkz. A benchtop multimeter will be the best but they're rather expensive ha.

>>699022
too expensive to "fuck up" i mean. i want one where i wont be scared making mistakes.

>>699025
I'd say (not shilling) I like my extech, if you buy a cheap ass multimeter and fuck it up, it can A: explode or B: electrocute and kill you. For a few dollars more (paging eastwood) you can be protected from your own stupidity and mains voltage lol.

>>699025

if you're in the US, Harbor Freight has a great MM with many features for ~10.

>>699025
The are all fused. Unless you plan on just attaching power sources to random parts of the PCB you shouldn't damage anything. Just be prepared to drop some cash on new fuses.

My other hobby is woodworking. I guess I could buy more materials in this field, right? In woodworking everythig is expensive(table saw, plane, chisel). In this field only the oscilloscope is expensive

>>699033
Try and get a used analog one off of cl or ebay, if you want to tinker that'd be the best, there are also many scopes you can firmware hack to give you $300 worth of features for free, but most beginners will do good with:

Cheap ass scope
Breadboard/wires/power supply
Multimeter
Soldering iron
And wire cutters and the like

Depends what you want to do really

Going to call it a night, if you have any questions reply to this post and I'll answer them tomorrow.

Don't electrocute yourself /diy/

>>699008
Hooking up an LED backwards allows you to use the LED as a light sensor.
How the fuck does that work?

>>699104
When you run current through an LED, charge carriers drop through the bandgap and emit photons as they lose energy. If you instead throw photons into the bandgap, you create charge carriers.

It doesn't have to be backwards, but there are advantages/disadvantages to each topology.

Test pen usage:

Fuse patent from Mr.T
(1/2)

Getting to know origins of electronic components makes me feel better.

Fuse patent from Mr.T
(2/2)

>>699110
Which is to say that if you know how photodiodes work, you know how LEDs work as light sensors.
Ordinary silicon diodes work as light sensors as well, if the chip is visible. This includes 1N4148.

>>699130
To be clear this behavior is cool for things like octocouplers, rotational sensors like tachometers, and even motion tracking using ir LEDs to bounce and receive data.

>>699025
it is difficult, if not impossible, to fuck up a fluke with normal voltages (<50V)

I made a thing once

>>699025
Fluke is love. Fluke is life. Can't go wrong with them.
Klein makes a great cheapo one that is safe and has every fucking function ever on it and a fucking flashlight.
>I wouldn't get a harbor freight branded widowmaker.

>>699190
>octocouplers
Heh, I know a guy who says this.

>>699027
EEVblog destructively testing multimeters:
https://www.youtube.com/watch?v=M-FZP1U2dkM

I also use the Extech330, it should easily handle this kind of abuse without exploding.

>>699297
Sorry but I'm cracking up imaging some 12 year old on /diy/ sexually abusing a multimeter and then it exploding.

"Oni chan what are we going to do on the breadboard" =3 ohmp

>>699022
>whats a good affordable multi? pic related is too expensive "fuck up".
all the flukes are too expensive for hobby use IMO, the cheapest basic fluke with only a few features is like $80, the nice ones are $200+ and there's nice China MMs around for $20 that work just fine

(keep in mind that no NORMAL multimeter is made for measuring more than about 500-600 volts! if you try to measure the voltage output of a cheap stun {that might be 10kV} gun you'll probably kill any voltmeter)

it kinda depends on if you want to do analog electronics or digital stuff... analog would be things like radio transmitters/receivers and audio amps.

if you want mostly digital stuff then a good soldering station helps a lot because the tips will be pointier and soldering .1" connectors is a lot easier. if you want to goof around with arduinos or other similar boards thats cool but there's not really a lot of 'designing' involved as its so easy. it's just pulldown/pullup resistors and connecting logic lines (which is not a bad thing! making something that works is always nice)

an oscilloscope and a function generator are great to have if you want to build audio stuff, but they're not much use if you are doing arduino/digital stuff....

for tube audio there are odd creatures like the vacuum-tube voltmeter (measures accurately up to 1000-1500 volts) and LCR meters (if you are making your own audio transformers) but even so it is possible to get by without those things. most audio tubes are operated at 300-450 volts, it's only RF transmitters that get up into the thousands of volts

>>698995
>Where to buy pieces?
eBay
>How do I into pcb?
Eagle or gEDA and any cheap offshore fab place like batch PCB, Silver Circuits, Custom PCB, etc
>How do I solder?
Soldering iron.

>>699022
I use extech portables and get old Fluke bench MMs for high-precision bench use. They can be had calibrated for not too much because the fluorescent displays go dim after 30 years of being on 24/7.
Consider an LCR bridge meter and a cheap scope as well.

>>699033
Good analog bench scopes, once the best available: Tek 22xx and 24xx
A not terribly precise, but super-convenient pocket scope: DSO201 ($50 new) or 203 ($80 new). They can't compare to the old Teks, but I end up using them way more since they're so damned portable.

breadboards are nice too.

>>699562

Whats a good electronic simulator e.g. virtual breadboard would you recommend and why?
>inb4 google
I want to know what /diy/ recommends and not some postcount-whoring ego-boosting e-penis forumfags have to say.

>>699573
>Whats a good electronic simulator e.g. virtual breadboard would you recommend and why?
I don't use them. Why would I? I can build anything I want on a real breadboard faster than I can click it into place in a computer program's UI. Not to mention the real circuit is real, the virtual circuit is always at best approximate behavior.

>>699573
LTspice

>>699575
>bob pease is posting to /diy/ from the grave
You might not use them, but there are perfectly good reasons to run sims. So you can test logic or circuitry before buying parts or ordering a pcb. Breadboards have their own issues like stray inductance and capacitance. And so you don't have to get out of bed to play with circuitry.

>>699639
>You might not use them, but there are perfectly good reasons to run sims. So you can test logic or circuitry before buying parts or ordering a pcb. Breadboards have their own issues like stray inductance and capacitance. And so you don't have to get out of bed to play with circuitry.
Sure, but we're not exactly talking about any of that here. The complexity of a good sim is beyond OP, and an easy/toy sim is going to be like playing guitar hero.

>>699618
Seconding this

>>699640
[tip of the hat at the Bob Pease mention. I knew him at MIT many years ago.]

>>699642
I read about him and I have one of his books. He sounded like a brilliant, rad guy with a great sense of humor.

>>699618
thanks anon! i'm loving this thing

Beginner related curiosity question:

why do some power companies keep shutting off power supply even on occasional rains? its not even a fucking storm! they made a power supply corporation and yet too "bankrupt" they decide to limit voltage supply? electricity is more than a century and they should have enough technology for whatever alibi they come up with. they be shitting me. brb learning diy solar + wind. electric compaies can go fuck themselves soon. monopoly my ass.

>>699708
what country anon, thats really wierd.

okay, this thread kinda got me pumped to try my hand at electronics, so thanks for that. I remembered just as the excitement set in however, that I'm colorblind, and that's why I never into electronics in the first place. are there any trade electronics engineers here who are colorblind? What methods do you use to keep everything sorted? I tried looking a couple years back for colorblind friendly wiring, but no such luck.

>>699708
They have been charging x for service to maintain the network, pay pensions, take profits, etc..

They don't do #1. So then they raise rates and say 'no really we are going to start doing infrastructure repair'

Then they look at all that new money that just rolled in and they say 'fuckit' and take it all for profit again.

This has been happening for 40+ years. The power network is so much worse now than it used to be. This wasn't a problem even 20 years ago. shit worked.

The best thing that can happen is a fire will come through and burn all the poles down.

>>700040
Hrm, what colors? You can just use white and black wires for pos and negative, anyway most sim softwares are only 2 colors as are most oscilloscopes, so naturally its easy to see things even if you are colorblind.

The only problem is for resistors, but a good labeling system and a multimeter will make things easy. Almost every other part requires no color, only that you can read.

>>700087
it's mostly working with resistors that I was worried about, but also when putting something together I'd like to be able to open it back up and clearly see what I had going on, that also happened to be something the guy behind me also understood. idk, the maximum extent of electronics I deadly with was rewiring a couple trailers. the Pollack style had similar colors and I ended up cutting every line to check that I was connecting to the right lines.

>>699011
>hackaday.com
how is this a good learning resource? It's just showcases of hacks it's not like a teaching course or something.

>>700483
Well most links will have a how to, and there are 10 years of neat projects archived. If you have a idea its probably on hackaday

>>698995
allaboutcircuits dot com

Lately I got into building some simple arduino stuff and discovered my aspie side when I began trying to lay out stuff on breadboard PCBs with hookup wire and bus wire....

what lower-cost software is there to design circuit boards that is bigger than Eagle? I would want maybe 5 x 10 inches at the most, and would want to be able to have these PCBs made somewhere.

Eagle gets talked about a lot but it has ridiculously small area limits unless you pay or steal the full version, or you do something silly like use edge connectors/right-angle pin headers to stick multiple boards together.

thanks to OP, and any other contributors

>>700750

Personally, I use DipTrace.

The issue with that is that you're limited to 300 pins/2 signal layers with the free version. although you can get a free non-profit license upgrade to 500 pins as a hobbyist.

They also offer a full-function 30-day trial version which can be abused, of course.

I'm just getting into electronics. i have a couple of books and have built a tone generator from a kit along with a small amp, but I don't really feel like either of the kits really helped me learn anything other than how to read the instructions of where the parts go and how to solder. these were basic kits but nothing was explained like I thought it might be, for example what all the resistors and capacitors do in the chain they are in or even what the chips do?
Have I jumped forward too much and missed all the this is how you use a switch to turn a light bulb on/off, or are these kits just shitty? they were in the learning electronics section of maplins.
Also my main interest for learning electronics is to eventually be able to make sound generators and effects units, maybe even basic synths. I'm very much interested in Reverbs, Delays and Echos.
What would be a good resource for learning about electronics for sound.
I have the book that is being posted below and also a much more serious looking book called A practical introduction to electronic circuits.

>>700750
kicad - free and open source, runs on Linux and Windows.

>>700761
Read this: http://www.ve7na.ca/cms/system/files/Lesson-5%20Electoninc%20Theory_0.pdf

Then read this: http://www.ve7na.ca/cms/system/files/Lesson-4%20Circuit%20Components_0.pdf


It's weighted towards radio circuits, but these are very (VERY) similar to audio circuits and often the two overlap. These were useful for me when I was trying to learn how to build circuits, and others have found them enlightening. Radio clubs can actually be a great source for guidance; there are always a few old guys and/or engineers hanging around who have built their own rigs and are usually willing to help out.

>>700779
Seconding Kicad

>>698998
>>698999
>>699002
>>699003
what is the source of that? looks awesome

To any Anon that works with electronics
What are the tools required to start a "test lab"?

I mean, I see multimeters, those power sources (I don't know what they are or do), or cable cutters, etc.

What do I need to build a lab just to play and learn some electronic stuff?

>>701138
Make: Electronics (Learning by Discovery)
by Charles Platt. Or at least it looks like it.

>>701141
"third hand"

>>701141
'fill em til you're satisfied

>>701150
4got pic

>>701149
>>701150
o-ok thanks

>>701154
Nice

>>701141

I'll assume by "test lab" you mean "electronic hobbyist's lair".

In which case, you're going to need a fair bit of crap.

I've got all the handyman's basics (strippers, side-nips, pliers, solder, soldering iron, third/helping hand, shrink wrap, various wires and cables, etc) and then actual electronics hardware. Think breadboards/jumpers, soldering/hot air station, PCB stuff, etc. Currently missing a benchtop power supply and oscilloscope (and it pains me that I do), which can run you a fair bit of cash. Beyond that, you're pretty much just picking stuff up as you go and filling up part drawers.

>>700846
Thank you looks very helpful.

>>700761
O.k I'm about to try and make a DAM Meathead this evening as my first Pedal project.
Now the stripboard layout shows all the components in position on the board and I'm about to drill the holes in the stripboard, but as I'm thinking about this I'm looking at the stripboard with the copper strips facing up as in the diagram and am a little confused as it also shows the components that i would have thought would be on the other side. Is this right? So do I just copy exactly as it is drawn as if the stripboard is transparent or do I flip the board over and copy the drawing layout as it is? Fuck i'm confused already!

pic related

>>701348
You're looking it from the component side. The copper strips just "show through" in that pic.

>>698995
The MAKE books at RadioShark are a bit pricey, but they will teach you a lot. I cant remember the name, but this is a page from it.>>698998

>>699001
That's a hell of a way to remember.

>>701360
Thank you, Ive drilled the holes in the wrong place then.

>>701164
thanks

>>701154
Love that custom bench board above the desk. Very nice.

>>701348
I'm nearly there with soldering the components. I think I'm learning a bit about these parts hopefully if I've identified them all properly?
These 3 legged fellas are giving me a bit off grief though. How do I identify which legs are EB&C? Mine look very similar with hardly any markings apart from one has 2 bent outer legs? Help pls.

Pic related it's how I've interpreted the strip board drawing!

>>701402
>How do I identify which legs are EB&C?
you look it up on the data sheet for the specific part number. It's not consistent across part numbers or packages.

>>701403
Thanks, been looking at this but there seems to a lot of different makes and shapes of 2N3904 NPN Transistor. Will all the different makes be consistent in model number?

>>699394
Have to admit I lol'd

>>698995
Check out a guy called Forest Mimms, wrote some awesome intro to electronics books...grew up with that guy.

>>701402
Do you have the exact same components as your layout pic specifies? If yes, just install them as shown. If not, download the datasheet. Be careful with top/bottom view pics in datasheets.

>>701414
its all part of a kit so yes, I'd hope.

So just place them with the flat side like in diagram and that should be right?

>>701405
In the case of the 2N3904 in a TO-92 package (what's in your pic) it will always be the same. It gets trickier for stuff like the BS250 that actually has a suffix denoting what order the pins are in (like the BS250KL or BS250P)

>>701410
Seconding and thirding Forest Mimms. I cut my teeth on his RS 'Engineer's Notebook' series in the late 70s too. They're just as good now.

>>701420
thanks.

>>701348
I'm presuming the input will be a 1/4" plug as its a guitar pedal, I'm going to swap the 9v plug for a 9v battery connector. I'm guessing the output will be another 1/4" plug so I can take the signal to my amp?
Could someone pls explain where all these tails of wires go for example the grounds, LED?
I'd think the 9v red lead will be coming from the + on the battery, would the ground below it also be the - from battery?

>>701402
whats that pcb called?
Also how did the diagram maker determine the kind of resistor to use? Where did he start about this?

>>699573
I use NI Multisim

>>701522
There is no PCB it's just a plain stripboard.

I have no idea how the designer determined what kind of resistors to use, I'm guessing as it's a meathead clone he's either opened one up and copied the components or has worked it out by being clever.

>>701522
Pic related seems to be the answer. Any experts confirm?

>>701756

More or less.

The LED's forward voltage should be taken into account. It will drop a certain voltage across its terminals (since it's a diode), so it shouldn't be 9V, it should be 9V - Vf.

Although usually you just fudge it and grab the nearest 1k because it doesn't really matter (for plain-old indication LEDs, anyway) what you use as long as you're not exceeding the LED's continuous current rating.

Is it just me or are OTAs really hard to find?

>>701756
totally wrong
voltages add in series and are the same in parallel. current does the opposite. kirchoffs laws check them out.

>>701762
this is what you do

9 - vf = vr (resistor voltage drop)
r = vr/i (i is led operating current)
then important
p = vr*i = power dissapated by resistor in watts. normal resistor is 1/4watt rated, so anything above 0.25 could in theory destroy the resistor and start a fire.
e.g. if you have two resistors in parallel say and you want to use one resistor:
voltage across parallel led is 2v (the same as one) current through the pair is 0.04A (double current for parallel)
r = (9-2) / 0.04 = 175ohm
p = 7*0.04 = 0.28watts. 1/4 watt resistor will self destruct in theory (in practice its probably fine)

but anyway don't share a resistor between tow leds in parallel like that its bad practice, just an example

Hey guys!
I know very, very very little about electronics and electricity and stuff, but i want to make a little contraption- a motor that can spin both ways, and I don't want to buy any fancy motors, arduinos, or whatever complicated and expensive shit you guys are using.
If I recall correctly from high school it's just a matter of changing the flow, right?
My first idea was just to hook it up to two separate batteries, and just use a swich of some sort to alternate between the two directions. But it seems pretty retarded.
So, is a nice and simple way to do this? Without a buying a lot, with stuff that I might have at hand (very basic stuff)? Is there a trick to alternate the current or something?

>>701875

you just need a single double-pole, double-throw switch, aka a 6-pin switch.

>>701902
Lol, I just googled the same fucking pic to post.

>>701902
K, thanks a lot!
Seems simple enough

>>701864
How to get the Vf value?

>>702026
vf is forward voltage of the led
i.e, the voltage used by the led
voltages add in a series circuit.
battery is in parallel with the two components which are in series. the voltage over the series components must sum to give the battery voltage.
so 9v = vf + vr or vf = 9v - vr

>>702026
From LED datasheet. It's usually around 2...3V, depending on color and type.

Just sharing this gem that I found. With actual moving current! Its also downloadable as offline version

>>699573
Multisim is pretty good and easy to use

>>703014
That's neat and all but current flow simulation tends to get confusing on large scale digital electronics. Watching the current flow can detract from the purpose of a circuit or make it more complex than it really is.

It's great if you're first learning electronics though. I just wouldn't use it for large scale projects.

I also made a threat out of this, But I better post it here tho

So I have to make a circuit for school and i have to receive an rs232 signal from a Zulu Modem M868, the signal is 3.3Volt

I want to send this signal to an ftdi chip to make an usb signal out of it.
But I also want to connect to to an max232 to get boost it to 8volts so I can connect it to a serial connector.

I'm guessing it's not smart to connect them both at the same time because if someone were to use both interfaces at the same time they would interfere with each other?

How do i make a switch to use only one of those two?
-Do I connect RX/TX/CTS/RTS to jumpers to switch between them.
-Do I connect vcc of both to jumpers and just poweroff one of the two controllers? (Is that even legal)

Pic related breakout board for the ZULU modem M868, my first pcb evha.

ok, this is a more involved question, and my background is copying schematics or troubleshooting auto electrical.

I've been soldering for a few years and i built a couple clone stomp boxes, but this idea requires a custom diagram.

my intent is to install leds in my guitar speaker cabinets that respond to what I'm playing and the volume(increase/decrease in brightness with volume, no light with no signal).

the big thing is that I'm using tube heads, which don't allow much variance in impedance. i also use clean sounds a lot so installing leds(which create clipping which is not ideal). I've been researching and thinking and have come up with some ideas.

1. a/b/y box at the end of my signal chain before the preamp with one of the split signals feeding to a jack on the amp that completes the circuit when I'm playing. this is really basic but i doubt it'll allow variances in brightness. also i use a stereo rig and will then be splitting my signal 4 ways.

2. use a microphone as a trigger. actually found a thread on this and it included a way to make brightness vary, and an idea about filtering frequencies to trigger certain leds when different octaves are hit. alas, it was for subs in a car, I will be playing with my amps next to a drummer who hits hard and a Mic will pic it up. might still be cool, but he can get his own cheesy led gear.

3. wire the leds either after the speakers or in parallel and hope it doesn't wreck my sound or my amp. obviously not a good plan because the thorough misunderstanding of impedance, current flow, and of planning itself


you guys got any ideas?

>>703248
actually, could I use a relay to complete the circuit without interfering with the signal chain?

>>703248
Optoisolators?

>>703939
still diodes.
Use anything with a FET input stage as a buffer. Any number of opamps can peel the signal off with no trouble.

I screwed up.

Was pulling this EEPROM out of its socket and the Vcc pin literally fell off.

Is there any way to fix this on a whim before I go insane?

>>704068
Solder a new lead on it.

>>704068
yeah easy, just use a small piece of wire and solder it to the tab

I'm new to soldering and just bought a pencil-fine tip soldering iron.

It's supposed to be a low heat iron, but the end of the tip doesn't get hot enough to melt 60/40 solder. I have to turn it on it's side to liquify the solder then I can't get it to run down to the end of the tip; defeating the entire point of the fine tip.

Is it possible this is because the tip is poorly coated or because of some other defect with the iron? Or is there something else I should know?

>>704184
>I can't get it to run down to the end of the tip
That's not how you solder. It's not like solder is paint and the iron is a brush. You put the tip of the iron to where the component meets the PCB, heat them both up for half a second, then (with the iron still making contact) apply a little solder.

>>704186
I know that much, but the tip doesn't transfer enough heat for me to do that in the first place.

Applying it directly to the middle of the tip is the only way I can get the solder to liquify but I need to use the end of the tip for what I'm doing. I only mentioned that in case it indicated that something could be wrong with the tip's coating.

>>704188
did you do the "tinning"?

>>704189
No I didn't. I guess that was something I didn't know about. Is that necessary for using a new iron or is it just for maintaining?

>>704068
Put it on a socket, solder it permanently to the socket. It's bit easier that way.
Or just solder a wire to it like the others suggested.

>>704191
It's basic maintenance for the tip. The shittier iron you have, the more often you need to do it. New tips are pretinned.

>>698998
>tfw learning from this book.

Friendly advice, ignore what he says about what soldering irons to buy and invest in a good station with built-in temperature adjustment. Weller is probably the best brand to ho for.

>>704251
I have to agree I have gone through tons of the cheap radio shack. Then a got a weller and so far it has lasted something like 5-6 years compared to a few months.

any soldering iron between 40 and 15w will do. cheap ones even. doesnt matter.

first, OP doesnt need to do ROHS
second, OP wont be starting with temperature sensitive or connection quality sensitive circuits, he'll be breadboarding for weeks before he graduates to a soldering iron anyway. then, it'll be a few transistors that he just needs to not fry. which can be solved by just clamping an aligator clip or similar heatsink to the lead between the chip and the pcb hes soldering it to to stop it from burning out.

I only got a temperature controlled hot air station/soldering iron because I started actually needing to do QFPs

for everything else, you just melt the solder and stop heating it when its molten

Hey guys, I am wanting to do ram upgrade mod on one of my tp link 703n routers. But I haven't done it since the ram pins are so close to eachother and I am under the impression each solder point can't bridge to another pin? I have shakey hands and seems like this would be impossible for me.

>>704373
>and I am under the impression each solder point can't bridge to another pin?
yea, usually you can't let that happen ;)

it would help if you could post a pic of what you want to change.

most manufactured electronic stuff now is usually SMD which is difficult to do with only a soldering iron--especially a cheap iron with a fat tip
http://en.wikipedia.org/wiki/Surface-mount_technology
there are people who work with this stuff using only a good soldering iron (that means,,,,, a soldering iron with a skinny tip and enough power to heat it up HOT)

>>704386
>that means,,,,, a soldering iron with a skinny tip
Actually, for most surface-mount no.

>>704068
the best way would actually be to sold it into a dip socket. That way you don't risk making the pin too large or small.

This thread needs a bit of a kickstart.

Does anyone have any schematics of projects they're working on? Pic related, my dad just bought me this kit. It's pretty basic, but it's neat.

>>704727

Building a robot to play a hammered dulcimer. This is actually the schematic for >>700752.


This would have taken waaaaay less time if I wasn't so god damn cheap. An ATtiny84 isn't exactly the most appropriate chip for this, although it works fine.

Hey electronics general.

I'm gonna be making an LC meter soon and it will involve programming a PIC.

Could someone do a rough summary of the process and things I may require?

Thanks guys.

>>704732
Oh and this is the schematic I'm going to be following.

I know shit about electronics, but I cam up with an idea the other day for a circuit that uses diodes to allow either end of the circuit to be used as the positive/negative interchangeably. Related, where's a decent website to sketch/test simple circuits?

>>704736
Electronics Workbench is a handy piece of software that might suit your needs.

>>704736
http://www.falstad.com/circuit/

>>704732
>>704734
You need a programmer. You install it, connect the programming cable (power/ground/reset/rb6/rb7, see datasheets), open the hex file (provided by the author of the circuit) and hit the program button. Or if your programmer has a socket, you can put the chip in it, instead of using the ICSP cable. That's it generally, details depend on your programmer. You can make the programmer by yourself or buy it.
It would be interesting to hear how well that LC meter works.

Also, lol tripfaggotry on /diy/.

>>704736
Something like this?

>>704771
Sounds simple enough.. I'll be sure to post my progress.

Like every cool general, we need a /name/.
It's gotta be short, make sense, and describe the general.

How does /ohm/ sound?

>>704783
We should also keep count then.

We might even get to a 3rd thread by December.

>>704788
We already have our retarded resident tripfag!

>>704788
Sounds good. After my exam I'll put together a decent OP for the next threads. There's a lot of new electronic enthusiasts and it'd be nice if the OP gave them some direction.

I know the bump limit is different on slower boards. is it 300 here?

>>704804
>I know the bump limit is different on slower boards. is it 300 here?
Yes
And threads can live up to a week or more after hitting the cap.

>>704805
I'm going to start posting projects I'm working on and maybe academic resources I'm getting through my university. I'm hoping others will do the same so we can have an active general for electronics. I'm pretty jealous of /g/'s daily programming thread and wish this general was as active.

Maybe we can turn a few more people on to the hobby.

>>704809
People who already know electronics tend to be assholes for some reason.
That's a big part of many people not being interested in it.

>>704811
I feel like once this general gets some momentum it'll be (maybe) the most active thread on /diy/. There's a lot of people who are interested in it but don't know where to start.

Well I'm still sorting out my education, going into electronics so I'll have a lot of projects I'll be doing, including the LC meter and I'll try to document and post my steps to keep the thread up.
Might even start drawing up the PCB today so I could post a bit of that.

>>704791
Well technically I'm retarded everywhere but I'll make my presence here known.

How tedious would it be to make a 4 bit ALU with an IC? I kind of want to make a diy simple processor.

>>704835
without an ic***
I want to make it from basic components.

>>704835
Oh look, another retard. (Yeah, I'm wasting my time on a similar project.)

To get an idea, you could take a look on 74LS181's internal schematic. Replace every gate with your own transistor equivalent in your mind.
Or you could Google a transistor full adder schematic and imagine putting 4 of those together, with a 4 x 2 input nand (or nor) and a multiplexer. That would be a pretty minimal ALU.
Or you could implement the ALU as a diode matrix ROM. See how big ROM you need and imagine that with the X/Y decoders (which can also be diode matrix ROMs).

Tl;dr. It's going to be very tedious, particularly when you count in all the other junk you'll need for a complete processor.

>>704835
I'll be costly.

Go buy any cheap CPLD and design yourself at logic level.
It's cheaper and you can reprogrammed it to do other stuff once you're bored with your *processor*

hi, newb here, what's a simple way to filter an analog DC signal looking like a) so it looks like b)
the signal is about 2,5 ms wide and from min to max is about 2 Volt

the goal is to feed that signal to the analog comparator in my ATmega, but as it is now a single signal causes a lot of interrupts

hi, newb here, what's a simple way to filter an analog DC signal looking like a) so it looks like b)
the signal is about 2,5 ms wide and from min to max is about 2 Volt

the goal is to feed that signal to the analog comparator in my ATmega, but as it is now a single signal causes a lot of interrupts

>>704859
You'd need to rectify it first to achieve what your pic shows. Are you really sure you can't handle this with software?

>>704849
The diode matrix actually sounds really fun.

>>704835
>>704836

I kind of intend to do the same, but only once my pick and place is finished.

How hard it's going to be depends on what all you want the ALU to do. If all you want is the basic add/subtract/logic functions, that's one thing. If you want to add multiplication, division, and whatever else, that's a whole other thing. In either event, routing it is going to be a bastard.

It would also be fairly expensive to use THT parts (disregard completely the issue of actually soldering those in). The only reason I'm even considering doing it is that a pick and place would make it practical to use SMD FETs, which can be had for about $0.015 each from China. Still, when you need a thousand or three, it ends up much more expensive than a chip.

>>704836
>without an ic***
>I want to make it from basic components.
in the VERY early days of home computers--when all you got was a circuit board that you had to find a power supply, keyboard and TV to use with,,,, and all it could do was show text on a TV screen--what they used for a lot of the logic was called "7400-series" or "74xx" chips. these were DIP packages with individual logic gates in them, or simple arrangements of logic gates to connect in more complicated arrangements.
http://en.wikipedia.org/wiki/List_of_7400_series_integrated_circuits

jameco for one place sells a variety: go there and in the "product type" menu, click on [Logic] and then [TTL]

the 7400 series is basically a generic design now, a number of manufacturers make equivalent chips, in different packages now

>>704859
Remove the DC component with a high pass filter (like a capacitor), then use a rectifier, then a low pass filter.

You can do all of these steps with software too.

>>704835
Not too terrible. You can do it with a large breadboard.

Check out this, an entire computer built only with NAND gates. It's not even that large.
http://blog.kevtris.org/?p=62

>>699014
For wires that should be thick and also flexible, I'd also check out silicone isolated wiring. It's pretty expensive, but you can twist and bend 16AWG wiring like it's 30AWG. It was a godsend for me when wiring my power anp's supply and speaker lines. Obviously the strands have to be very thin to allow for this, but as far as I know that's the case with most silicone wiring.

>>699011
>adafruit.com
that's from Lady Ada, right? I've seen her name mentioned in the cDc textfiles back then. I've read she made the epic RF-Jammer inside the cigarette box thing. Man I wish I'm that advanced already. Oh well back to studying resistors for now.

>>704980
Epic shiggy

>>703943
>>703939
I figured it out! i realized i have a line out on the head for direct input into a mixer, it sounds terrible so I'll never use it. it outputs higher voltage than the cable directly from the guitar, and much less than the peak output at the speakers(around 350vac), and it in no way affects the tone.

the only issue now is that they start working around the volume being set at 6, and don't start working well til it's around 8. that's really fucking loud, but not really a problem. i could probably throw a signal booster in there, or hook a mixer up in the middle and boost it that way.

now, any advice on hooking up several leds? probably 36 to 44 in a single array. I would imagine to make it work with some standard power supply it'll involve some wizardry of using series and parallel circuits. Ideally I could connect them all in series with a 9 volt power supply, i really don't think that's possible at all though, at least without the last leds in the circuit being incredibly dim if lit at all.

power supply isn't to much of an issue. i want it to use a coaxial m size barrel jack, but i could throw that on any power supply i get from the thrift store.

I'm thinking I could do something a little ghetto and run a single wire for hot from the pz, strip it at the point where i want the led, and solder the resistor directly to the wire, then use a metal strip for grounding the leds that returns to the ps. is that feasible?

>>704974
>not entirely 2-input NANDs
>bit-serial arithmetic
It's almost like he didn't hate his life.

>>699435
Breadboards are wonderful! :)

>>705198
*drools

>>699001
my dad grew up in white majority rhodesia. then it was
Black - black
Bastards
Rape
Our
Young
Girls
But-shares 'U' with blUe
Violet
Gives
Willingly

this way you can remember easily which is black and which is blue

2nd year electronic engineerfag here, you might like to watch the power supply I built. It's quite neat I think, It has double output using two LM317, 1.5 amps each. The box is 17 * 12.5 * 4.5 Cm, so its quite small.

https://www.youtube.com/watch?v=zudFl4c_SyY

>>705312

This are the insides. The 230V switch has been already insulated.

I was thinking the other day. Why should i go low level(c with an atmega chip) and not just an arduino? The only negative is the price right? and i dont think i could make something better fhen the arduino language.

>>701748
Yo dawg, heard you like breadboards...

>>705348

Arduino should be used to learn about microcontrollers programming, at least that's how I see it.

You can get into more advanced AVR or PIC microcontrollers once you have a solid base with arduuino.

>>705348
>embedded system
>c
>low level

you cannot have all of these anon you are being greedy.
program in asm and unlock the great mysteries of the universe

>>705348
>Why should i go low level(c with an atmega chip) and not just an arduino?

They are literally the same thing. Arduino is just a bunch of C macros and a bootloader.

Also:

>low-level
>not ASM

I shiggy diggy.

>>705450
>Arduino is just a bunch of C macros and a bootloader.

To clarify:

Pretty much the entire point of Arduino is to hide all the nitty gritty of how the various registers in Atmel chips work behind pre-baked functions, and provide a bootloader so that you don't need a dedicated programmer for them (although, since the Arduino boards, even the knockoffs, are more expensive than a USBasp, I never saw the point of that).

The other advantage is the libraries available for it, which may or may not be useful depending on exactly what you're doing.

hey guys, really glad to see this general thread thing happening, awesome.

Im building a nuka cola lamp for my girlfriend, using this instructable.

http://www.instructables.com/id/Nuka-Cola-Quantum-and-Nuclear-Reactor-Display-Stan/

I stole some scrap steel pipe from work so i decided to use that for the base rather than PVC, here arises my question. A switch at the base of the pipe (the three pronged fellow), will sit very close to the steel.

As steel is a conductor will i kill her if turns it on while it happens to be touching it? how do i insulate a switch you know? ill post a pic

>>705481
the blown up portion represents the inside of the lamp

>>705481
> will i kill her if turns it on while it happens to be touching it?

Yes. You probably want to find a different switch. You should also ground the metal base. That way if a hot wire touches it you'll trip a breaker instead of creating a death trap.

>>700752
>DatPWR

>>705519
I have a momentary switch that i didnt end up using for the original design. i could use that.

is there really no other way around it? insulate it some how?

how do i ground the base

>>705527
>how do i ground the base
Use a three wire plug. The large circular plug goes to ground. Connect the wire running from it to the base. It's usually green. Attach it properly with a nut and bolt, not glue and tape.

>>705481
is there a way to light an led in the bottle with induction? that would be cool to try out

>>705531
Yes, but you'll be losing a lot of power since induction is much less efficient than a wire.

Start with a circuit like this designed to run LEDs from mains. Next build a 1:1 air gap transformer to go between mains and the circuit. An air core transformer is two coils next to each other with no ferrite core like a normal transformer.

>>705446
>>705450
C allows direct access to the peripheral registers, which is the lowest level for the peripherals. Pretty much every C compiler also supports inline asm, if you need that level of control. The exact details of the core tend to be less important than the peripherals, though.

Well, the choice is yours.

>>705312

That's quite nice, analog displays rock!

>>705554
the main difference you get is the orgasmic feeling of controlling something in practically its own language. you are at one with the processor.
you will never know true beauty until you have written a nested nop delay loop which accounts for branching and call/return times. you will never appreciate elegance until you purposefully start an indirect register at a certain location in memory so you can check a bit change in address to know when you are finished without a separate counter variable
you will struggle to feel as inadequate as debugging a 4-byte float square root subroutine on an 8-bit architecture.

What is this "10n" capacitor supposed to be? It should be something like "uF" right? How should I buy this?

>Hey sexy, I need 2 pieces of "10n" capacitors
>Salesgirl: wtf?

>>705617
10 nano Farad caps.
You can buy them.. I was using a 555 timer for an IR barrier and I needed one myself.

>>705619
Thanks. I learned new stuff.

>>705617

10 nano are 0.01uF, but you just say 10 nanoFarad ceramic capacitors for the sake of convenience.

Capacitors below 1uF are often ceramic, the chances are the shopkeeper will handle you pic related.

The code for 10 nano is 103, 100 nano is 104, 1 nano is 102 and so forth...

Many times I've been given the wrong ones because they end mixing them and they can't read the number afterwards, so if you ask for a 10 nano capacitor look for the number 103.

>>705617
>Salesgirl: Would you like that in ceramic, monolithic ceramic, polyester, mkt or polystyrene?
>OP: Errrrr
>Salesgirl: Oh and what voltage rating?
>OP: er well it works on 6 volts. Do you have them in 6 volts?
>Salesgirl:Laughs to her self.

>>705622
They said they only have it in mylar form. Does it make any difference?

>>705627
I hope that was meant to be a joke.
Those are around 100 times more expensive than the part you need. But yeah, they would work.

>>705481
>>705519
>>705527

guys ive already drilled all the holes in the base, is there really no other option. cant i use some kind of plastic plug to insulate the switch.

anything, plz

>>705536

Is AC really that easy? Diamond rectifier a couple caps and a resistor? Obviously all those components need to tolerate ~240v (or your mains voltage of choice) but damn that's simple. Any idea what you'd want to add to make sure you don't burn your house down? (Out of curiosity, I have and will continue to avoid AC like the plague until I'm very comfortable)

>>705645
Kind of, without some capacitors and diodes to smooth out the signal, it'll be very noisy but yeah that's essentially it.

>>705645
If you think about AC as a sine wave from -V to +V then all the rectifier is doing is cutting off the negative parts. You're left with half a wave from 0 to +V. It's really bumpy, as you might imagine, and not ideal but it's technically DC. For most applications you'd need to smooth it out and this is usually done with capacitors diodes and I've seen some circuits use an op-amp. usually it has a step down transformer with it since most projects don't use 120V. Making your own power supply isn't that hard and is usually a lot of early electronic enthusiasts' first real project.

>>705627

The voltage is a lot higher than what you need, this can lead to energy losses in some cases, it's like to use a football stadium to play chess, but it should work just fine.

>>699432
>>699035
Have been going a long time without a scope. Repair and build valve amplifiers.

I'm worried my testing voltages will be too high for a pocket scope and most old used scopes look to be in questionable condition. Don't want to buy myself a new project.

Got some quick recommendations?

Does anyone know any sites with info on using an arduino to control a brushless motor that is NOT using an RC ESC?

I need a motor about as big as a 3/8" drill motor, maybe 300w.
I have a use that needs a precision motor but with a higher top speed than stepper motors can (easily) provide. From 0 to ~1000 RPMs, and controllable by individual steps.
There are good DC brushed 12v motors around, but I wonder how long the brushes would last in my use.
There is lots of good RC brushless motors around, but I've found no DIY circuits for driving them so far. Only industrial servos with integral controllers & network device, for $500++.

I could make my own optical encoder for this use. I figure it would have 1 zero-position sensor and another sensor with 15 spots per rotation? I am assuming here that a RC motor has three phases per 1 revolution.

The ESCs used for RC vehicles include built-in protections (that can't be bypassed) and may have operating limitations not apparent... I'd much rather just have 1 arduino running the motor alone, so I can get it to operate however I need and call the speeds and operation however I want from the main arduino.

Idea #1: if you ran 1 DC motor driver, you could use 3 power transistors to route the driver power to any of the 3 phases you wanted. You could have overlapping phases but there would be only 1 waveform....
Idea #2: if you ran 3 DC motor drivers, you could run each one to one phase and set up the phases to fire however you wanted (you could run the 3 DC drivers to achieve any type of waveform and overlap you wanted). I think this would run smoothest at low RPMs, which would be important to me.

dumb question: if i'm trying to charge a 120 v deep cell marine battery with a 24v dc motor does current matter at all? how does voltage and current come into play in terms of charging battery cells?

>>705661
>all the rectifier is doing is cutting off the negative parts

The circuit shows a bridge rectifier, so it's reversing the negative half of the waveform, not just cutting it off.

>>705742
(ansering my own post)
I did find this page, which goes into quite a bit:
http://elabz.com/bldc-motor-with-arduino-circuit-and-software/

turns out normally you cant have overlapping phases because the three armature windings are wired end-to-end, in either a delta or a Y configuration.... but re-wiring the motor is possible. Most seem to be 12-pole with 9 poles on the rotor.... :|

>>705782
>120 v deep cell marine battery
You sure it's not a 12v battery? That's what most deep cell marine batteries are.

> how does voltage and current come into play in terms of charging battery cells?
Vb is the present voltage of your battery.
Vc is the voltage of your charger.
Rb is the internal resistance of the battery, plus any resistance from wires going from the charger to it.

I = (Vc-Vb) / R

Vb goes up the more charged your battery is, so the current goes down. Chargers usually have a maximum output current, and will reduce Vc to keep it below this level. I can't really predict how your motor is going to behave without knowing more about it.

Alright guys. Here's my attempt and an OP for future electronics generals. Tell me what you think and what I should add:

Electronics General - /ohm/

>I'm new to electronics, where do I get started?

There are several good books that are commonly recommended for beginners and those wanting to learn more. There are also plenty of good Youtube channels that teach about the basics as well as advanced concepts. The best way to get involved in electronics is just to make stuff. Don't be afraid to get your hands dirty. Take something apart or build something you find cool on one of the many electronics websites.

>What books are there?

Beginner:

Getting Started in Electronics by Forrest Mims III
Make: Electronics by Charles Platt
How to Diagnose and Fix Everything Electronic by Michael Jay Greier

Intermediate:

All New Electronics Self-Teaching Guide by Harry Kybett, Earl Boysen
Practical Electronics for Inventors by Paul Scherz and Simon Monk

Advanced:

The Art of Electronics by Paul Horowitz

>What Youtube channels are there?

https://www.youtube.com/user/EEVblog
https://www.youtube.com/channel/UChturLXwYxwTOf_5krs0qvA
https://www.youtube.com/channel/UCosnWgi3eorc1klEQ8pIgJQ
https://www.youtube.com/channel/UChtY6O8Ahw2cz05PS2GhUbg
https://www.youtube.com/channel/UC1rxMIOt82ieNE19w15U5YQ

>What websites feature electronics projects? Where can I get ideas for projects?

https://www.adafruit.com/
http://www.instructables.com/tag/type-id/category-technology/
http://makezine.com/category/electronics/

>Where do I get components and lab equipment from?

http://www.jameco.com/
https://www.sparkfun.com/
http://www.ramseyelectronics.com/
http://www.allelectronics.com/
http://futurlec.com/
http://www.ladyada.net/library/procure/hobbyist.html
And sometimes even just ebay.

>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

Friendly reminder to /ohm/, always tin your iron.

I got a little careless while soldering at 3:30am.

>>705930
looks good

like all good generals the op will evolve over time as anon finds new resources. think it should contain links to sites like digikey and mouser. and maybe someone should find a be all end all guide on things like soldering. maybe we can come up with a wiki like /emulation-general/ has over at /vg/ and that frees up the thread a lot with basic information always available and centralized.

>>705991
>where to get components
award goes to me for first person to ask about something clearly stated in the op

>>699618
what are the differences between all these SPICE programs. At school they keep pushing PSpice on us but it's not free...

>>706083
LTSpice: free
PSpice: not free

They are mostly compatible.

>>705636
u guyz

>>706114
You can try. you run the risk of it still being dangerous or looking weird. Is it out of the question to redo it?

>>705930

Another great supplier I definitely recommend: tayda electronics.

>>705930
pastebin of components/parts, pastebin of references and books and schematics, multimeter infographic: god tier - mid tier - cheap tier multimeters

So, I am Building a Gadget, that uses 9V at maybe 100mA maximum. Naturally I am thinking about making it battery compatible. It will also have a jack for a crappy, cheap 9V DC power supply (I mention the crappyness because of the voltage ripple). Now, my question:
Can I just put the jack and the battery in parallel?
I assume not, since the battery will draw a lot of power when discharged, from the supply and heat up because of internal resistance. Still does this work and if not, is it easy to make it work?

>>706218
Here's one for cheap tier multimeter:
The infamous DT-830 !
Millions of variants sold lol who originally made this thing?

>>706218

>Super Hard On

>>706220
>Can I just put the jack and the battery in parallel?
you could but then you (and everybody else who uses it) would need to remember never to plug it in with a battery in, because then the wall-wart would act as an unregulated charger for the battery

normally the external power jack disconnects one end of the batteries from the circuit, so that this cannot happen

easiest & safe: what you could also do is just build it with the external power jack, and then build a 9V battery pack that will plug into the external power jack. that way both couldn't ever be connected at the same time

>>706224

At least 4 of them died on my hands, didn't even get them to work for more than a year. Truly crappy, but 5 of them cost as much as a good multimeter, so it's not that bad, as long you don't use it for high voltages or currents.

I bought a branded one and I've been using it ever since.

>>706233
Which one do you have right now that is still working?

>>706230
those are some good ideas, thanks! Think ima go with the battery pack. But just out of curiosity, I'd need some kind of current regulation I assume?

How could I build a version of this that switches speeds on the fly?
https://www.youtube.com/watch?v=j_1mbC4n3Dk

Swapping out crystals is cumbersome and I wanted to make a DIY version instead of just buying the mod version that's for sale.

I have a general idea of what to do (maybe), find an oscillator chip that can go from 4~ to 25~ mhz, then wire it to a button sequence so that they send a charge which will change the frequency on the chip.
I have a shit ton of questions:
The battery for an SP is 3.7v so I need a chip that can run on that, then i need to have the chip wired to a ground on the motherboard right?
And what about actually changing the frequency in the chip, if I understand it VCOs will change frequency when introduced to current so I'd have to know the power of a buttons signal and then match that with a chip that will change frequency under that condition.

I was thinking a simpler method might be to have the female socket he has but rig the wiring between the original crystal and the socket so that if there's a crystal in the but the best I could think of for that is a physical switch that moves a metal contact that's wired to the original oscillators motherboard position from the original oscillator to the socket, and maybe have a speed changer with 3 oscillators.

Actually it probably makes more sense to have the speed changer internally but some of the chips are big and the GBASP is TIGHT with little room.

>>706442
forgot the picture of my terrible idea, forgive the mspaint.

>>706442

> so that if there's a crystal in the
*the original oscillator is no longer selected,

>>706218
what site is this?

Any neat tutorial on how to make a reliable high voltage power supply that doesn't explodes in your face or overheats after 10 seconds of use?

I have this flyback, I already labeled the resistance in the pins. What I don't know is what the two potentiometers at the side are for.

If it's 555 driven I could make a plasma speaker out of it and change the frequency more easily.

>>706473
One is almost certainly the focus voltage adjustment. Dunno about the other, but if it's actually an inductor, then it's likely to be some kind of picture shape adjustment.

>overheats after 10 seconds of use
Spark is almost a short circuit. Use bigger heatsinks, use lower supply voltage, add some kind of current limit.

>>706235

Just a promax. Spanish brand.

http://www.promax.es/ing/

New electronics enthusiast here.
In programming there's a thing called "code snippets" in which we can just copy paste into the "entire code" as long as we know it's functions and purpose.

My question is: Is there such a thing when it comes to making schematic diagrams? i.e "circuit snippets" that you just can just place/add. I would also like to know how you guys "segmentize/sectionize" your schematic.

tldr: how do you guys construct your code? I mean schematics? Do you also flowchart?

>>706496
Short answer: yes. Bit longer answer: it's a pretty central concept. For example, let's say you want to amplify something. One option would be to drop in pic related.

>>706498
All right. Now I see we have the "backbone".
just like in
<html>
<body class="amplify">
</body>
</html>

Can you pls show how that looks when you expand it one more level? like adding elements, etc. Thanks brofist

>>706499
its difficult to compare electronic systems to code. impossible in html.
when you write code you are transforming data, you have an input, processes and an output.
you consider what steps you need to do to the data and then break it down into steps.
electrical design is similar and you quickly pick up component combinations, what they do and how to use them.
until you get into it its hard to fathom i suppose.

>>706499
Ha-ha. But ok, let's say you want to go one level down in hierarchy and look inside a factory-made opamp. You'd find blocks like differential amps, current mirrors etc, all (usually) connected in a rather standard way. Or for a more practical example, you could replace the "opamp" block in that basic schematic with a circuit made by combining your own differential amp with an existing opamp.
If you want to go up in hierarchy, that opamp + resistors combination would be a gain block. You could simply replicate it to form a stereo amp. Or you could, less obviously, combine two of them with a (different than earlier) differential amplifier to get an instrumentation amplifier, which is in itself another useful block and available as an IC.

>>706514
+1 to this guy. well-put. thanks. I fucking love /diy/

>>704970
I did that and it worked, thank you
Now, because I am too lazy to go to the store, I implemented the rectifier with LEDs instead of regular diodes. It does work, but would there be a benefit if I used regular diodes instead?

HAH BACK FUCKERS

ask anything.

Is there some sort of a reference sheet for understanding all the shit written about transistors, making sense of it relatively simply?
I'm looking to get something that handles 2A at 12V with low capacitance and logic level gate but I get lost way too easily in all the various shorthands for stuff describing the transistor.

>>706473
A properly made flyback driver can work continuously for weeks without a problem - even in short circuit conditions.
Look for "zvs driver" if you need high current output.
If not, the 555 timer will work perfectly.
Note that flyback transformers work best at a precise frequency, you'll want to have a pot to fine-tune the 555.

Also, beware. That flyback can be prone to overvolting :
read http://boginjr.com/electronics/hv/flybacks-guide/

>>706473
>overheats after 10 seconds of use?

You need proper heat sinks and not overload the rating of the transistors.

>>706224
I bought one for about $8 several years ago. It never worked properly. All of the digits were fluctuating randomly.

>>706590

Thanks!

>>706590
>555 timer will work perfectly.
You can get the right frequency, but flybacks are more efficient with a sin wave than square wave. RC oscillators are better.

>>706636

I don't know how those work, for me it's quite easy to mess with 555. I don't care if its kinda inefficient, as long as I can achieve something like this http://boginjr.com/electronics/hv/flyback-driver-2/#monsterflyback I'll be happy.

The page >>706590 posted redirects me to a huge load of information, thanks again.

>>706636
Square or sine wave depends on how you use it.
The ZVS drivers use a sine wave but depend on the rewound (big gauge very small number of turns) primary.
It's basically not a flyback transformer anymore when you do that.
If you drive a flyback with the original primary and a sinewave you get a pretty lame transformer since the turn ratio isn't that high.

So guys. Have a 4000 joule 1800 volt capacitor bank and was wondering what you guys think would be the best resistor to bleed it would be.

>>706672

0 ohms

>>706679
Bleeding is where you let it discharge very slowly over several hours so repairmen don't get a shock, not where you discharge them as fast as possible.

>>706672

10kohm 1 watt should do the job

>>706667

Good to know.

>>706672

Should of worded this question better.

So first of all I am using this capacitor bank as a large pulse discharge capacitor but I want to make sure that if something goes wrong the bleeder resistor can bleed away the energy at its maximum value. What would be a good resistor to put on that won't mess with the operation of the bank but will also discharge it at a reasonable rate.

>>706689
>10kohm 1 watt
It's 1800 volts, so there will be 0.18 amps (324 watts) going through the resistor when the cap is fully charged. Remember this happens while the device is running, not just for a brief period when its turned off and you want the bleed. A mega ohm resistor would be a better choice.

>>698995
Forget about it, you'll never make it!
Save your money and do something else instead, alright?

What is the maximum frequency a transistor can work at? I've seen gain-bandwidth product but have no idea what it means.

>>706957
The transistor's spec sheet should say it. It's fT (transistion frequency). The rule of thumb is the the larger the transistor and the smaller it's maximum frequency.

>>706695
It depends on how much time you want it to discharge.
I'd recommend anywhere between 100kohm / 30W to 2Gohm /2W
They would respectively discharge in approximately 400 / 8000 seconds.
That's a long ass time if you have to be fiddling with it constantly but good enough if you just want someone to not die accidentally after putting the thing in a closet.

>>706957
It depends on what you're doing and how. If you're using it as a saturated switch, the switching time parameters are more useful than the transition frequency. To reach the stated speed you need to drive the base quite hard. If you don't, it'll be slower. In that case you can make guesses about the rise/fall time by assuming the current through Ccb will be just enough to kill your base drive.

>>705312
Looks kick-ass anon, not even an electronics hobbyist and that makes me jelly.

So does anyone have any idea where I would find a cap that's rated for 2000+ volts and 1000uF +

I need it for smoothing a current that is going from ac to dc

>>707405

Also as a side note my circuit will be running at 1800 volts and the ac was running at 60hz.

>>707405
>>707406

Do you have a step up transformer on the AC? There's no need for 2000 volt capacitors if you're just putting the AC through a bridge rectifier since that will only output around 100V DC peak to peak.

You can find capacitors like that in old CRT TVs.
You can also get the voltage and farads you need with multiple capacitors. Putting them in series adds up the voltage tolerance but decreases net capacitance according to 1/(1/c1+1/c2+1/c3...). Put sever series strings of capacitors in parallel to add up to the capacitance you want.

>>707410
Well first of all i really messed up my calculations. Capacitor needs to handle 2800 volts but only has to have a capacitance of 28.57uf.

Last time I use an online calculator instead of using hand calculations.

>>707423

That is a really big capacitor, relatively speaking. No consumer appliance will have anything even close to that size. You'd have to buy one online from somewhere.

As a side note, the fact that you mention "2800V" and then had to ask where to get one PLUS "online calculator" throws up a ton of red flags...

>>705312
gibe schematics!

Also are you French?

>>705930

To the sticky it goes.

>>705930

What software should I use to print circuits into A4 to do the toner etching method without complicated resizing and size adjustments?

I've been using gimp to make some simple designs, the grid helps to make neat traces, but when I print it I have some resize problems and I often have to print it twice.

I won't pay for proprietary programs since this is just occasional.

>>707943

No, eastern Spanish, why do you ask?

I don't have the schematics, I can say you the input is 19 volts DC, the variable resistor is 4.7kOhms and the second resistor has around 350-400.

Both outputs have diodes to prevent damage when operating with transformers or other inductive elements.

Noise is canceled with 100nF cap at the input and 1uF at the output.

Each output is connected to the lateral pins of a toggle switch, and the center pin is connected to the voltmeter. The other lead of the voltmeter goes to ground.

The 2 LEDs of the screen are standard white, 1kOhm resistor in series with the input was good enough to provide a good amperage.

The toggle switches go from the positive input to the input of the LM317.

I had this kinda /diy/ related fun night two days ago.
It's so fucking stupid I feel I have to tell it to somebody.
I was with my friend Nicolas. We were building this modified sine wave inverter to bring with us for a camping trip later this year.
So I breadboard the thing and hook up my cheap multimeter on the HV side of the transformer to see if it works.
I forgot to add a flyback diode to the transformer so the multimeter took a good 5 seconds of 5-6000 volts in its face.
I hear the arcing inside.
The lcd starts to blink erratically
> SHIT
I power the thing off but the multimeter seems to work.
So I'm just going through the functions too see if I fried anything.
What the fuck.
No, it's reading the most stupid shit.
It brings up "666" and "NO" from time to time.
Sometimes the segments light up like a Christmas tree and the thing shuts off after a few seconds.
We're both laughing our asses off.
The multimeter is now our fortune teller machine.
We have a drink downstairs.
Nicolas is drinking a bit more than usual because he failed his bachelor project and has to work 4 months more on it.
I'm fine but he got completely drunk
> Bro, I'm taking a smoke outside
It's dark outside now and he's been outside for half an hour.
He's smoking pot and lying on the wet asphalt next to the street.
I bring him inside. He's high as fuck.
He's also sad and stressed out because of all that bachelor thing.

At that moment, I have that most stupid idea I kinda regret.
Get inspired by comic
> Pic related
> Hey, Nicolas.
> w...whaaaat...
> The multimeter talked to me, It says you're going to hell
> F..FUCK you man. F...fuck you
> It's true ! Look at it for your self
> Bring the multimeter and power it up in front of him
> It reads .666 and beeping like it's dying
> n..noo... fuck you it's n..not true

He gets up and takes the multimeter for himself
>I..t's bullshit man

At this point I'm biting my tongue not to explode in laughter
> cont

>>708019

> cont

So i go upstairs to get something to film him, it's just to damn funny.
I can't find my camera.
When I get downstairs again, he's not there anymore
> FUCKFUCKFUCKFUCK NONONONONON
I didn't hear a door closing
Get outside, he's high but he can still walk pretty fast.
He's not outside.
Ask neighbor if he saw him, he didn't.
At this point I'm shitting my self.
He probably started flipping the fuck up because of my stupid joke.
I call his sister
Tell her what happened
She comes with 5 friends
We're all collectively flipping our shit
Searching inside the bushes, behind cars...etc
> Get called back inside
> They found him

He was in the basement asleep on the floor

They bough him home
Laughs were had

>>708024
>>708019
The multimeter in question
It's like it's possessed or something

>>708032

I hate when that happens...

>>705930
>>Where do I get components and lab equipment from?

>http://www.allelectronics.com/
No no no NO no NO.
They sell surplus shit and rarely provide any data sheets. I consider them to be about as reputable a company as Harbor Freight. If you want to know what you're actually buying you should consider the following suppliers.

http://www.mouser.com
http://www.alliedelec.com
http://www.newark.com

Admittedly mouser's website is pretty fucking cumbersome to navigate. Often times I resort to just using their PDF or hard copy catalog to find things. All three sites give you data sheets and manufacturer part# so you can pit them against each other to find the best prices between the three when you're building a part list.

>>707983
In school they teched me Circuit Wizard, i think there is a free version for it somewhere.
Also there's ExpressPCB, i think it's free but i don't like it because it has too little pads.
A lot of people reccomen EAGLE here, but i haven't tried it yet.
Remember that to do toner transfer you'll need a laser printer and special paper, not common office paper;vegetable kitchen paper (sulfurized or sth) is the best (i heard).

>>708045
Well, sometimes you can get deals and parts at allelectronics that you can't get anywhere else online.

Mouser is a rip-off store. $13.20 for ONE transistor socket? Jesus Christ!

>>708080
Mouser is not a place for buying one of anything.

>>708045
I hope that someone buying components will at least check all of the sites on the sticky and look for the best deals.

I'll add those sites to the sticky before the new thread comes up.

>>708080
Practically no-one has used transistor sockets for decades. That's part of the reason why they're expensive, if you aren't buying surplus.

>>707990
Thanks!

I find it hard to visualize what you're talking about, without seeing a schematic. However I am thinking of doing a variable power supply like that, based on the LM317.

How hard can it be eh? :P
Did you have issues with your power supply?

>>708042
>>708032
be kind to the machine spirits

>>708046
Eagle Lite is free, you have to pay for the pro version.

I picked up ExpressPCB very quickly but format is their own although people like Futurlec now accept it as well.

>>708150
Should have mentioned DesignsparkPCB - produces Gerbers, fully featured and free and if you play with project boards I find PEBBLE a handy simple layout system.

>>707983
You can use this if you want.
It's licenced to my school.
http://www.mediafire.com/download/wx2id5ud6hwg7d8/Setup_Sprint-Layout50.exe

Stupid novice question time, but can someone tell me what this component is, it had a black shroud over it with the number 103 on the top, pulled it apart due to curiosity, still cant work it out.

>>708214
It's an inductor.

>>708214
10mH inductor

>>708224
>>708225
Thanks!

So any advice for a guy who's going to start taking classes to become an electrician besides, get gud with math and don't fuck around on site?

>>708235
What kind of Electrician?
The doing wiring in a house type? High voltage power grid? Electronics?

>>708259
Dunno haven't started yet just prepping. Looking for anything you guys feel like sharing.

>>708271
Are you already equipped with the bare minimum ?
Pay a visit to your local dump. Look for electronics and try to debug/repair them.
When stuff is really broken beyond repair, unsolder components, make collection.

I do that on a weekly basis and learn from it a lot.
The sad thing is you'll notice a lot of the shit people throw in the garbage is almost always not broken or faulty in any way.

>>708277
Thanks will do

>>708111

It's extremely easy, you just need basic soldering abilities.

My power supply works great, not a single fault, I've been working with high voltage circuits and drawing a significant amount of current, bringing the LM317 to it's limits, yet no signs of overheating or failure. (Use good heat sinks of course)

When working with HV a spark got into the negative output, what fried my 555 timer drive, I also shorted it between the high voltage output and the positive output of the LM317 with me in between (quite painful). Despite this still works flawlessly, it's like the LM317s are indestructible.

The only inconvenient is you can't draw more than 1.5 amps per output, but I don't need more, in fact, the power supplies we have at my uni are rated 2 amps.

I'll try to upload a sketch of the schematic.

>>708111


It's extremely easy, you just need basic soldering abilities.

My power supply works great, not a single fault, I've been working with high voltage circuits and drawing a significant amount of current, bringing the LM317 to it's limits, yet no signs of overheating or failure. (Use good heat sinks of course)

When working with HV a spark got into the negative output, what fried my 555 timer drive, I also shorted it between the high voltage output and the positive output of the LM317 with me in between (quite painful). Despite this still works flawlessly, it's like the LM317s are indestructible.

The only inconvenient is you can't draw more than 1.5 amps per output, but I don't need more, in fact, the power supplies we have at my uni are rated 2 amps.

I'll try to upload a sketch of the schematic.

>>708284
thanks! you're so helpful and nice :3

Stupid question :
I'm trying to charge a lead acid battery with a lab powersupply.

So I set my powersupply to 14.4 volts and check with my multimeter. It all fits.

I connect it to the battery and the voltage across the battery reads circa 13.1v

Is this figure going to go up as the charge builds up, or am I supposed to compensate at the powersupply so that the voltage across the terminals is 14.4 v ?

>>708287

Mine is powered by a 19 volts, 2.5 Amps laptop charger, which it's embedded in the box with all the other components (as seen at >>705314 ), it has a heavy duty switch to power it, the switch uses both neutral and live wires to avoid current leeching by the charger.

Outside of the box I have a connector to plug in the grid voltage, it's pretty convenient since I can unplug it and carry the power supply easily.

I have not included those parts because you'll have to deal with grid voltages and it's not too safe for beginners. Although it's easy to figure out.

If you use a laptop charger or similar you can use the formula I provided to figure out R2, I recommend R1 to be 4K7, since some current must flow from the adjust pin to ground.

>>708307
Interesting and compact power supply, I am designing mine but I'm doing with a transformer+diode bridge+caps scheme and instead of only an adjustable output I am putting a +5V fixed output and a 12V symmetric output.
How do you deal with the laptop charger heat?

Well, we hit 300 posts. When would be a good time to start a new thread?

>>708290
What voltage is the battery designed to produce?

>>708350
About now?

Be sure to post links to the new thread in here.

If I had 10 capacitors rated at 10 volts each ( arbitary number ) wired in series to allow 100 volts overall then how would I prevent blowing a cap over the entire capacitor bank?

New thread

>>708779
>>708779
>>708779