/diy/ - Do It Yourself

>>28308

nope

solid state realy

>>28300
dude.

this is a terrible idea. why can't you use a relay?

>>28310

What's a terrible idea?

They do make transistors that switch 120v.

I just can't think of the model names

No transistor will do. Those are for DC. You need a triac and probably an optoisolator to isolate the ac from the signal.

>>28315

You need a diode bridge around it.
You might want to consider triac instead of transistor.

Or that solid state relay. What's wrong with them?

Small fet: BSS131

TIP31C

>>28335

I want to do fading/pulsing effect on strings of lights that run on 120v AC without having to do something more complex like varying the duty cycle.

>>28319
He didn't even state he was going for DC. XFMR? What the heck are you doing with this OP?

BC177

>>28364

trollface.jpg

>>28348
You'll need something that will sink a lot of heat then. How many watts of lights? My bet is you'll have to use a triac and duty cycle based throttling.

>>28371

I've built a box with an out let in it, so the number of lights will vary.

I already figured a heat sink would be needed.

Not really a problem I have so many old aluminum chunks from old computers that if I were to sell them for scrap metal I'd probably be a wealthy man.

>duty cycle

I knew you were going to say that.

well at any rate I'm going to try it with one of the high voltage models suggested above.

What's the worse than can happen?

>>28300
>AC
>single transistor

Well trolled sir.

>>28348

argh, you can control 120V AC, using very simple circuit, utilizing triac, diac and RC circuit, if you want to steer it using other analog signal you add one transistor :roll:

>>28450
also it would be good to isolated it from 5V, so add linear optoisolator

>>28450

I don't believe you

post schematic

>>28476

I'm not here to prove anything, anyway use google images *sight*
Try searching even this "phrase": triac diac rc

>>28499
so what your saying is you don't actually know what your talking about you're just speculating?

>>28513

Was this modern-day "trolling" or are you possibly serious?

>>28513
i don't speculate, i simple have enough experience to state some things.

>>28527
But some how your alleged experience doesn't translate into a schematic?

forgive me if i'm skeptical bro

>>28519

Whose's trolling?

he makes a claim without evidence then expects me to believe him?

A triac.

>>28539
>>28546
don't get me wrong, but; learn2electronics

You can make such easy schematic by your own, anyway google is fool of it.
You can modify it by placing transistor (with diode bridge), so you can (with steering signal) increase capacitor loading current, therefore lower loading time so the triac will start to conduct earlier -> lamp will shine brighter.
C'mon, you can come up with this logic yourself.

>>28570

relax man I'm just trying to get you to do my google leg work

calm down

>>28584
nah, i'm not angry or sth, just trying to give you fishing rod instead of fish.

>>28300
You wouldn't use a transistor for switching AC, you'd use a triac. If you didn't know this then you probably shouldn't attempt a project using 120VAC house current, you'll either start a fire or kill yourself.

>>28604
>wouldn't use a transistor for switching AC

stonedface.tiff

>>28604

>derp

You can switch 120 with a transistor.

>>28604
Fuck, you can, unless you exceed breakdown voltage
you'll will be switching only half of the signal - over or under the 0V

>>28640

The other half cycle either goes through the body diode (mosfet) or comes out from base (bjt). Not good.

OP I am working on a similar project (controlling a heating element (120V, 10A) with a 5V microcontroller output and I'm using a triac.

I based almost all of my circuit off this application note from Microchip:
http://ww1.microchip.com/downloads/en/AppNotes/00958A.pdf

Now I'm just waiting for my triac samples to arrive in the mail. . . .

>>28660
Yeap, but sometimes you can live with that, or it's desired.
However my point was only proving that it's possible, not finding applications;)

>>28620
>>28622
>>28640
ITT: One of two classes:
1. Idiots who know nothing about electronics, but are SURE they know what they're talking about
2. Trolls

And now, we get them to sort themselves into one of the two classes.

Refer to the picture. You are running 120VAC into the anode of this device. What voltage is at the cathode?

>>28620
>>28622
>>28640
You're idiots who don't understand electronics.
Neither a bipolar transistor nor a MOSFET conducts current in BOTH directions, only in ONE direction, just like a diode. It has NOTHING to do with the voltage rating of the transistor, is has EVERYTHING to do with the fact that it IS a transistor. At best you'd get half-wave rectified DC. At worst you'd get a smoking hole in your PCB where the transistor was. Your lack of understanding of this identifies you as someone who should NOT be experimenting with house current, you'll start a fire and/or kill yourself. You must use a triac or an electromechanical relay to switch AC house current.

>>28687
You, I can't tell if you're a troll or just a worse idiot than the other idiots in this thread. It is not something you can "live with" nor is it "desirable", it's bad design and shows a lack of understanding of the basics. GTFO.

>>28660
>>28657
..you two, on the other hand, understand what you're doing. Carry on.

Op do you mean a Transformer?
Transformers change voltage and amperage from one level to another level. if the voltage goes up the amperage goes down and vice versa.

Transistors are logic gates where you ably a current to a wire to stop current from going through another wire.

Transformers are easy to find or buy
second had stores, pawnshops, electronic parts store.

or you can make one yourself.
Iron Core either
double torus
single torus
U shape
Pole

Make sure to use single strand wire, with thin insulation. the thinner the insulation the better the magnetic field.
the thinner the wire the greater the chance of over heating, burning through the insulation and short-circuiting the coil.
120v to 5v
24:1 ratio
24 coils in the main coil for every coil in the secondary coil.
2400 and 240 would be good coils

phone charger

>>29919
>>29977
Pretty sure hes not converting the power, hes switching.