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Confused about flyback transformer circuit

Posted: Tue Nov 06, 2007 7:13 pm
by bugsingelyn
First, I don't post often but I do look at the forums whenever I'm bored. I don't know why I don't post more often, maybe I'll start now.

I've read a lot (I think) about flyback transformers, and I am a little confused about a few things. I am trying to make the simplist circuit that I found, which consists of 2 resistors, a flyback transformer, and a transistor. I have everything except the transistor, and the website from the wiki says that some work and others don't, and that it doesn't always depend on the rating. It has a list of transistors, and the only one that Radio Shack has is the 2N3055 NPN 60V 15A. It says that only 1000 volts or so is all it will put out, and I guess my question is does anyone have any experience with this transistor with a "new" style flyback transformer? If it really doesn't work, what transistor do you suggest and where can I get it? I also have a garbage-picked 36" TV, that I got the flyback from, so would it have any transistors I could use?

The website that I got the information from is:
http://www.angelfire.com/80s/sixmhz/flyback.html

Posted: Tue Nov 06, 2007 7:27 pm
by sandman
i tried to use that tutorial and failed :cry:

but i tried to use a transistor out of the TV i got the flyback so that could be my problem but i dont know

Posted: Tue Nov 06, 2007 8:00 pm
by Spedy
That circuit you are thinking of using REALLY stinks. On the transistor, 1000v is just the rating of the transistor. The flyback will make much more when run properly. Try something like the circuits here: http://uzzors2k.googlepages.com/flybacktransformer

There's real power in those circuits, just look at the pictures.

Posted: Tue Nov 06, 2007 8:54 pm
by TurboSuper
I didn't have any luck with the circuit on the wiki either. My transformer just made alot of weird assed sci-fi sound effects, which were pretty cool, but alas, no plasma arc.

The circuits Spedy linked are probably much better, since they work off a fixed oscillator.

Posted: Tue Nov 06, 2007 9:24 pm
by sandman
lol, mine didnt even make sounds :x

i looked at the the diagrams on the linked page and the first one doesnt really make sense to me but oh well

Posted: Wed Nov 07, 2007 1:49 pm
by jimmy101
Sandman, the circuit isn't that bad.

The Ne555 is a very common timer chip. You hook up a power supply, a couple resistors and a capacitor or two and it generates a square wave output (an oscilator). Depending on the values of the reistors and capacitor you can change the frequence of the oscilator. RadioShack has a similar chip that actually contains two 555's on the same chip, part #LM556, $2.

You might try Mouser or Digikey to see if they have the MOSFET. Both of these suppliers will also have many flavors of the 555 (Ne555, Ne556, Sa555 ...)

Posted: Wed Nov 07, 2007 3:20 pm
by sandman
the thing that doesnt make sense to me it the line that comes out of pin 7 and then connects to the other line, but what is the arrow coming off of it pointing the 50k resistor?


Edit: Jimmy thats the first time i noticed that you didnt boldsomeones name :wink:

Posted: Wed Nov 07, 2007 4:03 pm
by dewey-1
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Posted: Wed Nov 07, 2007 4:21 pm
by bugsingelyn
Ok, I like the 555 timer circuit thingy. But it never says anything about the flyback being new or old, so I assume that it doesn't matter. I will go to The Shack tonight or tomorrow and post how it works. I just saw that it still needs a pretty powerful transistor though, will anything that is fairly hefty work for that, like the 2N3055?

sandman - I don't know much about schematics but I think it is a variable resistor, like a potentiometer.[/quote]

Posted: Sat Nov 17, 2007 2:45 pm
by MetalMSTR
yeah i will make one of these i can find a flybak for 50 cents or a dollar (5pesos mexicanos or 10 pesos) near san juan comercial center :lol:
and the thing like 555 and diodes etc are really cheaper here (5 a10 peos each one) but transistor ... they variates a lot in prices
the circuit is really simly

Posted: Sat Nov 17, 2007 9:38 pm
by Los Frijoles
Kind of off topic, but could this be used to drive a tesla coil? My dad built a tesla coil during college and used a digital 'something' to resonate the coil. Most people in his used a sparkgap, so he got a D on the project even though it was more stable then the others.