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Flyback Transformer assistance requested

I am having problems with the flyback transformer. For primer on where I am at, following the tutorial to locate the 0v pin the voltage was win the specified range. The flyback is from a old monitor that was monochrome but was still working.  No datasheet could be obtained. 10 pins if it matters.

I am following the struct on using the single transistor driver.  Specifically a 2n3055 from radio shack. Lets pretend i wouldn't waste your time if i didn't triple quadruple check the wiring first. using 24v dc power supply schematic and page i based my driver on.  

i am not getting the high pitched noise from the flyback. i have 5w 220 resistor and a 5w 27 resistor . my resistance ratio is important. correct? since there is a voltage divider there. i know its vague but can someone give me some direction to work out my problems


safetec5 years ago
Lets see if I may be of any help here. The single transistor driver is a good starting point as it is so easy to make. I have tried many power transistors like the IRPF250, IRF630 and the 2n3055 and they all seem to work fine. However i fried 8 250's, 4 630 and 4 2n3055 before realising that the number of windings must be 3 and 5 or otherwise you blow the transistor when you apply more than 12V 1.5 A. I used 2x220ohm 5W resistors and a IRF 630, the 630 works great on lower current, much better than the 250 and the 2n3055, but it has its limits. If the wires are getting hot then chances are that you are drawing too much current and thats usaully a sign that the transistor is gone.
grenadier5 years ago
Well first of all the 2n3055 driver is crap, complete crap. Use something better such as a mosfet half bridge or a zvs driver.

Second, finding the 0V pin is hard to do because the transformer has a very high resistance. Just arc to the pins when you get it working and you'll find the pin.