Flyback transformer's driver's mosfet wires heating up

Thread Starter

resad indipa

Joined Jun 22, 2017
11
Hello everyone,
I'm trying to create a high voltage power supply with a flyback transformer, IRFZ44N and a 220 Ohm resistor. (200 ohm in the diagram should be 220 Ohm ) Here's my schematic. My problem is that the wires connected to drain and source of the mosfet becomes burning hot and melt the insulator around the copper wire. My power supply is a 24V 4A DC power supply. I used this setup for a long time before changing the the number of windings in the primary coils, then it stopped working. I have changed the mosfet and the resistor after that incident. Please help me to identify the problem with my transformer. Thank You!

Artboard – 3.png
 

DickCappels

Joined Aug 21, 2008
7,565
You can reduce the power dissipation by driving the MOSFET with rectangular pulses. That might be enough to solve your melting insulation problem. The pulse generator can be as simple as an NE555 oscillator.
 

Thread Starter

resad indipa

Joined Jun 22, 2017
11
You can reduce the power dissipation by driving the MOSFET with rectangular pulses. That might be enough to solve your melting insulation problem. The pulse generator can be as simple as an NE555 oscillator.
Sir, do you think there's a problem with my flyback transformer as this setup worked perferctly for a long time before I changed the number of windings of the primary coil?
 

DickCappels

Joined Aug 21, 2008
7,565
Now that you mention it, your problem probably is because of the number of turns. Maybe you can put it back with the turns that were working for a long time and then modify the turns a little at a time.
 
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