While the Flyback transformers can be salvaged from old/damaged TVs, they prove to be rare components, and finding a quality Flyback secondary is often a great challenge.
On the other hand, a good Flyback secondary can get easily destroyed , it the voltage level inside gets too high (the insulation is punctured internally).
This is why I’ve decided to build one with proper insulation from scratch, since the whole thing is merely a multi-layer coil. Using 0.2mm CuEm wire and a PVC pipe for supporting the coil, I’ve created a 2500 turns flyback. The winding was deployed on multiple layer, insulated with PVC tape.
This video shows a test run with this flyback secondary. Bottom line, I encourage you to try making your own Flybacks, since it’s quite easy. More on the ZVS driver here.
Radu Motisan
Hi Radu,
I have a question for you. I am helping a friend who builds mosquito zappers. He has been having a problem with the transfomers burning out either by the secondary shorting internally or sometimes the secondary shorts to the core. The transformers are 110 vac pri. and 4kv sec. He is using a 1000 pf 20kv cap across the secondary which is burning out sometimes. . The secondary is connected to 2 wire cages and have a space between them so when a mosquito enters the field it is zapped. Why would these caps and transformers be failing. I think whoever is making the is over rating the caps.
Thanks,
Jim
How do you take care of secondary endings?