PCBWAY PCB service

PCBWAY PCB service


Plasma arc lighter

Flyback transformer

Build the Flyback transformer

Another option, if we don’t have the LCD screen, is to build our own high voltage transformer. I’ve use this small transformer that I’ve took out from an old computer power supply.

flyback converter circuit

Un-wrap the transformer and carefully take out the ferrite block. Be very gentile, this thin ferrite can crack very easy and this is the most important thing that we need from this transformer. Now unwind the transformer 0.2mm copper wire and store it for later. Now we have to make our own coils. First we will wind the secondary coil. For that we will need a lot of very thin coil copper wire. You can find this kind of wire in any quartz old Chinese clocks.

Copper wire out from clocks

flyback transformer windings

We will make the secondary coil with 0.1mm copper wire. We have to make about 1000 windings for the secondary coil. But be careful. Since inside of this coil there will be a high voltage and the layers are very close one to each other there could be plasma arcs inside of the transformer and we don’t want that. In order to prevent that to happen we should put 10 layers of scotch tape every 200 layers or so to give a little bit of space between the differential voltages. Take something with round shame and a diameter bigger than the inside part of the ferrite core. Measure the core dimension and start wrapping some tape to give the limits of the coil. I’ve used this screwdriver. Now wrap some tape with the sticky side on the exterior like so. Now we can start winding the secondary coil. Take the 0.1 mm wire and tape it on one side of the tool. Start winding. Make sure that every 200 or 300 layers you put a few scotch tape layers. After that keep winding. I’ve finished my coil Now I’ll put some white glue on it to be sure that the coil won’t move. I’ll let it dry. Our secondary coil is ready. Put another layer of tape to separate the secondary coil from the first one.

flyback transformer coil

Now, for the first and flyback coils we will use 0.2 and 0.4 mm copper wire. Wrap together the two wires at one end. First wind the primary coil in one direction. It will only have 5 windings. Now wind the flyback coil in the opposite direction. It should have about 10 to 12 windings. Now what we should do is solder some thicker wires to the secondary coil output. I will solder this two green wires. Place the output in such a way that one wire will be on one side and the other in the other side of the coil. Now secure the wires and give a final two or three layers of tape. The coil is ready. Take it out carefully and join the core with the coil in the middle. Now, using some tape once again secure the ferrite core in place very tight. Use super glue if necessary. I will give another layer of tape to make sure that is very tight and isolated. Our flyback transformer is ready.

flyback transformer how to build

Now we have to mount this next circuit. We will use one 50 to 100 ohm resistor and one diode. The transistor could be a N50 high voltage NPN transistor or a IRFz44 mosfet. If you use the MOSFET, just remove the diode from the circuit. That’s it.

Next page: