Re(updated) Simple Flyback Driver


Introduction: Re(updated) Simple Flyback Driver

Do you want a simple $3 solution to make a 20-30 kv power supply for your electronics? Well here you go:

I modified the photos from so that it would work with a modern dc flyback transformer thats found in most modern tvs.

I am not responsible for any damages or harm that result from following these instructions.


Step 1: Prepair the Parts You Need

You will need:

  • Soldering iron (15/30 watt)
  • Duct tape
  • Thick(ish) wire
  • (20~24) Gauge magnet wire (or copper radioshack wire)
  • NPN 2N3055-type Transistor (radio shack part # 276-2041)
  • 27 ohm 1 watt resistor (5watt if use with 300amp battery)
  • 240 ohm 1 watt resistor (5watt if use with 300amp battery)
  • Heatsink for transistor (the bigger the longer the use)
  • Switch
  • Box to put it in
  • 12-24 volt power supply (i have tested it on a 12v 1amp wall transformer and it works fine and a 300a lawn and garden battery)

Q and A

Were can I find that type of flyback transformer?

Well, in a dumpster if you can find an old CCD TV or monitor (the types that aren't thin) crack one open (don't actually crack it open use a screw driver please :-) ) and pull it out

Were can I find 20-24 gauge mag wire?

I took mine out on an old amplified fm antenna but other sources are good and it doesn't have to be mag wire; it can be soled copper wire too.

Were can I find a switch?

In one the things you took apart to get the flyback or the mag wire if you still cant find one try radioshack

Were can I find the power supply?

In your basement car closet junk pile you name it (please put a volt meter on it to test voltages)
also you can use a 300 amp lawn and garden battery from lowes or were ever.

Were can I find you?

Email I will be more than happy to answer your questions

Step 2: Winding the Flyback

Grab your flyback and some of that mag wire and pliers and have a seat

Bend the tip of the wire a little bit and wrap the wire around the ferrite core (see the pics for help) 5 times for the feedback and 15-20 times for the primary and burn the tips with a torch or a lighter to burn off some of the insulation on the wire so your wires can get a good connection also dab some salder on the wire if the salder sticks you have a connection (see the pics)

if you want to use higher amps use thicker copper wire you only need 5 turn primary and 10 turn secondary

Step 3: Puting It All Togeather

Follow the schematic EXACTLY. I did find that polarity matters on the flyback' s feedback windings. if it still dont work revere the feedback winding connection

Step 4: Hv Lines

Finding the HV+ is easy; it's the thick red wire on top.

well strip your hv+ line, then power op your driver then touch each of the pins until you get the biggest arc (below is a pic of where mine was) DON'T GET SHOCKED! THIS COULD KILL YOU AND REMEMBER TO DISCHARGE YOUR FLYBACK AFTER EVERY USE BY CONNECTING THE HV+ WITH THE HV-

Now solder on a wire to the HV-.

Congratulations! You're done with the hardest step!

if you don't get any arc try reverseing your feedback lines or swapping your resistors with 3-5 watt during this my 1 watt resistors fried with my 300A supply

Step 5: The Case

I really don't care what case you use for the flyback. Just no metal cases, please. I used an old wooden box I had. Make sure that your case has holes near the heat sink.

Radio Shack part # 270-1809 works fine.

(Also if you add a POT to the input voltage you can adjust the output)

the output seen in the photo is 1.5" and running off a 12v 300A (lawn and garden battery)



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    Jacobs ladder anyone?
    I have been troubleshooting my 555 plasma speaker and found this so I'm gonna go rewire it for this then drive the circuit with the audio input thanks for the diagrams

    Funny, i used internal the wirings of the THT and used it as a coil hooked to a CDI circuit to run a 2 stoke chainsaw engine. Simple CDI circuit, added optical + trani trigger circuit + optical trigger switch + adjustable trigger sensitivity. For fun i hooked it to my 351W and it ran like a charm. Produces big blots too

    It gets hot, i used one from a printer (2 coils with <1 ohm), i mean the cables get hot. (One nearly melted within 2 secs)

    done with 25N120 IGBT & 200 E & 68E resistor.


    thanks for showing how it works

    but salder is spelt solder

    Hey, I really liked your project! This is a good quick'n'dirty solution for a high voltage power supply... Thanks. I'm just a bit confused in the part of the amps. You said that there was a '300 amp battery'. Isn't it supposed to be in milliamps? Because a 60 amp power supply is already a factory one and will certainly melt the wires. Anyway, good project.


    I liked this project. Will build it. Thanks Alex, and keep up the good work.

    I liked this project. Will build it. Thanks Alex, and keep up the good work.

    I liked this project. Will build it. Thanks Alex, and keep up the good work.

    what if i put a 12 volts ac supply?

    Here are my results with this circuit.

    Also I recommend using a fast diode in reverse bias across the transistor collector and emitter in order to protect it from back EMF spikes. The transistor will not last very long without it in my experience.
    1 reply

    thats really awsome

    Great tutorial. However, I would really appreciate if anyone could tell me why I couldn't get any sparks at all, something seems to not work despite me following exactly the instructions... MY flyback is as well of the same type as yours , my psu is 0-12v 2A but I get absolutely nothing.. ?

    1 reply

    Flybacks have an internal diode. switch your wires around. try again

    it worked i probily built 5 of these because it wouldn't work with my 9 volt battery and i thought something was wrong but thanks

    it worked i probily built 5 of these because it wouldn't work with my 9 volt battery and i thought something was wrong but thanks

    Yes. Pretty much any power transistor will work. It doesn't even have to be NPN. However, the 2n3055 will eventually fail due to the HV fed back through the primary windings. If  you can salvage the driver transistor from the television, it will work great because it is designed to withstand the HV.

    If you add a flyback diode to the transistor could you prolong its life? I'm assuming the damage is caused by reluctance of the inductive load. Do you know if this is the case?