PCB coil joule thief

Experimental PCB single layer transformer - proof of concept

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This year is Year of PCB coils ;-)
2x 29turns 6/6mil

I know that it is not effective, stupid, expensive, unpractical
but it is great education tool :)

Some boards from first batch are for sale on TINDIE PCB coil joule thief

Mini version on way square-inch-pcb-coil-joule-thief

sch - 409.15 kB - 07/13/2018 at 21:58


brd - 99.88 kB - 07/13/2018 at 21:58


  • 1 × BC546B Discrete Semiconductors / Transistors, MOSFETs, FETs, IGBTs
  • 1 × LED - White Fiber Optics / Emitters
  • 1 × Magic PCB with coil transfomer
  • 1 × Side switch
  • 1 × Battery holder

View all 6 components

View all 6 project logs

  • 1

    Order magic PCB with coil, Eagle boards files are included.
    All other components you can found in your drawer :)

  • 2

    Solder components, Transistor, Resistor, LED, Switch and battery holder, no more components required.

    No wires for transformer coils:), there is all on PCB :)

  • 3

    Insert battery to holder, minimum battery voltage is 0.5V

View all 4 instructions

Enjoy this project?



BillSF9c wrote 08/10/2018 at 18:45 point

Yes, but for edu purposes, think, a 1.5cm ring, die led flashing 1x/sec, small button battery... or, it flashes faster uf your hand is near emf. LED should be green, of course. 😉

  Are you sure? yes | no

Odie wrote 08/01/2018 at 05:35 point

Hi. The new design looks much better than the old one. I'm in a hurry to make a clone . So, do you have a plan to upload the new layout file? 

  Are you sure? yes | no

Sulivvan wrote 07/20/2018 at 15:26 point

Can you post the calculations for the coil, about a year ago i was making joule thiefs and i couldn't get the right calculations for the coil so i just made it by trial and error

  Are you sure? yes | no

K.C. Lee wrote 07/20/2018 at 15:45 point

Eagle CAD has a calculator inside for flat coil. Tools/Calculate Print Inductance

 I hit the menu by accident yesterday.  Also

  Are you sure? yes | no

Sulivvan wrote 07/22/2018 at 10:12 point

Lol i didnt notice , i will try it thank you!

  Are you sure? yes | no

bobricius wrote 07/20/2018 at 19:56 point

no calculation, I just draw biggest possible coil on 5x5cm board :)

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Sulivvan wrote 07/22/2018 at 10:13 point

Dam i wonder if it works on a smaller size

  Are you sure? yes | no

bobricius wrote 07/23/2018 at 09:01 point

I think yes, maybe I try sometime, but everything bigger is better :)

  Are you sure? yes | no

bobricius wrote 09/07/2018 at 21:00 point smaller version also working ... and little better

  Are you sure? yes | no

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