Wireless Power Transmission to light a 3 watt led bulb

Thread Starter

Aakarshya Umendra Verma

Joined Apr 15, 2017
Hello all. I am new here. I got a project to light up a 3 watt led bulb using wireless power transmission. I am using the following circuit with 22 copper wire. It is working but then the bulb goes off. I am using 2N2222A Npn transistor. I am not sure if I should include a resistor of what value on the base side. If you find any other flaw please do help..Primary coil ahs 14 turns and secondary has 7 turns. Thanks :)


Joined Aug 21, 2008
Yes, you should put a resistor in series with the base otherwise you will waste a lot of power heating up the resistor.

I hope you are not planning to use one of those little 9V transistor radio batteries because most of them can't supply the approx 500 ma or more that your circuit will need.
Similarly, a single 2N2222 will not handle the peak collector current you will need to reach 3 watts average.

Start small and experiment at low power levels then when you see what works you can invest in more expensive parts.

By the way, if you make both coils resonant at the same frequency you should see a improvement in performance. Another way to improve performance would be to go to a "push-Pull" output stage.

In your "receiver" circuit you will need to add a rectifier or two to prevent reverse voltage from being applied across the LED. Some LEDs allow 3 or 4 volts, some have internal Zener diodes that would short your receiving coil on every half cycle, and the manufacturers of some LEDs say there should not be any reverse voltage, so best to rectify the voltage.

It might be worth your time to look around on the internet some more before building anything.