Cannot get joule thief to work
Your meter won't show anything. The output is actually voltage spikes of 4 to 40 kHz that in this setup may reach 25-70V. To see this, do as follows: In the above circuit, place a small 30-100uF/250V capacitor across the Collector-Emitter with diode in series with the capacitor. (Diode placed in upper capacitor arm direct toward capacitor.)

This capacitor will quickly collect the maximum voltage of your Joule Thief and show you a correct reading when you attach a meter to the capacitor. You will be surprised at the voltage.

Below I am presenting a fragment of your circuit, with the capacitor and diode setup to measure the voltage. Please ignore values of elements as they popped up by themselves - actually any capacitor and diode will do...

If you get nothing:


try switching ends of coils around.
try using variable resistor instead of 1k fixed resistor (0-1k) and try different settings. Use voltage source 1-2V


Best of luck.







simulate this circuit &ndash; Schematic created using CircuitLab