Created by
Created March 10, 2012
Last modified March 10, 2012
Tags joule   joule-thief   led   power   thief  


A high-power Joule Thief type circuit to drive a 1watt LED from a 1.5 volt source. A suitable driver transistor, like the 2SD965, 2SC2500, 2SC2655 MUST be used!
The second winding has been replaced by a PNP 2N3906 and C1.


Not provided.


Good circuit! Works well like it is. Thank you, very much! I made some changes that made the LED brighter and only draws 55 mA. First my NPN is a 2SC945. I changed the 75k resistor to a 39k and the 82 ohm to a 392 ohm. All other parts are the same except the diode. The only one I had was a 1N5819. It seems to work fine.Thanks again. Great Job! This JT has been running on a single AA battery for a week now.

by iKris
January 25, 2013

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