Art and Technology are Friends

“Joule Thief” LED Night Light

“Joule Thief” circuit is an inductor based voltage booster circuit to light LEDs with low supply voltage. The circuit was published in 1999 and has been quite popular. You can see the principle of the circuit here:

My version is a variation that uses single coil inductor, to make the inductor easily obtainable. I design the circuit using readily available parts only, to make it an ideal DIY project.

Please see the full article on Instructables (

Purchase here.

2 Responses

  1. Jeremy

    How will I need to modify the kit to leave off the light sensor and be able to power four LEDs?

    December 11, 2012 at 3:36 am

    • You can just leave the sensor off and the Joule Thief will always be on. You should be able to connect another set of two LEDs in pararel to the two LEDs in the circuit. However the brightness will be less.


      December 11, 2012 at 3:01 pm

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