Let's Make Robots!

joule thief

Regulated Joule thief, how?

Many of you have seen or read about a Joule thief, and for the rest of you: http://en.wikipedia.org/wiki/Joule_thief. They come in a great varieties, google easily finds them. One thing that I like about the Joule thief is that it is so forgiving about the applied transformer, the circuit simply adapts to that ever you throw after it. No need for calculations or anything.

Joule Thief

There is not much to document in this project. I built a Joule Thief....who didn't ;-)

Mine is powered by a LR44 button cell (1.5V) and it light up a white LED which usually needs a minimum of 3.3 voltes to light up.

I just built it to test how long the LED can light with this one battery (it might be interesting for throwies). 

Will update the blog when the battery is completely depleted.

Power on time: January 14, 2012, 3:30PM

step-up or joule thief or.. ?

I`m trying to convert the wireless doorbell outside from battery to a renewable source such as solar or wind. My problem lies in that the battery required is a 9v.

My first thought was to produce a high enough voltage to charge the 9v but that might require more solar panels than I have. The 2nd idea was to use a lower voltage battery or super-cap as replacement and stepping up the voltage to 9v. I haven`t taken any measurements of current usage but I don`t imagine it could be more than a couple hundred mA while pushing the button and much lower in idle.