DC transformer OR a really small relay

Thread Starter


Joined Feb 16, 2009
Any help would be REALLY appreciated. I have a science fair sort of project, and I am generating between .5 and 1.5 volts, but ONLY .01 milliamps. I have been looking for a tiny relay that would accept that voltage and control a circuit with a 1.5V battery powering a 1.5V flashlight battery. I cannot find such a monster, then I wondered if I could create a tiny transformer to power a relay that is reasonably available. Many are 5.0V but the amperage is the real hurdle I think. If anyone can help finding a tiny relay to work as I hoped, or have a solution to hand winding a relay to make something work, I would be most appreciative. Thanks for your help.

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Joined Dec 19, 2007
A bipolar junction transistor needs only 0.7 volts and very little current to turn it on. It can be used as a switch to turn on your 1.5v circuit. How much current does your 1.5v battery circuit require?



Joined Feb 4, 2008
A transformer does not works with DC.

You need to use a BJT transistor to amplify the signal as to be able to drive a relay.