Hi
I am trying to power a fan that draws about 4volts and 0.1A. I have a low voltage DC source of 0.5volts which isn't powerful enough even if I use a DC/DC converter. So using this I hope to charge some batteries which could then power my fan. What is the best way to do this?

Any suggestions are much appreciated,
thanks

 

Use the converter to increase voltage to a level high enough to charge your battery. You will need some means of limiting current to avoid loading down your supply. Then all you'll need to do is wait a very long time while the battery charges.

 

As always-more questions, what current can the 1/2 V source supply? Maybe its a solar panel or thermocouple and candle? I have trouble with a 4 V converter.

 

Thanks for replies guys, The source supply is a thermo electric generator. Across a 180 ohm resistor the TEG is outputting about 0.8 volts, so a power of around 4mW. So that implies a current of 4.4mA if my maths is correct!!

 

You might need to charge a battery for months at a power of only 4mW.

When the voltage is stepped up to 4V then the current will be stepped down to only 1mA or less.