# Need help figuring out how much power to use.

I am trying to power 2 small fans that each have an input of 12v DC 0.12A (120mA). Do I need a 24v DC 0.24A (240mA) to power them both to max capacity?

I am trying to power 2 small fans that each have an input of 12v DC 0.12A (120mA). Do I need a 24v DC 0.24A (240mA) to power them both to max capacity?

active| newest | oldest~~combination~~summation of loads.A load will draw current from a voltage source by this equation

I_{load}= V_{source}/R_{load}Hmm. there is one caveat...failure mode.

It might be of some value at this point to explain how to protect your circuit (fans in this case) from faults, using either

a fusefor each load, rated slightly above the expected load current, orcircuit breakersfor the same purpose.for a load such as the ones you've indicated, I'd suggest a 200mA fuse, ie 2/10 A), so two 2/10ths Amp fuses, one for each fan.

Steve