How do I determine the "vampire current draw"?

Other Hardware General Electronics
1

This topic came up in a conversation the other day with my son.

How do I determine the "vampire current draw"?

I understand there's current draw from the 110v ac to 5v dc converter, then you have current draw from powering the microcontroller sitting there idle waiting for something to happen.

This would still be in the Mah range correct?

2

  • That's mA not Mah.
    Depending on the hardware, it could be as low as microamps.

  • If the circuit is already made, you can measure the vampire current (if any) with a DMM.

  • The OP needs to let us know what the design guidelines are exactly.

3

I've moved your question to its own topic; please do not hijack topics.

4

An Uno R3 draws about 50mA@5volt. Consuming 5 * 0.05 = 0.25 Watt.
That 50mA current draw is almost independent of the work that the processor does.
Leo..

5

:+1: