alan smith wrote:
> Typically if you have two power sources, you diode OR them, so they will 
> not backfeed to each other.  Application is battery backed systems, etc.
>
> If you have one supply, say the battery sitting on a trickle charger, and 
> aother wall supply, both feeding a power plane,and if one supply is at a 
> slightly higher potential,

So you basically have THREE power supplies, all feeding the same circuit? 
Trickle charger, battery, and the wall supply?

And the "ground" levels of the trickle charger and the wall supply, are 
slightly different? So like, the trickle charger's Gnd is at 0V, and the 
wall supply's Gnd is at +0.5V?


> ..will it draw more current from the lower potential supply in order to 
> normalize the voltage on the plane?

Either I don't understand the question, or the question is wrong. The power 
supplies will be fighting each other, so they will both be supplying more 
current than is required by the circuit.

Vitaliy 

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