MY Power Supply Has Me Confused - can't control Current

[seanc]

Originally Posted by smithb98

The question again is, do they share the wattage between the two?

Yes they do.

Lets consider the resistors alone, w/out plating tank, for a full 10 amp draw:

The case of 2 x .5 ohm in series: effectively the same as a 1 ohm, 100 watt resistor. It will take 10 volts to get 10 amps. Both resistors will pass the full 10 amps, but each resistor drops only half the voltage (5 volts each in this case). 5 x 10 = 50 watts each. They're operating at their limits.

The case of 2 x 1 ohm in parallel: effectively the same as a .5 ohm, 100 watt resistor. This only takes 5 volts to get 10 amps. Both resistors will drop the full voltage, but current splits between them, so each passes only 5 amps. 5 x 5 = 25 watts each. Well under their limits.

Hook up the plating tank, that adds up to a few tenths of an ohm (how much depends on part size, temperature & anode-cathode spacing).

If you only have 10 volts available, the series configuration will limit your max current to 8.5-9 amps or so. You'd need more voltage overhead to get the full 10 amps.

The parallel configuration leaves plenty of voltage overhead. I'd use this one if it's enough to keep your PS from kicking out.

Sean

[smithb98]

awesome. thank you so much.