RE: Wire-wound resistors as dummy test load

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Original poster: "Mccauley, Daniel H by way of Terry Fritz <twftesla-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>


Rick,

No, that is not correct.  Resistors in series will divide up the voltage
across them according to the ratios of the values to the total resistance of
the string.  Current will be identical through the entire series string.
Power will divide the same way.

For example, a 100 ohm, 100 watt resistor would be equivalent to ten 10 ohm,
10 watt resistors in series.

Similar for parallel.  Powers combine as well.
For example a 100 ohm, 100 watt resistor would be equivalent to two 200 ohm,
50 watt resistors in parallel.

Dan


Matt,
Resistors in series will only have the wattage of the lowest rated resistor.
In your case wiring them in series will give you 800 ohms at 200 watts.

Rick W.


>
> I found 4 200-Ohm, 200-Watt wire wound resistors all the same brand, that
I
> thought I would string together as an 800 Ohm, 800 Watt, test load for my
TC
> power supply, while checking things such as PFC cap size, etc.  However,
when I
> checked them with my meters, I got these readings: