I was just doing some searching on google for how to make an 8 Ohm/100W Dummy Load using some 5W Ceramic resistors, and found this useful webpage, so I thought I would post a link to it here just in case other forum might be interested, anyway, here it is:
As it turns out, by my calculations if I put a total of ten 82 Ohm/5W Ceramic Power Resistors in parallel with each other, that will give me an 8.2 Ohm/50W Dummy Load resistor, so, maybe if I double the value of all the resistors, and put twenty of them in parallel, that'll get me closer to what I want.
So, 2 X 82 gives us a total of 164.
Now, here's my thinking, if we put ten 164 Ohm/5W ceramic power resistors in parallel with each other, we effectively get a 16 Ohm/50W Dummy Load, and, if we put two 16Ohm/50W Dummy Loads in parallel with each other, we effectively get.......an 8 Ohm/100W Dummy Load.
The question is, are 164 Ohm/5W Ceramic Power Resistors available? most likely not, I'll consult my Jaycar Electronics Catalogue to find out.
Turns Jaycar don't stock a 164 Ohm/5W Ceramic Power Resistor, the closest next value up that they do stock is a 180 Ohm/5W Ceramic Power Resistor, Cat. No. RR3280.
So, how close can we get to 8 Ohms with a resistor value of 180? let's see.....
If we put ten 180 Ohm/5W resistors in parallel with each other we get an 18 Ohm/50W Dummy Load.
If we put two 18 Ohm/50 W Dummy Loads in Parallel we get.....a 9 Ohm/100W Dummy Load.
This is one Ohm larger than we need, but, we didn't take into account the resistor tolerance, or how much +/- of the marked value the resistor/s actually measured, and we also didn't take into account the very small resistance of the solder leads either.
Last edited by DrNomis_44; 05-05-2023 at 05:21 PM.
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