Resistor sizing

Hi Ryan, I found the same info. I will keep looking for a bit and see what I can find.

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If I was troubleshooting this I’d reverse engineer the system and draw a schematic for the circuit. That would help me figure out the circuit’s intended function.

Then by comparing the created schematic to published circuits that perform the function I should be able to work out the likely types and values of any mystery components.

It is almost never cost effective to do this, but sometimes cost isn’t a big factor.


Yeah, in this situation it will not be cost effective to reverse engineer it.

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What do we think if I have the room of using two non-inductives in parallel?

Being source-connected to a beefy FET and the apparent non-inductive winding suggest a current-sense application, and a low resistance value.

As Paul suggests, a repair effort would call for some reverse engineering. Not simply to infer an appropriate value of what appears to be a component with non-standard markings, but also to understand the likely extent of any collateral damage or causal factors.

As for fabricobbling a replacement out of parallel resistances, that could be a bit sketchy due to the potential to increase the loop area enclosed by the resistor and the current return path, and thus the parasitic inductance of the segment. Or it could work out OK. It’s tough to gauge without a good understanding of the circuit.


Hi Rick, good point. I think this one will be a non repair situation.

Thanks everyone for your input.

One day I hope to have enough knowledge to contribute back as well!

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