Thanks very much.
Inductance of 820 ohm 10w wirewound
Jun 21, 2011
25 Replies
**No. You are simply measuring the inductive reactance. All you require is a signal source, a high freqency millivoltmeter, a known non-inductive resistor (or resistors) and a pocket calculator.
You are over-thinking the whole thing. As Phil has already stated, trying to measure inductance, with a resistor of such a value is fraught with difficulty.
Trevor Wilson
www.rageaudio.com.au
** Weeeeellllll - that is what I am asking you to try !!!
** That is the whole point.
The nature of the "coil" is much the same over a wide range of resistance values.
As is the turn to turn capacitance.
** No it isn't.** You have not tried to do it and are still making silly assumptions.
Read my other posts in this thread.
.... Phil
"Trevor Wilson"
** That second job is not possible.The Z value will be exactly the same as the resistance.
Try 100MHz instead and then see how a few pF of strays ruins the outcome.
.... Phil
Yes, understood. Certainly this ancient brain now gets it that R swamps the L and the C. Unfortunately (because I had much to learn from him) Phil's nasty childish ways and foul language have now caused me to block him, so I won't see any of his wisdom.
I took a hammer to a 820 Ohm 7 Watt wire wound resistor
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This damaged the wire in the process, but it allowed me to measure the diameter to be about 0.04mm.
The end caps are like shorted turns which will reduce the inductance, which is probably of the order of 1 microHenry, and completely swamped by the resistance.
HTH, G.
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