Inductance Meter using 8051.

[kishore680]

I want to design an inductor meter. How to go ahead. I thought to use tuning circuit, where c will be predetermined capacitor and L is unknown(of course). Then, the output of tuned LC circuit will be a sine wave, which I will pass it to comparator (op amp as a comparator)as one input. The other input will be grounded. The output of comparator will be fed to the Microcontroller (8051) which reads the input pulses and calculates L using f=1/2*pi*squareroot(LC) . Is it right?. Are there any more suitable techniques than this?. Kindly help me out.

 

[andre_luis]

I would not recommend employ such approach, for many reasons.

You should necessarily work with a big set of capacitors, in order to reach entire range of Inductors values intended to measure. A manual or auto switch would be required for select into a set of (precision) capacitors. Another point concerns to the intrinsic non-linearity related to calculation, becoming fine tune somewhat not so simple.

I presume the best way to do that could be applying fixed voltage pulses directly on the inductor and measuring the current ramp, which is proportional to its value. This way you would deal solely with time domain, adjusting microprocessor timer prescaler to take proper range.



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