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I want to create an Inductance meter with an arduino nano, for that I follow that link whose theory convinced me : tutorial

(The Diode on schematic remove analog negative voltage, Edit: I have wrong, excuse me surely for prevent inductor negative voltage because out signal not contain diode or maybe in the comparator ?) and then the comparator convert it into square wave based on ON/OFF DC ? Getting wavelenght or pulse in time and then calculating resonant frequency and finally the inductor value based on known capacitors values.

This tutorial use an LM339N comparator, but I learn an I read : op-amp can be used as comparator.

I have not a comparator but I have an TLV2462 op-amp ,can I use this TLV2462 - Op Amp - Dual Rail-to-Rail as comparator in place of LM329N comparator ?

My goal is to create an Inductance meter for 'nH' unit... I learn, I read but i'm confuse. Also, I know the discharge inductor can create a big negative voltage spike. I would not want to burn my arduino (perhaps the diode is here for that), that's why I'm always on the theoretical part.

Thank's for your help.

enter image description here

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  • \$\begingroup\$ Try to extract the schematic from the video, and edit it into your question. I'm not going to wade through some fuzzy video looking for it. \$\endgroup\$
    – JRE
    Commented Jun 13, 2018 at 19:41
  • \$\begingroup\$ Note that an ATmega already includes a comparator, which is typically utilized when making capacitance measurements. Have you evaluated if it is suitable? \$\endgroup\$
    – Chris Stratton
    Commented Jun 13, 2018 at 19:46
  • \$\begingroup\$ @ChrisStratton, thank's, I did not know and I saw that nowhere. But how should I go about it for inductance \$\endgroup\$
    – f14284
    Commented Jun 13, 2018 at 19:48

1 Answer 1

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There are many ways to perform this measurement but when it comes down to nH accuracy every mm of trace length counts as adds 0.5~1 nH/mm.

The Op Amp must support the current and bandwidth required to drive the low impedance of nH ranges.

Another possible method is to use a linear LC oscillator , limiter and 8 bit binary binary counter to lower the frequency measurement.

http://www.falstad.com/circuit-java/e-eclosc.html

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    \$\begingroup\$ Enable site java in browser for the simulation to work. Change anything you want. \$\endgroup\$
    – D.A.S.
    Commented Jun 13, 2018 at 20:04
  • \$\begingroup\$ For the moment i want to try it with op-amp, i read on op-amp TLV2462: 6 MHz gain bandwidth & 1.6 V/us slew so you can drive fairly fast signals, this is good for nH ? thank's \$\endgroup\$
    – f14284
    Commented Jun 13, 2018 at 23:17
  • \$\begingroup\$ define good nH. resolution ? accuracy? please \$\endgroup\$
    – D.A.S.
    Commented Jun 13, 2018 at 23:35
  • \$\begingroup\$ accuracy and/on nano henries unit. thank's again \$\endgroup\$
    – f14284
    Commented Jun 13, 2018 at 23:56
  • \$\begingroup\$ Have you ever made a 1nH measurement before? What impedance of 1nH at 6MHz? ( skill test) and what current is needed for resonant cap at 5MHz and 1nH using 1.6V/us=dV/dt \$\endgroup\$
    – D.A.S.
    Commented Jun 14, 2018 at 0:51

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