Inductance Measuring Adapter

[kinarfi]

Has anyone built on of these? I tried building a Simulation and it didn't work. It calls for a 74HC132, I plan to use a CD4093BCN which has a different pin configuration because I have it. Does any one have an understanding of how it works?
Thanks,
Kinarfi
Where I got the design, https://freecircuitdiagram.com/2009/05/12/inductance-meter-circuit/

 

[ericgibbs]

hi,
It works ok in LTspice.

 

[kinarfi]

Thank you Eric, could you please attach your .asc file for me to analyze, I basically copied yours, but I don't get your results, I too, use LTSpice . I guess I'll go ahead and build it and see if it works for real.
Thanks Again
Kinarfi

 

[ericgibbs]

Thank you Eric, could you please attach your .asc file for me to analyze, I basically copied yours, but I don't get your results, I too, use LTSpice . I guess I'll go ahead and build it and see if it works for real.
Thanks Again
Kinarfi

hi,
This is the part of the circuit that does the work.
All it is a square wave pulse generator driving into an inductor.

 

[BobW]

Op-Amp is 74HC132

Hmm, that's the first time I've seen anyone refer to a quad nand gate as an Op-Amp.

 

[SABorn]

I thought it was interesting how he got a 500mV reading on the multimeter when set to 200mV......What the??

 

[ericgibbs]

I thought it was interesting how he got a 500mV reading on the multimeter when set to 200mV......What the??

hi,
I dont read the authors text in that way..??

This circuit is designed to provide two measurement ranges. The low range will measure inductors with inductance value between 3uH to 500uH, and the high range will measure inductance values between 100uH and 5mH.

To calibrate this inductance meter adapter, connect a digital voltmeter, switch the voltmeter to 200 mV range, short the test probe and adjust the zero (R1) to give a zero millivolts reading on your digital voltmeter.

To calibrate the low range of this inductance meter adapter, switch the voltmeter to low range position, and select 2 V range for the digital voltmeter.
Test a known inductor that has a value around 400uH; adjust the low calibration pot to give correct reading of 1mV/uH. If you use a 400uH inductor then you must adjust the calibration to give exactly a 400mV reading.

For high range calibration, switch the range selector to high position and use a known inductor around 5 mH, adjust the high calibration pot to give 100mV per mH. A 5 mH inductor should give a 500mV reading on your DVM.

 

[SABorn]

I thought it was interesting how he got a 500mV reading on the multimeter when set to 200mV......What the??

Seen i was given a bad wrap for this comment perhaps we should look a little closer at the circuit and text.
As pointed out the text says........

For high range calibration, switch the range selector to high position and use a known inductor around 5 mH, adjust the high calibration pot to give 100mV per mH. A 5 mH inductor should give a 500mV reading on your DVM.

And the circuit shows the "range selector " as a switch in the circuit and not on the multimeter.

So yes it is a matter of how you read the authors text.

 

[kinarfi]

Has anyone built on of these? I tried building a Simulation and it didn't work. It calls for a 74HC132, I plan to use a CD4093BCN which has a different pin configuration because I have it. Does any one have an understanding of how it works?
Thanks,
Kinarfi
Where I got the design, Inductance Meter Circuit | Circuit Diagram

Attached is the original design with a red circle around the area I modified and made an OOPs, Since both scales have a 22k in them I figured I could just use one, and a single pole, trouble is, I didn't isolate the unused part of the scale, and got "back feed".
I can still get by with one 22k, but I still needed the 2pdt switch, attached is my current build, which does not seem to work.
Need to get my DSO 2150 usb scope involved, if it will work.
I have several scavenged inductors, but not sure of their ratings, one from a hard drive circuit board has "100M H002" on it, one has "CHK-176 JSI 9437", one has TLH-289A SYE9436, one has "TLN-2026 JSI" and one has "TLH-247 JSI247. If anyone know the value or where to find the value of these, please advise.
Thank You
Kinarfi