Measuring inductance-LCR meter,Bridge or DMM adaptor?

[djsb]

Hi,
Does anyone have any ideas for a simple but accurate way of measuring coil inductance? Is there a circuit I can build that can work with a multimeter?
Thanks.

David.

[rossmoffett]

There are DIY circuits around if you search, I just bought a $20USD LCR meter from eBay a couple of years ago.

There are several circuits you could build that you could measure with your meter, they're basically LCR meters with no display.

[Zad]

It depends on how many you have to do, how precise you want it, and the approximate value.

If you have an oscilloscope, make a parallel resonant circuit with a known capacitor, pulse a low voltage across it and measure the frequency of the sine wave it produces. f=1/(2*pi* sqrt (L*C) ) and rearrange to get the value of L.

[joelby]

There are plenty of standalone LC meter kits around - you could probably build you own from spare bits. Here's one available in kit form, but the page also has information on the calculations involved: http://www.rfcandy.biz/communication/imp_lc.html

[Rowland]

Take a look at the ALMOST ALL DIGITAL ELECTRONICS (AADE) website. The L/C IIb meter
http://www.aade.com/   I have had my meter for the last 10 years and it is invaluable.
Neil has a lot of data about the kit on the site.
The kit is full, in that it comes with an enclosure and can easily be built in an evening
Regards
Rowland

[jimmc]

If you're building from scratch, you can simplify the circuit (and loose the LM311) by switching to the PIC16F628 see
http://ironbark.bendigo.latrobe.edu.au/~rice/lc/index2.html

Jim

[joelby]

I can also recommend the AADE meter. The only thing is that it is quite expensive! But well worth it, really - especially with the optional SMD clip.