Unknown Inductance

[iONic]

Anyone know the aprox. inductance of:

80 turns of .5mm wire around a toroidal core with an outside diameter of 40mm?

 

[Russlk]

It depends mostly on the material of the core; do you know what it is? If you have a signal generator and scope, you can figure it out by resonating the coil with a known capacitor. I have a 1/4% cap that I use for that purpose.

 

[Sceadwian]

1/4% cap? Where do I get one of those? =)

 

[Russlk]

It is used in the 540 series of Tektronix scopes for the time base. I don't know what they are using now, but it is probably just as accurate. BTW, it is not +-1/4 % but just +1/4%.

 

[ronsimpson]

Don’t get lost over the “0.25% capacitor”. Use a 5% cap.
If you use a signal generator and scope they are probably not as good as the 5% cap.

 

[mister_e]

Usually a resistor in serie with your inductor, a signal generator and a scope will be enough to do the whole thing.

http://www.sxlist.com/techref/inductor/measure.htm
**broken link removed**
http://michaelgellis.tripod.com/68hc11/ind.html

 

[ArtemisGoldfish]

Hmm, could I measure inductance with my old tube oscilloscope? (Just alittle math required in reading the dials ) Note that unfortunately, my scope lacks a grid pattern on the display. Instead of an oscillator, could I hook the resistor/inductor pair to the scope's 6V 60 Cycle test lead?

 

[mister_e]

You can also do it with a variable resistor (pot) and a transformer. The trick is to play with the resistor untill you have 1/2 of Vin on the inductor leads.

Look at the inductance formula.

The following method should do the trick.
https://www.tpub.com/content/neets/14193/css/14193_36.htm