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Electronics => Beginners => Topic started by: random555 on April 02, 2021, 01:44:43 am

Title: clothes peg spring inductance
Post by: random555 on April 02, 2021, 01:44:43 am
pretty odd question I thought up, but if anyone has one of those old wood clothespegs laying around with the metal spring in them, does that little coil spring have any inductance? I figure as an aircore metal coil it should have something, but I only have a simple mm so I can't test it myself.

thanks
Title: Re: clothes peg spring inductance
Post by: ataradov on April 02, 2021, 01:49:03 am
It will, of course. Literally everything has some inductance. Intentional coil will have more than a straight wire.

There are formulas to calculate all of that.
Title: Re: clothes peg spring inductance
Post by: amyk on April 02, 2021, 02:30:41 am
https://en.wikipedia.org/wiki/Inductance#Calculating_inductance

You can also look for "air core inductor calculator" on the Internet.

As an order of magnitude estimate, it will be in the few uH range.
Title: Re: clothes peg spring inductance
Post by: MikeK on April 02, 2021, 02:43:57 am
Doesn't the air core inductor calculator assume copper wire?  The clothespin spring is some kind of crappy steel.
Title: Re: clothes peg spring inductance
Post by: ataradov on April 02, 2021, 02:56:20 am
They assume lossless conductor, so copper would be closer. But there is a lot of fudge constants there, so it does not matter all that much. Those formulas are only correct for low frequencies, limited dimensions, etc.
Title: Re: clothes peg spring inductance
Post by: xrunner on April 02, 2021, 02:58:46 am
pretty odd question I thought up, but if anyone has one of those old wood clothespegs laying around with the metal spring in them, does that little coil spring have any inductance? I figure as an aircore metal coil it should have something, but I only have a simple mm so I can't test it myself.

thanks

Sure it does. But I think the "coils" are touching (i.e. they aren't made of enamel insulated wire) so the inductance might not be as much as you might get otherwise.