How measure inductor 10nH -100uH without LCR meter?

[berger.h]

I need measute incuctor promali low inductance indictor 10-1000 nH
I have not LCR meter.
My first choice is Resonance measurement, but maybe you advise a better method

 

[SLK001]

The "grid dip" (AKA, Resonance measurement) method is the old school method of measuring inductance.

 

[BradtheRad]

I guess you chose LC resonance because it is not as much affected by ohmic resistance?
On the other hand an inductor-only measurement has a problem, because the L/R time constant is thrown off by internal ohmic resistance.

I try various oscillator arrangements with inductors, just to see different ways they behave. I like the idea of making do with the least number of components. It seems to me that the simplest circuit should be easiest to get a direct measurement from. And perhaps the most correct measurement.

 

[berger.h]

I need to measure large in size inductors with low ohmic resistance, wire about AWG 21 - 24.
Therefore, ohmic resistance can be neglected, perhaps

But I have second question.
I have torid RFC in drain power amplifer transistor on about 15MHz 50V


I measured L=12.5uH but toroid core is unknown

-**broken link removed**
-ferrite 4C65
- Iron Powder Material 7
- any other?

- - - Updated - - -

I think, which material is most suitable for this type of coils

 

[Kripton2035]

build some simple meter like this one : **broken link removed**

or buy one of these multi-testers around $15 : **broken link removed**

 

[carpenter]

GM328A is a nice toy, but not for measuring nH inductor, this gadget measure low inductace coil only with resonsnce capacitor in series. Therefore, in this case an adult signal generator better a more accurate choice.

 

[BradtheRad]

It is fine to apply a frequency sweep while looking for the resonant frequency. Alternately this thread discusses an LCC oscillator driven by a half-bridge. Resonant frequency is detected automatically.

https://www.edaboard.com/threads/362790/

 

[KlausST]

Hi,

Connect L and C in series, then at resonance frequency you get very low impedance.
Check if your generator can handle this.
The benefit of this configuration is that the C blocks DC..

In other configuration you need to take care that DC current may cause neasurement errors.

Btw: in headline you talk about 10nH .... 100uH, which is 100 000nH,
But in text you talk about 10nH ... 1000nH only

Klaus

 

[Kripton2035]

GM328A is a nice toy, but not for measuring nH inductor, this gadget measure low inductace coil only with resonsnce capacitor in series. Therefore, in this case an adult signal generator better a more accurate choice.

oups, did not notice the 100nH ... thanks for pointing it out.