Measuring the capacitance of an inductor or Inductors

[Possum]

....

OK, I'm not a retard, I'm trying to hide the truth which is I AM LEFT BRAIN CHALLENGED OK? Now my secret is out, go ahead laugh, point yer fingers, call me LB negative, logic dysfunctional, can't do math in his head, overly creative air head, I've heard it all, BUT I CAN DRAW, so put that in yer pipe and smoke it
:

[RedHouse]

...(waiting for jonson's punch line)...

There's no gay/phedophile connotation there, so he may be slow to reply.

[Possum]

....

OK, I am getting lost in the bottom part of the capitance formula. 40x5980 squared, I get 5.721664 with a little 10 hanging off the end. Can't I just round that off to 5.72? then divide 3.4 by that and I get .5944 this is Farads? .5944 farad Correct or not?

So using this method I have two pickups. The '63 is7.756K 7.2khz peak, 3.96Henries, 23.08Q

so I get 1.236 Farad for the '63

For my self made pickup it is 7.69K 7khz peak, 4.411Henry, 25.22Q

so for that one I get 1.173 Farad.

So is this right? Trying hard to understand this, at least I can see that the Patent is noticeably different, which it definitely is, probably due to the magnet wire .

[Mike Sulzer]

OK, I am getting lost in the bottom part of the capitance formula. 40x5980 squared, I get 5.721664 with a little 10 hanging off the end. Can't I just round that off to 5.72? then divide 3.4 by that and I get .5944 this is Farads? .5944 farad Correct or not?

No, way too big. I am not sure what you are doing. This is based on Joe's example, you said. Where is this example located?

[Joe Gwinn]

The pickup is absolutely fine, not a thing wrong with it or the LCR meter and DMM would give weird readings, which it doesn't. 6.2Khz seems odd to me for a 7.78K humbucker. The lead on it is only 3 inches long. AC resistance at 1khz is only 10.8, right in the pocket for a PAF. The DMM was connected to either side of the 1megohm resistor, is this correct?

Hard to say from the text description alone. Please publish a circuit diagram.

[Possum]

.....

Go back a page I posted a scan of the Joe Method for Health and Tonality. DMM is connected to either side of the 1 megohm resistor, everything else is the same.

[Possum]

.....

The example is on the scan.....

[Joe Gwinn]

OK, I am getting lost in the bottom part of the capacitance formula. 40x5980 squared, I get 5.721664 with a little 10 hanging off the end. Can't I just round that off to 5.72? then divide 3.4 by that and I get .5944 this is Farads? .5944 farad Correct or not?

So using this method I have two pickups. The '63 is7.756Kdc, 7.2khz peak, 3.96Henries, 23.08Q

so I get 1.236 Farad for the '63.

One Farad is a huge capacitance. A 1.0 Farad film capacitor would be the size of a commercial refrigerator. (Electrolytic capacitors are far smaller in volume for a given capacitance and max voltage.)

Typical pickup self-capacitances are around 100 pF (1.0*10^-10 Farad).

So that "little 10 hanging off the end" was the exponent (the power of ten), and is too important to be ignored.

The easy way to get from Farads to picofarads is to multiply the result in Farads by 10^12 (probably entered as "1e12" or the like). Example: (1.0*10^-10 F)(10^12)= 100 pF

If what the calculator showed was 5.721664*10^-10 Farads, that's 572.17 picofarads (pF), which is way too large for a pickup. So there is something wrong.

[Joe Gwinn]

The example is on the scan.....

Diagram looks OK. I guess the fastest way home is to publish your step by step calculations, with all intermediate numerical results. Then it should be easy to see the problem.

[Possum]

....

I think this is over my head
My calculator gets 5721664 with a small ten hanging off the end. I can use the EE key to enter those small digits, they're called "exponents?" I still don't understand what they mean. I'm going to bed....

[bbsailor]

I think this is over my head
My calculator gets 5721664 with a small ten hanging off the end. I can use the EE key to enter those small digits, they're called "exponents?" I still don't understand what they mean. I'm going to bed....

Possum,

Pronine Electronics Design - LC Resonance Calculator Try out this web link.

Just fill in the pickup inductance in Henries and the resonant frequency. It will tell you the equivalant pickup capacitance in pf. This will not strain your brain with scientific notation.

Joseph Rogowski

[Possum]

....

Thanks I'll try that. I did try one that claimed to be the same but it gave nonsense answers.

I think there is something wrong with my calculator. It has an EE entry pad. If I enter 4 and then 04 exponent and hit the equals key it gives me 4000. I know that is wrong. I read up on exponents and all it is, is how many times you multiply something by itself. I don't understand why (40 x 5980) squared is giving me 5721664 with exponent 10. That means I am supposed to multiply that number by itself again ten x ten times itself? Doesn't make sense.......

[Possum]

.....

OK, IS THIS RIGHT? I entered frequency and inductance only. This is the '63 PAF

[Possum]

.....

This is one of my buckers.
I noticed that how high I turn up the juice on my signal generator will also change the resonant frequency driving it higher at maximum output, maybe thats whats confusing Joe?

[Joe Gwinn]

This is one of my buckers.

Well, 117 pF is plausible.

I noticed that how high I turn up the juice on my signal generator will also change the resonant frequency driving it higher at maximum output, maybe that's whats confusing Joe?

Drive voltage should not matter.