Iron core choke measurement

[vintagekiki]

14
Respected Sir
You don't need to convince me about what you know.
I believe you that you know, and that is enough.

Let me remind, you did not answer me.

#12
Please explain me which PU and guitar speaker reproduces the frequency range from 30kHz to 50kHz?
What the human ear hears (registers)?

[Sticktosharingschems]

13

Boy I'm afraid you wrong portal.

Did you seriously just call me "boy"? Guess I should've expected casual racism from the likes of you.

[Steve Blackdog]

Did you seriously just call me "boy"? Guess I should've expected casual racism from the likes of you.

PEACE everyone!

I read that as “boy” as in “oh boy” or “boy oh boy”. Not sure it can be interpreted as racism, can it?

Do you have an answer to my original question? If so, let’s forget the altercation with Vintage Kiki and get back to my post. Peace ✌️

[Sticktosharingschems]

Iron core chokes aren't really an "off the shelf" item like resistors/caps, there's the aftermarket for common ones, but otherwise options are so limited that manufacturers are forced to have them custom wound. So most will just use an internal part number rather than list all the specs - internal documents would reveal the specs if required.

Easiest way to measure is to use an LCR meter, but you wouldn't be asking the question if you had access to one.

Soundcard and software have already been suggested, but there are other tools too. Do you have a scope and signal generator? A bench/lab power supply?

[Steve Blackdog]

Iron core chokes aren't really an "off the shelf" item like resistors/caps, there's the aftermarket for common ones, but otherwise options are so limited that manufacturers are forced to have them custom wound. So most will just use an internal part number rather than list all the specs - internal documents would reveal the specs if required.

Easiest way to measure is to use an LCR meter, but you wouldn't be asking the question if you had access to one.

Soundcard and software have already been suggested, but there are other tools too. Do you have a scope and signal generator? A bench/lab power supply?

I have a basic scope and signal generator. I have a few known output power transformers, but no variac type supply.

[vintagekiki]

#18

Inductance can be measured directly with an LCR meter, and indirectly with a tone generator and AC voltmeter.

https://www.instructables.com/Measuring-Inductance-With-a-Multimeter-and-a-Resis/

https://www.quora.com/How-can-we-measure-inductance-of-a-choke-coil-in-series-with-an-external-resistance
How can we measure inductance of a choke coil in series with an external resistance

https://www.wikihow.com/Measure-Inductance
How to Measure Inductance

https://www.antiqueradios.com/forums/viewtopic.php?t=134371
How to measure a coil uh or henerys

https://audiokarma.org/forums/index.php?threads/any-way-to-measure-a-chokes-inductance.244768/
Any way to measure a choke's inductance?

https://www.vintage-radio.net/forum/showthread.php?t=134815
Finding spec of unknown choke

https://www.youtube.com/watch?v=hd_qPx1xep0
Filter choke inductance measurement method

[Helmholtz]

The inductance of a ferrous core inductor is not a fixed value. Rather it varies with AC and DC current as well as frequency at least to some degree.

So using an LCR meter or the simple impedance method may not give realistic results.

E.g. measuring the primary inductance of an OT with an LCR meter typically gives values a factor of 5 (or more) lower than in real amp operation.

A power supply filter choke sees DC and AC currents and both influence inductance.

So it's essential to adjust inductance measurement conditions to those in the application.
The paper by trobbins I linked somewhere above shows how to correctly measure a choke with DC bias (on the first three pages).
No software and high frequencies required.

[vintagekiki]

About choke inductance measurement

Page 38
Inductance, Reactance Chart

1)
http://thoughtmountain.com/inductor_calculator.html
Inductor Calculator

http://dicks-website.eu/coilcalculator/
Coil and transformer calculator

https://www.vintage-radio.net/forum/showthread.php?t=126445
DC choke inductance measurement

https://www.youtube.com/watch?v=hd_qPx1xep0
Filter choke inductance measurement method

https://www.youtube.com/watch?v=RFyC1-aPI3w
Calculating, winding and measuring a choke