Troubleshooting the resistance of an inductor

Thread Starter

gkmaia

Joined Dec 22, 2018
34
Hi, I got a 223k inductor which is reading 53 ohms of resistance across itself. When I try testing continuity my multimeter bip goes crazy.
Is that normal?
Or should I never read more than 2 or 3 ohms in any inductor, no matter how high it's value is?!
 

ericgibbs

Joined Jan 29, 2010
19,017
hi,
Its possible for an inductor to have a highish resistance value, depends on the inductance, current rating and wire gauge.
What is the wire gauge on your inductor,?
E
 

DickCappels

Joined Aug 21, 2008
10,232
Some inductors are intentionally made to have high resistance. These are found in all sorts of low current power supply filter applications. They save money two ways: They can get by with a small bobbing and tiny amount of copper and a series resistor is not needed to damp ringing and increase impedance. See? Its not a problem, its a feature!

I have an envelope full of brand new small 39 mH inductors that have DC reistance of 260 ohms. Nothing wrong with them, its just that they aren't very high Q.
 

LesJones

Joined Jan 8, 2017
4,215
A mulimeter with autoranging on the ohms range can get confused when measuring the resistnce of an inductor. The meter changes ranges by changing the test current through the device under test. (Inductor) When the current through an inductor is changed it creates a voltage pulse. This pulse can cause the meter to keep changing between ranges giving a changing display. If you can turn autoranging off then you should get a stable reading.

Les.
 
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