inductor current

[bublee]

hi all...... can u tel me how to test an inductor for a particular current....
i mean to say i hav an inductor and current 100mA thru it.. so how can i decide whether the inductor is going to take the current without damage??????????

 

[MikeMl]

It is not a matter of damaging the inductor; it is usually about the current that causes the magnetic flux path in the inductor to saturate, causing non-linearity and unpredictable circuit behavior.

For example, read this **broken link removed**.

 

[mneary]

If you only want to avoid damage, measure the DC resistance and use the formula for power. You'll have to use some judgment as to how much power the unit could safely dispose of, but you can get in the ball park.

Example: If an inductor is about the same size as a 1W resistor, and if it measures 2 ohms. I would guess that it could pass ( I = sqrt(P/R) ) where P is 1, R is 2, and therefore I would guess that the risk of damage is low if I keep the current well below sqrt(1/2) or 0.7 amperes.

If the wires are visible, measure their diameter and look it up in a table.

Of course as MikeML said, even if it doesn't burn up it may not work.

 

[Mr RB]

Power it up with a DC current and measure the temperature rise above ambient (allow 20 mins or so for the temp to stabilise). At full rated current they are usually less than 30'C above ambient. That will get you in the ball park. Then I would de-rate it maybe 30% to allow for current ripple.