Checking for Inductor Current Rating

[Wond3rboy]

Hi, How do i test whether and inductor can carry 50ma(as told by Bill).Will this work:

I take a 5V supply take a resistance of 4.7k(dont have a 5K one if it exists).Connect them in series and see if it gets toast?

 

[duffy]

Almost - that's only a milliamp, use Ohm's law. Also remember you have to add in the inductor resistance to get the total resistance. If the inductor gets too hot to touch it's probably a bad idea.

 

[Hero999]

You need 100R to get 50mA at 5V.

 

[Wond3rboy]

Sorry i miscalculated,i was wondering that there was something wrong(dont expect to make mediocre mistakes like that).Thanks just wanted to confirm this way.

 

[stefanodel]

Hi, How do i test whether and inductor can carry 50ma(as told by Bill).Will this work:

I take a 5V supply take a resistance of 4.7k(dont have a 5K one if it exists).Connect them in series and see if it gets toast?

Not always you cannot test an inductor in this way.
In this way you have only the idea that the wire of your inductor can carry the desired current but, you don't know if the core is satured. If the core saturates the value of your inductance will be very low.
If your inductor is an "air core" then you can do this test because air doesn't saturate.

Stefano

 

[Wond3rboy]

Well i have one of those ceramic type inductors.I already soldered them to my Junebug and hope they work.Thanks for your info.

 

[MrAl]

Hi,

Another rating an inductor has is the saturation current level.
This is the amount of current that basically turns the inductor
into an air core coil
Checking for this spec can be a little tricky because you have to
look at the current waveshape while the inductor is banged with
a squareish wave with some net dc offset (non symmetrical squareish
wave).

Another way is to use the inductor in an oscillator circuit that depends
on the value of its inductance for the frequency set level, while also
applying some dc current through the inductor. As the frequency
changes as the dc current level rises you can calculate the change
in inductance and get some idea how well the inductor will work
in something like a dc to dc converter circuit.