Inductors in parallel, technically

[Behemot]

I know that in theory, it works just like resistors so it's fine. So, in practical life, is there any problem why inductors in parallel should not work?

I'd like to do a heavy filtering curcuit, basically with all the things which are usually in transient filter in PSUs, just make it external as I have my doubts about some PSUs filtering efficiency even if there are all components which should be in there. The reason is I'd like the PSUs I am measuring to not get interfering with high-frequency noise from the network, and also them not to send noise back to my equipment (O-scope and so).

I have whole bunch of input filter coils harvested from PSUs and I'd like to re-use them, but I'd also like it capable of say 2 kW of power flowing through, so that's why I think it would be better to use some in parallel. I'll measure their actual inductance and pick up only the same ones for this task of course.

[selldoor]

Re: Inductors in parallel, technically

http://diyaudioprojects.com/Technica...calculator.htm


EDIT Hmmm whilst the calculator seems to work i dont think their formula is correct - before I email them - am I right?

[Behemot]

Re: Inductors in parallel, technically

I know that. I am asking if it works in reality. You can theoretically combine diodes and transistors as you want, too, but in reality, they differ a bit piece from piece. You will quite often be surprised what happenes if you combine them and relly on their theoretical overall power capability.

[redwire]

Re: Inductors in parallel, technically

One hassle with paralleling inductors, is that you get unwanted mutual coupling. The flux from one inductor couples with it's neighbor's flux and you get less inductance than expected, due to transformer action. If they are shielded cores, or mounted at right angles to each other on the PCB, it's not a big deal.
Also I'm not sure how much current-hogging you'd get, due to unequal resistance and inductances- I think that if even one inductor saturated it would ruin the group's performance.

[Behemot]

Re: Inductors in parallel, technically

I plan doing several complete filter-groups in a row so hopefully they'll be able to somehow split the filtering and prevent saturating.

I'll try the 90° trick, good point

[Radio Fox]

Re: Inductors in parallel, technically

http://diyaudioprojects.com/Technica...calculator.htm


EDIT Hmmm whilst the calculator seems to work i dont think their formula is correct - before I email them - am I right?

There's nothing wrong with their formula.