Ferrite Core Inductors for Crossovers

[Keithj]

It seems not to have been mentioned so the techie bits.

It's the current through the windings that affects the saturation of the core. The flux density increases with current and eventually the ferrite core saturates.

Some ferrite is specified for audio use, however you'll need to check whether or not it's suitable for the current that you'll be putting through the windings. What you're looking for are ferrites that have high values for H and B in the specifications. I can't tell you what values would be regarded as "high", perhaps someone else can.

regards, Keith

[r_s_dhar]

If I were to settle down to winding air core coils, would the quality of the wire used make any difference? Specifically, can I use the enamelled wire generally used in winding transformers? Dont tell me that there are gold or silver plated ones!! I have used these transformer enamelled wires and have settled down to like the audio quality -- how could I be dissatisfied in the absence of any comparison?

please advise.

[Lisandro_P]

I've built quite a few inductors, and every time i used enamelled wire i saved up from different (dead) transformers. Works great for me!

[r_s_dhar]

Great help. Thanks everyone.

[kelticwizard]

Just thought that I would throw in that they sell enamelled wire specifically for winding transformers and inductors. In Designing, Building and Testing Loudspeakers, author David Weems recommends old transformers as a source of wire. It is not some sort of thing you are "getting away with"-that is what the wire is for.

Remember, the thinner the wire, the cheaper, but also the greater DC resistance. Try to keep the DC resistance under 1 ohm, if possible.

Otherwise, enjoy "rolling your own"!

[planet10]

Originally posted by kelticwizard
David Weems recommends old transformers as a source of wire. It is not some sort of thing you are "getting away with"-that is what the wire is for.

Another good source of enamelled wire is from the deflection coils off dead CRTs. Much easier to get at than old transformers, more plentiful, and i have even run across a few that use Litz-like wire.

dave