Coil Construction

[tansis]

Couple of easy questions....well sort of

1> How do you calculate the inductance of a conical shaped coil ?
2> Litz wire , do its benefits justify the extra expense ?

Can anybody tell me of a uk/europe source for this wire?
sadly no prize for guessing what I am building, thought it would be nice to have some fun and do some "old school" electronics. Have been inspired to attempt a bit of scratch building....

 

[stevez]

I've known what Litz wire is for a long time but never knew why they make it that way. I know a little more now - litz-wire.com is a place to look. You might contact them for some ideas.

Quite a few amateur radio operators have backgrounds or experience with this kind of question and actually understand some of the "why" behind designs. One forum I check into now and then is amfone.net - you might also check QST or QEX magazine archives for some info.

 

[stevez]

Another site- lodestonepacific.com has lots of good info on litzwire including some data that helps demonstrate the differences in behavior. From what I gather so far, reduced losses and higher Q is a reason to use litz wire in some cases.

I've always wondered why they wind some coils the way they do - multi-section chokes are a good example. Conical shape has aroused my curiosity too. I am sure these inductors behave somewhat differently as frequencies or currents change just don't know how shape plays into it.

 

[chemelec]

There is a JavaScript Calculator I designed for Conical Coils on my Website. I use conical coils quite a bit. They have a good structial strength and exibit lower inter-wire capacitance than most coil forms.

**broken link removed**

Take care........Gary

 

[laroche73]

conical coils

1> good question, sounds like a homework problem for a MIT student :? . Consulted my physics book to review the basics, conical inductors (or capacitors) weren't covered, no surprise.

Gary, nice website, I'll have to check out the rest. "just happen to have a calculator for conical inductors lying around here somewhere..."

benefits - 1) reduced capacitance at the expense of larger size 2) better structural strength for vertical forms, anything else?

What are some applications of conical inductors where the standard cylindrical kind wouldn't perform acceptably well?

 

[tansis]

I came across the the use of a conical coils and Litz wire by accident, was searching the web for info on building a crystal set, I know the circuit and the formulas but wanted to see what others had done and was immensely pleased to find many wonderful sites where this humble circuit has become an object of an almost zen like attention to detail.