*Litz wire*

[Anonymous]

JC,
Litz wire was not named after some German fellow called Litz. Litz is short for "Litzendraht"
Litzendraht translated from German simply means "Woven Wire".
The main use of litz wire is at radio frequencies where the skin effect is all important. Many thin wires woven together gives you more surface area than a single wire does, Dave. * * *

 

[Anonymous]

I didn't say it was named after him, I said he had the patent. Does he? Or is it still open? <IMG SRC="/forums/images/smile.gif" BORDER=0 ALT="">
With the flyback, and short time after that, we are getting close to AM band radio frequencies here. 1 and 2 usec times and such. But alot of the time for most designs magnet wire is probably just as good. Or maybe thick skinned hookup wire, to keep capacitance down.
Just don't get hung up on needing high Q coils, or whatever.
JC

 

[Anonymous]

Hi JC, the two Daves and all,
Continuing the discussion down below, cross sectional eddy currents are important even in a single TX/RX coil. I have used stranded hookup wire to make coils for the SD's that are just as good as ones made with Litz wire. Even though the strands are in electrical contact with one another, the eddy current path is sufficiently attenuated so that there is no effect. Use an equivalent gauge of solid wire and it will not work, unless you go to a later delay when the cross sectional eddy currents have died away.
The other important factor is the self capacitance of the coil. Maybe with Litz wire this is less than that of stranded wire. Keeping the self capacitance low eases the damping arrangement and helps to achieve a fast switch off.
Eric.

 

[Anonymous]

Hi Eric,
Whoops, looks like the litz genie got out of the bottle again. The only thing I know for sure is between two large monocoils, one with 17 strand 30 awg litz, and one with 20 awg stranded pvc hook up wire. The litz coil damps faster and picks up external noise better (I take this to mean it is receiving better). Not so scientific, and certainly not definitive, out in the field probably not even important. Certaninly not the reason stated in the Candy patent. I have the litz wire around so I use it even for small coils. Never measured the self reasonance on the coils so don't know capacitance. This may be the only real difference.
Thank again.
JC

 

[Anonymous]

The trouble is that there are so many varieties of litz wire. There are two numbers given to any one type of litz wire. The first is the number of strands and the second is the AWG of the wire. So a litz wire maked 17-44 is made up of 17 strands of 44AWG.
Candy's patent calls for the use of smaller AWG's.
He provides a range of AWG's best suited for a detector. The number of strands the litz wire has will effect the amount of current you can put through your coil.
This is one very interesting point. You can easily make a coil with a fairly high resistance using litz wire. Sure it gets a little warm but I have yet to melt the wire!!! Dave. * * *