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using Litz Wire to build 18" Coil
if we use Litz wire to build 18" mono coil for Minipulse what would be the results any body explain ?
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Don't try it unless you are well versed in coil construction and the technology involved. If not build an 8in coil to a plan first and get that going. An 18 in coil would be good for depth on LARGE objects but would be foul on small objects at any depth. Do search here and learn all you can.
Best Regards Eric. -
The purpose of using Litz wire is to minimize eddy currents being generated in the coil wire itself and thus delaying the sample time until these eddy currents die out. The rule of thumb is to use Litz wire with individual strands of AWG31 or smaller to minimize the "eddy currents in the coil effect". If you are shooting for low delays for very small, quick decaying gold targets, then a smaller coil would be more effective. Also, if you make a solder connection between the coil wire and the coax cable in the coil housing, you risk picking up that solder joint as a small target at low delays. The way around this is to extent the coil wire up the coil shaft as a twisted pair. If the shaft is aluminum then you can secure the wire in the center of the shaft with a low dielectric constant foam as well as ground the metal shaft. Litz wire is usually only used up to about 3MHz to minimize the skin effect of the current running on the outside of the wire and not penetrating fully to the center due to the fast changing of the AC current or the pulse current. Even though square waves may be pulsing at lower frequencies in the KHz range the square waves contain harmonics of much higher frequencies and Litz wire will lower the apparent coil wire resistance to improve the current flow in the wire and prevent eddy currents at pulse current turn-off from lingering in the coil wire when you want to sample faster.Originally posted by MMTDETECTORS View Post
I hope this helps?
Joseph J. RogowskiComment
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