RE- EMI Shield Beads
From: Robert Michaels[SMTP:robert.michaels-at-online.sme-dot-org]
Sent: Thursday, September 11, 1997 5:01 AM
Subject: RE- EMI Shield Beads
Ferrite beads can be very effective in rf absorption and are
used routinely for such purposes.
As said in the literature you found, they are effective only
at high frequencies. (Have you made any 25-MHz. Tesla coils
- - - - - - - -
THHN is machine wire, not house wire. I =strongly= recommend
against using it in any sort of coil since its slick Nylon
coating is very stiff, making it hard to wind and quite
resistant to small-radius bending.
If you are intent on using machine wire, I recommend MTW
instead. It is soft and flexible and decidedly cheaper
TL>Sent: Wednesday, September 10, 1997 1:55 PM
TL>While looking threw an industrial electronic catalog at work today I noticed
TL>something called EMI shield beads. It had a picture and a small amount of
TL>information about this things. The informtion said.
TL>EMI shield beads. These 6 hole ferrite beads wound with various
TL>offer very high impedance in a small package. Maximum suppression is obtain
TL>between 25 and 250 MHz. 1.5" x 30 mm. 100 pack $17.12, 25 or more packs
TL>It does not say what value can be obtained. I was thinking these might make
TL>good chokes for a TC wound with #14 THHN house wire. Is anyone familiar wit