[Prev][Next][Index][Thread]
RE: RF chokes
The use of chokes in NST protection networks is no longer recommended.
Chokes tend to ring at some frequency with the same amplitude as the tank
oscillations that you are trying to filter out. Instead, use R-C networks,
which have been described and discussed many times on this List.
As far as your particular chokes, there are several problems. The choke
will develop several tens of kV across it in operation. The small size of
your cores (toroids?) will make it difficult to insulate end-to-end. Also,
ferrite is not an insulator at the voltages involved, so thick insulation is
required between the wire and core. And you are correct about saturation.
Such a small core will saturate with very little current, the result being
diminished inductance.
Regards, Gary Lau
Waltham, MA USA
-----Original Message-----
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Thursday, April 27, 2000 7:12 PM
To: tesla-at-pupman-dot-com
Subject: RF chokes
Original Poster: "Alexander Rice" <alexjrice-at-hotmail-dot-com>
I spoke to my electronics teacher today regarding ways to protect my
transformer and told him i needed a 2mH inductor. He recommende winding them
on
ferrite cores that were little more than 3/4" across, is this possible, they
measured uo right but with only 30 turns and on such a small core are they
going to saturate or do something else undesirable like melt or catch fire,
the
wire is about 20 swg so fairly heavy