From: Chris Carlen
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Subject: Gate drive transformer ferrite?
Date: Fri, 18 Oct 2002 23:51:57 GMT
NNTP-Posting-Date: Fri, 18 Oct 2002 16:51:57 PDT
I'm planning on accumulating a small stock of Fair-Rite 78 material
cores for making SMPS inductors and transformers. Ugh! There are so
I am also interested in making some FET gate drive transformers for
various purposes, one possibly being a PWM motor driver (I know there
are chips to do this, but I want to perform experiments my way), and
another, the more important application, is a gate drive transformer for
a solid state tesla coil in the 100kHz-500kHz range.
It seems that 78 material is used for power applications, up to about
200kHz. The 61 material is the highest frequency material, but has
quite low permeability. It seems that I would want a high permeability
for a pulse/broadband transformer, but the high permeability stuff gets
very lossy above a few 100kHz. I'm thinking that it needs to be useable
into a few MHz in order to preserve fast risetimes into a FET gate, to
avoid sluggish turnon/turnoff. I venturing here a bit. Am I in the
Should I just try a 78 core for the gate drivers too? What do other
folks use? I'm a bit vague on parameters right now, but in about
another few weeks I will be knee deep in magnetic field physics in my
Electromagnetics course, so I will re-familiarize myself with all the
math that will make sense of this stuff. After that perhaps "magnetics
design" won't be so mysterious anymore.
Thanks for comments.
Christopher R. Carlen
Suse 7.3 Linux 2.4.10