Re: Midas Board Power Supply

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Harold Weiss" <hweiss-at-new.rr-dot-com> 

Hi Malcolm,

The xfmrs looked to be about the same size as the gate drive xfmrs on the
Plasmasonic.  They were about 1-1 1/4" in diameter and 5/8"wide, and looked
to be bifilar wound with about 20 ga wire.  The main supply was a switching
type which supplies the +48, +/-18, +5V supplies for the mixing console. All
other toroidial cores in the unit except for a power xfmr all had single
windings, which would mean that they were chokes.  The board that had these
xfmrs on it was totally engulfed and the traces were burned off so I
couldn't trace exactly what they went to.  It does seem strange that they
weren't mounted to the regulator board.  All the fuses stayed intact and
were of the proper size.  The only other thing that they might have been
used for is sensing a supply failure.

David E Weiss

 > Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz>
 >
 > Hi David,
 >
 > Were the transformers in question power transformers or gate drive or
 > doing some other job? At what frequency would they have been running?
 > Sorry for the questions - I know nothing about that particular supply.
 > I presume the rectifiers were OK. A short on the secondary side (if
 > they are power transformers should have smoked the fuse/s on the
 > primary side if nothing else.
 >
 > Malcolm
 >
 >
 >