Re: Midas Board Power Supply

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

Hi David,
           Forgive me for not asking earlier:

On 11 Nov 2004, at 7:46, Tesla list wrote:

 > 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.

Can you infer from looking at the board what job they might have been
doing e.g. were they on the primary side in which case they might
have been part of an input filter or were they on the secondary side
in which case they may have been part of output filtering? If the
latter, the cores would most likely be iron powder in which case they
may have been subjected to excessively high ripple or AC currents,
something which causes iron powder cores to dissipate an awful lot of
power. Horribly speculative but trying to be helpful.

Malcolm