TU56/TC11 restoration - VARIAC question

[Eric Smith]

Ashley wrote:
> I do not own a variac, so I will need to get one of these to
> properly reform the TU56 capacitors.  I see several different varieties
> on eBay.  What would I need exactly?

If you're talking about the motor run capacitors, I don't think powering
the TU56 up on a variac will reform them, because they're not wired in
the same manner as power supply filter capacitors.  I strongly recommend
reforming them separately, for which you don't need a variac, but just a
DC power supply and a series resistor (or a DC power supply with adjustable
current limit).

If you do buy a variac, be forewarned that it is NOT an isolation
transform.  It is an adjustable autotransformer, which means that the
primary and secondary are actually the same winding, and there is
no electrical isolation between the input and output.  Therefore you
have to be just as careful with things powered from a variac as with
things powered directly by line voltage.

Eric