On 05 Jul 2005 18:50:57 -0400 Sam Goldwasser
wrote:

"geoff smith" writes:

I am seeking advice on the replacement of the moving contact on a 2 amp
Variac.The original "Brush" appears to be made from Graphite and is about
4mm in diameter.
The makers were Zenith Electric London (RIP).

I'd simply file down a motor brush to fit. It's not critical.
Makes a mess but less time and effort than trying to find an exact
raplcement. One I did on a power supply 25 years ago is still going
strong.

I don't know about his model, but many of these use a brush which
consists of a carbon brush brazed to a brass holder, or a carbon brush
with a pigtail embedded.

The first is impossible to duplicate, while the second requires
slightly different starting materials.

Or does someone know how to braze to carbon?

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Jim Adney
Madison, WI 53711 USA
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