Rewinding a variac

[retailer]

I've had one of those weeks where there seems to be and endless list of things to do and places to go - none of it for me, so I have not been able to spend any more time on the rewind, I did though go through the old wire I pulled off and checked it with my digital calipers it has not been flattened at the point where the graphite slider picks up the current - it is thinner when measured across the point of contact so for this variac at least I doubt it was flattened, I don't know about other variacs though, possibly they are.

[Diabolical Artificer]

"I've had one of those weeks" We all get em. My variac does have flattened wire but it's a big 8A jobbie, so bigger gauge wire which would cause a bumpy surface for the carbon brush. Maybe it's not needed on smaller variacs.

Andy.

[ajgriff]

I'm guessing that this is an early 1A Lyons Variac ™ (licensed by the US company General Radio for production in Australia) with a cylindrical brush so it probably wouldn't have had flattened windings or plating. Later models like my 3A version had the Duratrak contact surface coating and rectangular brushes although I believe that some of the smaller Duratrak models also had cylindrical brushes.

Alan