Uses for TV brightner transformers

[wa2ise]

Most vintage CRT brightners used little 60Hz power transformers that convert 6.3VAC to around 9VAC. More accurately, they are autoformers. Okay, we avoid these things like the plague on CRTs, so what else could we do with these? I mean, in electronics work Well, say you have some 8.4V heater tubes but you need its 6.3V equivalent. One of these autoformers will get you there. Yeah, how often does that come up...

Another use is in a series string set where you need an 8.4V heater tube, and all you have is its 6.3V equivalent. Put the string line into the 8.4VAC connection, and the tube on the 6.3V connection, and both to the other side of the transformer, and the other end of the string. The tube should be the same heater power as the original tube.

The series/parallel ones usually can produce about 12VAC from one end of its winding to the other, with taps at around 6.3 and 8V.