Newbie: Which winding for relay?

[timrobertson100]

Hi folks

I’m doing my first relay channel switched amp and have a newbie question.

I’m using a Tube Town 18W extended PT with:

Primary: 0-120V / 0-110V-120V @ 50Hz
Sec. 1: 600 V C.T. @ 100 mA
Sec. 2: 6,3 V C.T. @ 3,2 A
Sec. 3: 6,3 V @ 2A
Sec. 4: 8V @ 2A

I’ve got bits here to do a Dumble #124 style relay power supply - a voltage doubler into a 12V regulator to 12v relay.

Would it be better to feed the doubler circuit with the 6,3V or 8V winding please?

Without opening a can of worms, can someone confirm it’s ok to tie the regulator common ground to chassis ground please, given it isn’t a centre tapped winding?

Thank you very much

[martin manning]

I'd go with 6.3V, if you have an extra. The doubler will get you enough voltage for the 12 regulator, so no sense generating any excess just to turn it into heat. Connect regulator ground to ground as shown in #124 schematic below.

[bepone]

if is only relay powered from this doubler, there is no heat anywhere, any doubler is ok.

[timrobertson100]

Thank you both - the 6.3 it is