A 6.3vac/2A heater coil with CT

[pjd3]

Hello,

I really almost feel silly even asking about this but, a very good fellow tech where I work had me ruminating and second guessing myself.

On an Edcor Power transformer I have for an experimental amp board, this PT has two 6.3vac @ 4 amps and another 6.3vac @ 2 amps with a center tap.

Where I've never actually implemented a heater coil with its own center tap, (always installed the two 100 ohm resistors to ground), I thought it wouldn't hurt to make sure I'm getting the picture. Aren't these simply wired the same way as any heater coil and the dedicated CT just goes to a power ground? I would imagine the presence of this coil at the lesser current rating may be for preamp circuits where having a dedicated ground is better for noise issues, and the ground would sorta be bringing 3.14vac to one side of the tubes filament and 3.14 to the other side for a 6.3 differential.

Is this a way to think of it?

Thanks, want to make sure I'm not mixing myself up

Best,
PJD3

[sluckey]

I would not think about it like that. All the grounded center tap does is provide a ground reference to the filament circuit for the purpose of reducing filament hum. There is no current flow through the center tap and no voltage is being provided by the ground.