What does the "C/W" on this transformer data sheet stand for?

[John Smallberries]

Hi.

I have a data sheet for a Hammond 291BX (http://www.hammondmfg.com/pdf/EDB291BX.pdf), and there's a line in it that says the following:

Sec. Voltage (RMS) 660VCT @ 138mA C/W 50V TAP , 6.3V @ 3A / 5V @ 3A

This transformer has three secondary windings: 5 volts, 6.3 volts, and 660 volts. The 660-volt winding is center tapped and also has a 50-volt tap on it.

What does "C/W" stand for?

 

[techiesteve]

I've no idea, other than a guess. 'Complete with' to indicate its a tap on the 330-0-330V HT winding rather than a separate winding as is often the case. The 50V tap would typically be used to supply a negative bias to the control grids of the push pull output valves in an amplifier.

Steve

 

[(*steve*)]

Coupled with?

Reading the title, I was all prepared to say "degrees C per Watt" -- But I can assure you that in this case it's not!

 

[shrtrnd]

I don't know either, but I'll guess too:
The 660VCT, is 600 Volt Center Tap,
so I'd speculate 138mA C/W 50V TAP, might be 'Center/Wire'.
Probably, only the mfgr knows for sure.

 

[MP4BJI]

Transformer tap

Sounds as it is a tap for providing negative bias. If it is a tap, you can tell its connection by comparing the overall winding resistance and the resistances to the tap from each end of the winding.
Or you could just power it up and measure its voltage related to the other windings (be careful of the high voltages).
John