Hammond Power Transformer - 100v Tap for Bias?

[bw1985]

Hi all,

I’ve got the following Hammond power transformer id like to use with a Fender style power supply using the 50v bias circuit. Can I use the 100v purple wires and bring it down to 50v with a zener diode or voltage divider or something similar? Is that enough current?

Any advice if this will work and how to connect it would be great!

Thanks,
-BW

[Bloomfield]

Yes it looks like you'd be fine to use that winding for bias.

That transformer appears to have dual 100/110/120v primaries, so be careful with how you wire them.

I tried to look it up on Hammond's site, but couldn't find it as there is a digit or two missing from that torn corner. I don't recognise the 'H' prefix; possibly it is non-standard.
Most of their transformers have wiring diagrams on their website. http://hammondmfg.com/index.htm

[Chuck H]

You don't need to use a zener to regulate the winding voltage. You can just add a series resistor before the bias pot to increase the voltage division.

[The Dude]

^^^^^^^ Yes that. A simple voltage divider providing, basically, a reference voltage is all you need. There is very little current drawn from the bias supply.

[Chuck H]

There is very little current drawn from the bias supply.

^^^^^^^^^^^^^^^^^^^

This! Because there is insignificant current regulation isn't an issue. The voltage will be adequately constant with a simple divider.

Thank you Dude.