Metropoulos Forum

Hello

The Voltage on my PT Plates is a little bit high. It`s 500 Volts. How can I bring it down a little?


Thanks

There's a ton of ways. One simple way is to put a high power Zener in between the pt center tap and ground.

The voltage will drop by the value of the Zener. So, a 50v Zener will drop it by 50 volts.

rsi wrote:There's a ton of ways. One simple way is to put a high power Zener in between the pt center tap and ground.

The voltage will drop by the value of the Zener. So, a 50v Zener will drop it by 50 volts.

Assuming the wattage will take it - thats gonna be a big honkin' zener to drop 50v off 500v.

Variac

What is the amp, what tubes are you using?
Have you measured your heater voltages too (if they are high then changing the PT primary tap setting might be a simple option for a little lower (but not 50v tho' )