Will this trim pot work here?

[rockon1]

I would like to use a trim pot in place of the 120K resistor in the bias supply in the schematic below to make my bias adjustable. At the moment I have a 100K in the amp and it works great. The trim pot is only rated for 300vdc max. The voltage before the diode is 330vac. Thanks Bob

[olddawg]

[QUOTE=rockon1;199876]I would like to use a trim pot in place of the 120K resistor in the bias supply in the schematic below to make my bias adjustable. At the moment I have a 100K in the amp and it works great. The trim pot is only rated for 300vdc max. The voltage before the diode is 330vac. Thanks Bo[QUOTE]

Put a resistor, say 60K ohms in series with the trim pot. That will recuce the voltage across the pot by about half.

[rockon1]

[QUOTE=olddawg;199878][QUOTE=rockon1;199876]I would like to use a trim pot in place of the 120K resistor in the bias supply in the schematic below to make my bias adjustable. At the moment I have a 100K in the amp and it works great. The trim pot is only rated for 300vdc max. The voltage before the diode is 330vac. Thanks Bob

Put a resistor, say 60K ohms in series with the trim pot. That will recuce the voltage across the pot by about half.

Oops ,my mistake. It will be used with a 22K "failsafe" resistor. Is that enough?

.............................I just checked and since the pot goes to basically zero theres no reason not to use a 60k -Thanks again Bob

[rockon1]

Still thinking...If the 330 Vac going to the diode is being 1/2 wave rectified then going to the resistor I wish to replace then its only going to see at most 1/2 of that in Vdc or 115vdc that is?

Cmon guys I know this is childs play for you. Bob