Hello All,

I'm looking for a voltage doubler circuit, that doesn't use a transformer, to convert standard 220 AC line voltage to approximately 400 volts DC @ 250 mA for the plate supply of the vacuum tubes of a ham shortwave transmitter. I would appreciate it if anyone could direct me to a source for such a circuit.

Many thanks,

Brian Burns

 

Hello Brian,

I'm sorry, but we cannot help you with that particular request. Although our primary focus is electronics, our overriding concern is safety. Discussion of "transformer-less" supplies is specifically prohibited by our Terms of Service.

In order for a power supply to be considered safe, it must provide galvanic isolation from mains power, which means an inductive coupling of some sort - a standard 50/60Hz transformer, or a broadband transformer as in a switching power supply.

I suggest that you pursue a switching power supply design rather than a traditional 50/60Hz transformer. I know these transformers have become prohibitively expensive since tubes have largely fallen out of favor, and the cost of copper/shipping have gone up considerably.