Voltage Multipliers

Thread Starter


Joined Nov 2, 2010
Hi, I collect antique radios mostly vacuum tube tech, RCA and Zenith radios are my favorite. Building battery packs can be a problem the weight factor and lack of room, too many 9 volt batteries.

Looking for a simple way to build a circuit using a few 9 volt batteries to generate 45 to 90 volts DC, with a low current required. Circuit must be regulated. Would be nice ....

Old battery packs used 9 volts high current for the tube filaments and up to 90 volts low current for plate voltage.

Thank you for any help.



Joined Jul 17, 2007
Check out Ronald Dekker's great page on flyback converters:

Reduce R4 to ~100k or less.
You could use an IRF730 for T2, even an IRF510 might work if you stay below 100v. A 2N2222/PN2222 would for T1.
D1 needs to be a fast-recovery diode, 200V would be fine for you. A 1N400x series won't be fast enough.
The item below R7 is a neon lamp. Radio Shack carries 120v neon indicators that already have the resistor built-in, which would work for your 90v supply.

You really don't want to run from 9v "transistor" batteries though; they won't last long at all. If you used 8 D-cells in series, they'd last quite a while. Better yet, get a "wall wart" plug supply, and power it from that - never buy batteries again.