> This one is for the High Voltage Power Supply Guru's. I have a transformer
> thats secondary is 1100 volts.Theoretically a full wave doubler would give
> me 2.8x equaling 3080 volts. Is this the real voltage that I will see?
With no load, probably.
> transformer by the way is rated at 750 mils DC., 1100 and 1300 volt taps.
> The reason I need to know is I hoped to feed 4-572B tubes with it. Most
> specs on the 572B call for a maximum of 2700 volts, with the average being
> 2500 to 2600 volts. Can I use the theoretical 3080 in hopes that it really
> won't be that high or am I asking for trouble? Any suggestions short of a
> variac would really be appreciated. Thanks in advance.
First, the transformers peak current is much higher in a capacitor
input supply than in a choke input supply. That means you must
have overkill on the winding wire sizes, or voltage regulation will be
poor.
Second, in a full wave doubler everything is twice as bad. The
current peak is at least twice as high as in the standard full-wave
rectifier.
Third, the transformer you have is designed for .75 amps times the
dc voltage with the rectifier system they expected. The transformer
probably has less-than-a-kilowatt transformer core rating. Probably
OK if you plan on running about a kilowatt or so INPUT in the
rectifier configuration they planned on.
Fourth, watch what 572B's you buy. The Russian 572B's are lousy
for voltage breakdown and out-gassing. That's the last tube you
ever want to run near the HV upper limit under no-load or light-load
operating conditions.
Some Chinese tubes are good, as are the Cetron 572's.
73, Tom W8JI
w8ji@contesting.com
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