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bill ramsay
 
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Default low voltage high current heater supplies

dear all

I am playing with some 813's at the moment. I am trying to get the
heater supply sorted out.

the 813 needs 10v at 5 amps, the do glow v. bright when lit up.
pretty neat.

I have a breadboard amp going at the moment which someone else has
given me.

The current heater supply uses a 20 odd volt ac transformer, bridge
rectiifer, feeding a 2n3055 based regulator, thing is putting out
about 50watts in heat. as it is stereo there is 100w in heat being
generated.

whenever i model a 5 amp 10V heater supply in PSUD i get some really
whacky readings, ie.

28V transformer to feed 100,000u cap, with a 0.5ohm resistor, then
1000u cap into the tube. ie. 2 ohm load,

or am i missing something here, 28V ac seems a long way away from 10v
dc, or is this an artifact of the high current pulsing away and
charging the caps?

I wanted to build a dc supply that does not generate so much heat in
itself.

any thoughts, ideas etc. especially the printable ones would be
greatly appreciated.

kind regards

bill ramsay.