George, pertaining to:
>I'm in the process of building a 3-500 amp from the dregs of
someone elses earlier project. I have the power supply built, but the
power transformer I used was designed for 220 VAC nominal rather than
the 240 (plus) that I have at my outlet.
The problem is that with a standard capacitor input filter my
no-load voltage is around 4300 VDC, which is a bit high for a pair of
3-500s.
Using a variac I have determined that 220 VAC gives me 4000
VDC no load. With the voltage dropping to 3400 under load.
Short of using a variac is there any practical way to lower
the primary voltage?<
If you happen to have a good quality 20-volt @ 20-amp transformer handy, you
can wire its secondary in series with the primary of the plate transformer,
phased for "bucking" the voltage by 20-volts, resulting in 220-volts
effective at the plate transformer primary.
73, K6XK
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|