|[AMRadio] Step Start|
jack at schmidling.com
Mon Dec 11 12:20:21 EST 2006
I just ordered a trans for my pwsup and need to work around the hi/low
step start designed into it. It uses the 220 line to provide 110 or 220
to the transformer. The new one is 110 so I do not have this option.
I plan to reroute the hi/low switch to a resistor or better yet a light
bulb to reduce in input voltage at start up.
The original was limited to 110v but with a resistor, I can provide any
start up voltage I want so I need some help figuring out what resistance
would be best.
There is a time delay relay that precludes putting any voltage on the
primary for one minute to allow the tubes to warm up so I presume the
hi/lo is to reduce the surge upon charging up the caps.
This is a choke input with two 4 mf in parallel across the output and
somewhere it seemed to imply that the step start was only needed for cap
As far as I can get with the heavy math, it seems like the resistor
required would only be a few watts as it is only dealing with the 100k
bleeder as a load.
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