Old synth & variac, wasRe: FGTH, was Re: [sdiy] "Foot pedal"?!

[Ken Stone]

Either run it for very short periods at first. on for 1 minute, off for 5,
or fire it up with a 100W light bulb in series with the mains. If the
current draw is too severe, the lamp will light, limiting the current.

Ken



>----- Original Message ----- 
>From: "john mahoney"
>> Should a keyboard that's been asleep for 2 decades be brought back up with
>a
>> variac?
>> --
>I would think not, because the rectifiers & main caps are driving
>regulators, and
>the system as a whole isn't designed to run with an odd input.
>In fact, with the input under-run, you will be sending odd unsmoothed
>voltages to various parts,
>with possible problems with analog and digital circuit interactions
>(sometimes stuff is designed
>in such a way that it needs some power rails to be always higher than
>another, or to reach
>operting voltage in a particular order).
>
>I hope that someone with more experience than I have will answer as well,
>but personally
>I don't think it is ever a good idea to run anything outside its design
>specs, even on the low
>side.
>
>paul perry (Frostwave analog fx) Melbourne Australia
>
>
_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au or sasami at cgs.synth.net
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>