Positive voltage converter.

[danial stocks]

>
> >>>I seen some commercial synths start with double inside.. doepfer 404 
>for example, I think this has doubler inside from mem..<<<
>
>yeah, but don't doepfer psu's go wrong?  :-)
>
Well I fixed one... only the caps electros main filter caps needed 
changing.. also a conversion to 240V... I think the actual cause of the 
fault is that someone actually plugged the then 110 V unit into the 240.. so 
under the circumstances, I'd regard it as a pretty reasonble design to only 
lose 2 50 cent caps on a prolonged 100% overvoltage..



>what's wrong with the old fashioned two secondary windings (or a ct), two 
>bridges, two big C's, some little c's and a pair of regs? surely the last 
>thing you want to waste time redesigning is the power supply......
Well, almost the same, one winding 2 diodes, 2 big C's, some little C's and 
a pair of regs.. keeps the real estate small for when space is an issue.. or 
the lack of dual winding or +/- plugpacks also can be a bit of an problem at 
times...
this doubler technique has been around at least as long as semiconductor 
diodes have and is known to work well .. no redesign necessary ;)

Cheers,
Dan
>d.
>
>
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