On 17 jul 2011, at 16:48, Andrew Jury wrote:
> If you can’t work this out for yourself then I would be very carefully
> poking around on the primary side of the mains supply!! However, as long as
> you promise not to sue anyone if it goes wrong then the 50VA transformer
> with 2 x 25v secondary windings might be what you are looking for.
Are you sure about the 2 x 25 V? In my schematic there are some caps behind the rectifier which are only 35 V. (25 V x sqrt(2) - 0.7 V diode loss = 34.7 V.) And with less load or over voltage on the input the transformer output could be even 10 % or 20 % higher and you would blow the caps.
My guess is you would need only 2 x 16 V, 40..50 VA. Anybody here actually measured the output voltage of the transformer?
By the way, if you open up the Polysix, it might make sense to recap the power supply board anyway. And make sure to check the battery. But you probably know that. :-)
Kind regards,
Ben