Power supply when mains voltage in unstable

hajj

Member
2009-11-23 10:04 am
I just scored a pair of populated F5 boards, and am in the process of building the power supply for the amp (much more complicated than the amp boards themselves!! ah the pleasures of DIY)

Over here in Lebanon, it is not uncommon to have the mains voltage fluctuate between 220 and 209 volts (and in extreme cases, down to 200V).
The F5 PS as per the F5 manual not being regulated, I was wondering what the effect would be on the amps performance and durability, and If there would be a need for a voltage regulator stage.

In case it should matter, I will be using a 1000 VA EI core transformer (custom wound, still cheaper than toroids over here) and will most probably have around 176,000 uf of capacitors.

Thanks

Nick
 
Does it ever rise above 220V? As you're getting it custom wound, it might be an option to wind them for a 210V or 215V "net" voltage. That might average out the differences. (little more, little less)

Rail voltage on the PASS F5 isn't very high (25V or so?) which would make the difference after the tranny something like 22,5V when it's 200V, and 25V when "normal"
getting the custom tranny, you could go for something like 24V to 26V? theoretically.

I don't think that would be a major problem. Still has to be rectified etc...

Regards,
Bert.
 

hajj

Member
2009-11-23 10:04 am
or use an AVR or/and UPS
There are also economical constraints, and a decent AVR or UPS will cost me more than the whole amp, this is why I though about a good regulator stage.

@Bert,
I like the solution you proposed, I'll try to get the guy to modify the secondaries to yield a higher voltage, and take it from there.

Thanks for your input guys, keep them coming

Regards

Nick