WAD Psu3 replacement Board Build

[colin.hepburn]

Hi all
l now have the new replacement PSU and full manual ready to go soon
Some questions thought to start with
1. The no-load Voltage for PSU3 at C1 is 410v and on PSU2 its 363vat C1 with same TX 0v-270 volts 60mA assuming main voltage difference seems odd to me

2. Change out the 1k R4 for 22k add the 200-volt Zenner and C3 100uf for the CF pre-HT 200volts
3. add back in C4. 100uf for phono HT 250 volts as was before on the psu2.

I was just going to swap over the component to the new board but with the higher voltage the main 100uf Caps are only rated for 400 volts so decided to just use all new parts with the exception of the two bridge rectifiers as they were upgraded off the PSU2 when we build it last time
For know thank all
Colin

[Richard]

Hi Col,
Can you meter the TX secondary red/black on both for 270V AC?

[colin.hepburn]

Originally Posted by Richard

Hi Col,
Can you meter the TX secondary red/black on both for 270V AC?

Richard
yes I will come back on that need to disconnect the TX from the old board to check it

[colin.hepburn]

Originally Posted by colin.hepburn

Richard
yes I will come back on that need to disconnect the TX from the old board to check it

OK, Richard, I get 279 volts AC with wall main At 246volts

[Richard]

Are you using just 1 TX connected to both PSU2 and 3 pcbs Col? I thought you had 2 and maybe one TX was incorrect voltage.


If the pcbs were both tested off the same single TX PSU2 looks about right so just hook up PSU3 and work on that. I can't see an obvious reason for it being so high, is the bridge correct, they are separate diodes I think?

[colin.hepburn]

Hi Richard
Sorry the psu3 in not build yet I was just inquiring why the voltage of the PSU 3 was higher At C1 410volt than C1 on the psu2 schematic has a lower voltage with same TX used on both comparing looking at both schematics I Was just checking on this before ordering new higher voltage Caps for C1/2/3/4