PSU 3 BitsHelp Pls

[Richard]

Hi Martin,

1. Yes they'll be fine 100 or 150uF and 400 or 450V, check the cap dimensions will fit the pcb and consider filling all 4 spaces with them for improved smoothing

2. Depends which reg and pcb you have. Mine was on old pcb and uses a fixed 5V reg with 2 diodes to raise ground to give 6.3V. When Peter did the later pcb he used adjustable version of that reg and 2 resitors to set 6.3V. So check through the WD instructions and the data sheet for the reg you are using and wire the pinouts to diodes or resitors accordingly.

Mine looks like this for example with the ally case used as heatsink, and before I later fitted 4 smoothing caps,

[Pingushome]

Thanks Richard,
I have the 3.1 version psu board which has the adjustable voltage reg and the zener diode. I am using a LM1084 and the 5watt zener as advised in the CF conversion on the forum as I am also building a PRE 2 CF. All the values of the other bits are as version 3.0.
BTW where is R7 and what value?
Martin

[Pingushome]

Hi Richard,
To continue the above. Am I right in thinking that as I have both space for the resisters for the adj voltage reg and zener diode I can use either. ie adjust reg and resisters or fixed reg (a la psu2 and mods as you have used) and zener? in the latter case I need to use links in place of R8/R9?.
I think there was a cd of all the projects (which i have in printed form) but it is no longer available if I can get a copy from some where that may be a help. (fleabay I guess}
Thanks
Martin

[Richard]

Hi Martin,

Mine is PSU3 but I don't know which version pcb. PSU3 was originally done to use 78S05 reg. We moved to low dropout LM1084 to avoid dropout on full load/low mains.

The pcb was later done to PSU3 V3 which will have adjustable reg using resistors.

Hence why you need to check your pcb tracks and be sure you wire the reg with correct pinout.

The CF mod was done based on PSU2 originally so you'll have to interpret it to your pcb.

What you have will work fine once you check the spec and track the circuit.

It sounds as though yours is like mine in the photo, see if it has those 2 diodes in the photo which are from the first PSU3 version and for use with fixed 5V reg. See too how my pinouts are crossed over by the coloured wires from the 78S05 originally intended.

If you send me your email I have PSU2, PSU3 and later PSU3 circuits and LM1084 data sheet so you will be able to sort it

[Pingushome]

Hi Richard,
You have a PM

[Richard]

Got it and replied Martin