ST-35 Replacement Transformer
Posted:
Sat Sep 29, 2012 6:07 amby johnf
My Trafomatic Mains tranny seems to have died. Can anyone tell me whether EdcorXPWR066 240V primary has enough 6.3V / 5V for this circuit with a GZ34 rectifier.
I don't think Trafomatic will make me, or supply me with, a replacement as they seem to no longer deal with individuals. Whatever I use is going to mess up the layout of my top plate.
http://s1062.photobucket.com/albums/t484/jhdrum/
Any info appreciated
Posted:
Sat Sep 29, 2012 6:30 amby Geek
Hi,
The XPWR005 has the same secondary ratings as the PA-774:
https://edcorusa.com/p/977/xpwr005_120-240
A little Hammond 5V @ 2A can handle the GZ34.
Cheers!
Posted:
Sat Sep 29, 2012 5:45 pmby Shannon Parks
Edcor XPWR066-240: You’ll be low of your target B+ -basically your rectifier voltage drop. Not a huge problem.
Edcor XPWR002-240: Maybe a better option. You should opt for a large voltage drop rectifier. Also use an IRCL to tame high B+ at turn on before the outputs warm up (for the caps sake).
Edcor XPWR124-240: Probably will run warm (guessing 55-60C), but otherwise exactly what you need (note 2A for rectifier).
Shannon
Edcor replacement
Posted:
Sun Sep 30, 2012 2:53 amby johnf
Many thanks.
The Trafomatic was specified at 300-0-300V and did work fine
My main concern was that the 6.3V 4Amp secondary was too low on the Edcor.
What rectifier would lower the B+ with the XPWR-002. Do you mean using something other than a GZ34?
Thanks again
Posted:
Sun Sep 30, 2012 4:57 amby Shannon Parks
You'll only be using around 3.64A, so you are fine with the 066.
With the 002, you'd need something with a larger voltage drop than a GZ34, like a 5U4. Since that is not a slow warm-up rectifier like the GZ34, you'd need the IRCL to limit peak voltages at turn on.
Shannon