I am not an Electrical Engineer.
I have no formal training in electronics.
I do not guarantee the accuracy of any of
the information/drawings/pictures/etc.
Use at your own risk.
I take no responsibility, or liability,
for anything.
This is for my model version (R3?). Yours may be different, of course.
The output socket has been removed from my board.
I added the short strand of white wire for a modification. It is not
part of the original device. You may notice other modifications.
I believe the circuit is a center tapped full wave rectifier operation.
Both of the two parallel windings supply 12.78VAC and are referenced
to Center GND. However, the exact arrangement of the Pin Legs of the
Secondary Windings was not investigated. I would think that these
windings would have to be wired out of phase, to accommodate the use
of just two rectifying diodes (SR1660 is a dual diode.)
However, I am not certain. If someone wants to explain the complete
operation of the circuit, that would be helpful and wonderful.
For both fuses
Brand = "bel" (?)
5TT5A - 125V
C1 = 4700uF/25V
Some lettering on the board =
PCB76UV-01
WL UR(INVERTED) 94 V0V30
I am posting this information, solely as a "good Samaritan," as I
was unable to find much information about the unit on-line.
I hope it helps someone.




