28 Dec 2002, 23:13, JIM HOLSONBACK (1:123/140), wrote to JASEN BETTS:

Hi JIM.

 JH> OK, here's diagram of the secondary side of the transformer.  I 
 JH> moved the Center Tap part over to the right, for clarity.  Trafo is 
 JH> 15-0-15 VAC.

 JH> SCHEMATIC - "AUTO Stereo Home Adapter - Internal Circuit Breaker
 JH>           12-14VDC 3A continuous, 5A switching"
 JH>                  +12V  Pos Out                    Neg Out
 JH>                            |                          |
 JH>                            |                          |
 JH>                     'MYSTERY BULB '                   |
 JH>                            |        4000 mfd          |
 JH>                            |       +     -            |
 JH>                            |---------| |--------------|
 JH>                            |                          |
 JH>                            |                          |
 JH>               |-----MP-----|----MP-----|              |
 JH>               |                        |              |
 JH>               |                        |              |
 JH>               |                        |              |
 JH>             15VAC                     15VAC         CenterTap

 JH> The "MP" are those mystery parts, now both burned up, and
completely 
 JH> into two pieces.  I don't think they could have been 12V 3A  
 JH> bead-shaped diodes, because they are only about the same size a maybe 
 JH> 1/4 Watt resistors, and I think this unit was built before the time 
 JH> of bead-shaped diodes..

 JH> I don't understand this circuit at all, but afaict, that "mystery 
 JH> bulb" is the only thing in there which could possibly be a 
 JH> "rectifier".  I don't see anything which could be called
a 'circuit 
 JH> breaker', unless it is those two (now blown) mystery parts.

The 'giveaway!'  

The bulb is definitely the "Internal Circuit Breaker" described
on the title line.  The two "MP"s were likely 1N4001 diodes, each
carrying a successive half-wave of the 15V, for a low ripple output, and
that "extra" rating of "5A Switching" would have been
carried by the filter capacitor.

Nearly identical to Jasen's diagram!  Wire in two little 3A diodes in the
direction of Jasen's diagram, and you should be back in business!

If the bulb fails to give you zero Ohms, put a 5A fuse in it's place, or
mount a little Push-to-Reset breaker on the box.


     Good luck...  M.

--- Msged/386 TE 06 (pre)