JIM HOLSONBACK wrote in a message to ALL:

 JH> Hello, ALL.

 JH> I have (or had) this "Auto Stereo Home Adapter" box, rated at
 JH> 115VAC, 12-14VDC, 3 amps continuous, 5 amps switching.

 JH> I ended up blowing it up - - I'll tell about that later.  Took it
 JH> apart, and the only thing in there which could possibly be a
 JH> rectifier is this lightbulb-looking thing, with 2 bare leads out of
 JH> the bottom of the glass, and wired to the circuit board.  I've seen
 JH> one of these before, now over 40 years ago, and it was on a little
 JH> 6V trickle charger, and I ended blowing that sucker up too, while I
 JH> was still in highschool. 

 JH> My questions - -
 JH> 1.  What the heck are these bulb things, and how much would a
 JH> replacement for the unit at hand cost?

It looks like a light bulb?  Clear glass?  Can you describe anything about
the innards?

 JH> 2.  How can a rectifier with only 2 leads give good enough DC to
 JH> run an auto stereo back in the home, without a lot of hum.

Good question!

 JH> 3. Should I pitch the thing, or could maybe some large diode or
 JH> diodes be added, which would make it useable again?

Cheap and simple -- get one of those 25A bridges from radio shack,  and
bolt that puppy to some metal to draw off heat.  I have one PS I built for
a bench supply,  uses a 4A transformer and a 3A regulator (TO-3 package), 
but the original "6A" rectifier didn't last.  So I put one of
those heavier-duty units in there.  I shouldn't ever really expect RS stuff
to meet their specs,  but it's awfully convenient sometimes.  :-)

 JH> FWIW, in desperation, after probs with the riding mower, I used
 JH> this unit for a battery charger.  It worked OK, and put some charge
 JH> on that there lead acid battery, but I blew it up and 'let some
 JH> smoke out" when I tried to crank the mower while this makeshift
 JH> "charger" was still attached.

Heh.

I have a number of battery chargers around here that have bad diodes, 
probably from similar causes.  Though a number of them seem to be rated for
surges of a LOT of amps for fairly short periods of time (30 seconds or
whatever).

Speaking of battery chargers,  this reminds me of one that my grandfather
used to have.  The rectifier in that one did look like a light bulb,  only
it also had a wire coming out of the top.  That was a mercury vapor
rectifier,  and I haven't seen one of those since I was a kid.

If that's what it is,  good luck in finding a replacement.

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