Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!pasteur!ames!elroy!peregrine!ccicpg!cci632!rdi
From: rdi@cci632.UUCP (Rick Inzero)
Newsgroups: sci.electronics
Subject: Whatizzit?  ("Battery Booster")
Summary: Well, it's from around 1959...
Message-ID: <27792@cci632.UUCP>
Date: 10 Apr 89 19:14:59 GMT
Reply-To: rdi@ccird3.UUCP (Rick Inzero)
Distribution: na
Organization: CCI, Communications Systems Division, Rochester, NY
Lines: 54

I was just given a car "battery charger" (at least that's what I 
was told).  Anyway, I can't figure out if/how it works, since it's pretty old, 
and the technology pre-dates me.  When I plug it in (with both output leads
unconnected- just floating with no load), I get only AC out, *no* DC, so I 
don't think it's in working order, but I can't be sure... opening up the 
metal case, I see only 3 components:  a transformer, a current-sensing 
shutoff device rated at 10 Amps (to protect against the output leads 
shorting), and one really mystifying component... it's a flat 3" square of 
metal, insulated from the box by insulating paper, in the center is a 2" disc 
of brass, with a brass hole thru the middle, 1" brown insulating disks on top 
and bottom, and a bolt passing thru the hole to hold the metal device in place 
plus connect the center brass hole to the metal case.  Sprayed on the surface 
between the metal square and the brass disc seems to be a granular grey 
substance, and it is NOT in electrical contact with the metal square.
The granular surface IS electrically connected to the 2" brass disc.
Is this metal/brass component some archaic diode (rectifier) that is no longer 
working up to par?  To my continuity tester, it acts like a diode.  Testing 
w/between 1 ohm and 4K ohm resistive loads on the output terminals caused 
a maximum of about 3-4V *DC* to be produced.  Pretty useless for charging
a car battery.
Could it be that this "battery booster" box will start to function (produce DC) 
only in circuit, i.e. when connected across a 12V lead/acid car battery?  
I sure don't want to just connect it to a battery and find out!  
Here's all the info printed on the case:
	Battery Booster
	Model 421B
	115v  60 cycles
	Output 2-4 Amps Appx.
	Automatic Reset Fuse
	Electric Service Systems, Inc.
	Minneapolis, Minnesota  
Unfortunatly, no output VOLTAGE is specified, so I don't even know if
it's meant to be used with 12V or 6V car batteries.
The metal "mystery component" has an inspection type stamp on it that
says "Syntron    Aug 3 1959" and the characters "L8" and "SD 1081".

I'd sure like to see this working, hopefully without gutting it and 
starting over with new modern components.  Hopefully, one of you can tell me
that it's working properly already, and just needs a load... 
So is (was?) it truly a battery charger or merely a booster or what?

Thanks for any advice you may offer...

Rick


---
Rick Inzero					rochester!cci632!rdi
Computer Consoles Inc. (CCI)			uunet!ccicpg!cci632!rdi
Rochester, NY					uunet!rlgvax!cci632!rdi


"Your grandmother never, ever called me stupid.  
	She always called me 'pinhead'." -Jimmy Stewart in 1988 Campbells Soup