Xref: utzoo sci.energy:555 sci.electronics:7509 sci.med:11755
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!amdcad!diablo!phil
From: phil@diablo.amd.com (Phil Ngai)
Newsgroups: sci.energy,sci.electronics,sci.med
Subject: Re: Electric cars?  Start with wheelchairs.
Message-ID: <26906@amdcad.AMD.COM>
Date: 23 Aug 89 02:44:22 GMT
References: <3659@internal.Apple.COM> <1526@cbnewsl.ATT.COM> <169@nwnexus.WA.COM> <3736@internal.Apple.COM>
Sender: news@amdcad.AMD.COM
Reply-To: phil@diablo.AMD.COM (Phil Ngai)
Organization: Advanced Micro Devices, Inc. Sunnyvale CA
Lines: 20

In article <3736@internal.Apple.COM> ems@Apple.COM (Mike Smith) writes:
|The system is, indeed, 24 VDC.  Two twelve volt deep cycle leadacid 
|batteries in series.  There is a 'funny plug' that connects them to
|the control harness in series.  It also connects them to the home
|charger in parallel, but not at the same time ...
|
|The 'dream charger' would be a DC to DC converter (with an AC -> DC
|rectifier front end for household use) that used switching circuitry
|to reduce heat generation and reduce transformer size to the small side.
|The whole thing sealed in a waterproof metal enclosure with weatherproof
|cables.  Then it could run from [{any Hz.}110vac,220vac,12vdc,24vdc,etc. ...)

Why make it so complicated? Seems like a straightforward application
of relays to switch the batteries from the operating 24 volt series
mode to a charging 12 volt parallel mode combined with a cheap trickle
charger from an auto parts store would do the trick. (excepting the
220 thing.)
--
Phil Ngai, phil@diablo.amd.com		{uunet,decwrl,ucbvax}!amdcad!phil
"Today surgeons are highly respected but they were once just grave robbers."