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From: gettys@yacht.enet.dec.com (Bob Gettys)
Newsgroups: comp.sys.laptops
Subject: Re: Can Laptops be powered from Car Batteries?
Message-ID: <22589@shlump.lkg.dec.com>
Date: 10 May 91 15:15:52 GMT
References: <18820001@hpspdra.spd.HP.COM>
Sender: newsdaemon@shlump.lkg.dec.com
Reply-To: gettys@yacht.enet.dec.com (Bob Gettys)
Organization: Digital Equipment Corporation
Lines: 15


	A lot of laptop manufacturers sell car adaptor cords. For example, my Toshiba T1000LE
has a cord available from Toshiba. The Laptop runs on 12v and the cord allows you to plug it into
a cigarette lighter plug (cost - about $100). I questioned the cost, untill I looked at what I was
buying - it's a full DC-DC converter  designed to fully isolate you from the vagries of the car
electrical system and charge the laptop battery (which is 12v) when the car output is below that
of the ni-cad.

	If your laptop ac supply puts out less than about 10 volts, it would be fairly easy to 
build a 12v to "x"volt  voltage regulator with appropriate filtering and overvoltage and spike 
protection. If you don't feel comfortable with that, I have seen advertised small dc to ac (115v
output) converters designed just for this purpose. You plug it into the 12v source, the laptop
ac adaptor into it, and the laptop into the normal power supply.

	/s/	Bob Gettys