Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!udel!rochester!pt.cs.cmu.edu!o.gp.cs.cmu.edu!andrew.cmu.edu!da0g+ From: da0g+@andrew.cmu.edu (David Apfelbaum) Newsgroups: comp.sys.zenith Subject: Re: Questions on Zenith-183 batteries and power supply Message-ID: Date: 28 Mar 91 01:21:18 GMT References: , <91085.134052RON@psuvm.psu.edu> Organization: Mathematics, Carnegie Mellon, Pittsburgh, PA Lines: 53 In-Reply-To: <91085.134052RON@psuvm.psu.edu> > Excerpts from netnews.comp.sys.zenith: 26-Mar-91 Re: Questions on > Zenith-183.. Ron McCarty@psuvm.psu.ed (1512) > I don't understand. My 183-92s batteries have been dead for almost a > year now but it hasn't prevented me from using the machine. I simply > removed the battery pack and use it exclusively on ac with the > powerpack. I have had no problems doing this. Thats strange. I wonder if we have different editions. My system has a diode network that prevents me from doing this. It looks like this: (This is a little simplified, there are other components, but this is the basic problem.) To low-power warning and auto-system shutoff. || || battery positive -----++-------Diode-- To rest of system power supply. Basically, this diode prevent me from doing just that -- running solely off AC. And because of the way the charger circuit works, the battery gets trashed really easily. My basic question is how to get around the problem without destroying the computer. Is it possible to hook up a external battery or DC power supply without connecting up the charger circuit AND without destroying/damaging the computer? I know that the zenith battery-pack contains several solid-state devices. Does anyone know what they do? I am assuming that they are either part of the charging circuit, or some sort of overload device. (I'm guessing.) Does anyone out there know how to do this (hook up a home-made external DC power system (ie either a battery or a DC power supply) to the computer's battery connections) SAFELY? Does anyone have any clues as to how this system works? Or should I just try it and hope/pray for the best? Thanks, -David Apfelbaum. ========================================================================= == David Apfelbaum Student (mostly Math/CS) at Carnegie Mellon. 5266 Beeler St. INTERNET, BITNET, etc: da0g+@andrew.cmu.edu Pittsburgh PA 15217 Alternate: da0g%andrew@CMCCVB (412) 683-7216 UUCP: ...!harvard!andrew.cmu.edu!da0g ========================================================================= == #include /* CMU is not responsible for my babblings. */ #include /* Beware of Hackers carrying screwdrivers. */ ========================================================================= ==