Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!bloom-beacon!hermes!jpexg
From: jpexg@hermes.ai.mit.edu (John Purbrick)
Newsgroups: sci.electronics
Subject: Re: SRAM Battery backup
Summary: How about mega-capacitors?
Message-ID: <3363@hermes.ai.mit.edu>
Date: 16 May 89 03:02:26 GMT
References: <657@serene.UUCP> <1989May15.043845.25572@utzoo.uucp>
Organization: MIT AI Lab, Cambridge, MA
Lines: 7


Recently I've seen huge (electrically, not physically) capacitors in the 
Digi-Key catalog. A whole farad! They have fairly high internal resistance
(~50 ohm) but to keep a trickle going into a memory chip, which is what they're
designed for, they should be OK. Whether something like this would do the job
depends on how long the system has to be kept alive without being plugged in, 
which would recharge the cap of course.