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Mark Evans wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Tom Potts wrote: > >> Playing with my Viglen again and after yet another power outage yesterday I >> was wondering if anyone knows of a very low power (LCD?) monitor that would >> run of 12v - Black and white would do. >> The viglen runs of 12v, my router runs of 12v and if I can find a 12v monitor >> of low power than I can run the whole sheboodle of a car battery connected to >> a charger. >> > > There are quite a few LCD monitors with external PSUs. Some of these are > likely to be 12V or less. Though they might want a voltage regulator, > given that a "12V car battery" can actually be more like 14V. Especially > with a battery charger connected in parallel. > > You'd also want to avoid using a charger which is not designed to be > used in this way. If you are lucky you will just wind up with a broken > battery charger. If you are unlucky you will turn the battery into a > hydrogen gas and spark generator... > Car batteries are also not designed for deep cycle/long run operations. They are designed to deliver very high current for short periods of time. The sealed gel batteries are far more appropriate for battery powered equipment and can deliver far more energy over longer periods of time. Car batterys despite having a very high Ah rating will rapidly end up at a voltage that can cause sulphation of the cells and knacker the battery permanently. An optimum system would use not only a regulator but a switched mode system that can effeciently convert voltage up or down to the correct level of 12.0v. Regulators lower the extra voltage by dissipating current as heat, wasting your stored energy and with many types of battery there is still useful live below there nominal running voltage which can only be claimed with a switch mode/inverter topology for a regulator. RObin -- The Mailing List for the Devon & Cornwall LUG http://mailman.dclug.org.uk/listinfo/list FAQ: http://www.dcglug.org.uk/linux_adm/list-faq.html