The power supply you link to is very similiar to the one in the Cubid cases. No one has been able to get much information whether it can take anything other than exactly 12v, but the link you give says that it takes ONLY ONLY ONLY 12volts. This is a problem: Car voltage is 12v only sometimes, usually it is 13.8v, when you start the car it can go to 6v, and when you are running without any accessories you can go as high as 14v or so.. and there are spikes of course.. So you could get a Zener diode and just burn off the excess voltage in the car as heat, but the system would reboot when you start the car and the voltage goes below 6v.. unless you get a car audio capacitor to compensate.. which may or may not work in this situation.. running off of batteries, you need a good regulator.. usually regulators take input that is a couple volts higher than output.. so you would need 14v or higher input to regulate to 12v... building one is not very fun as you need lots of voltages instead of just 5v on an embedded board.. if you want to go the route you have now, maybe use the following which will work in a car or batteries.. I just am not positive about its efficiency.. http://home.attbi.com/~zootjeff/ otherwise you have reasonable plan.. embedded boards may give more power but everything has advantages and disadvantes, if this is what you know and can get and afford then sounds good. Bryan On Fri, 14 Feb 2003, ben wrote: > I've found the EPIA 5000 motherboard, with 533Mhz Eden CPU to be suitable ( > http://www.viavpsd.com/product/epia_mini_itx_spec.jsp?motherboardId=2 ). > It's quite small, and has great power consumption for an x86 system. There's > also some great PSUs available, at reasonable prices (like this one > http://store.ituner.com/ituner/miniitxpower.html ), that I can use to power > the system from an AC adapter, a battery, or an automobile cigarette lighter. > For the battery, I'll be using 2 sets of 10 series wired NiMH "C" cells > (1.2v, 4000mAh), in a parallel circuit, for a total output of 12v & 8Ah. > Given the 14W consumption that's been mentioned on this list, I should be > able to power the unit for almost 7 hours. Obviously, it will be a lot less > if I'm actually doing anything with it, as various perpherals and drives will > be consuming significant amounts of power, but I feel confident that this > will give me enough power to do things like listening to & composing email > through headphones & twiddler with emacspeak, for a few hours, or so. > > I should be able to add a laptop hard drive, slimline CD or DVD drive, and > IDE CF drive. I'll probably attempt to use only the CF drive, when running > off of battery power. > > Any thoughts or advice? The only challenging part of this projects, that I > can see, are getting the battery power right, and heat (I'll probably need to > put at least one fan in, although I'd like to avoid it, if at all possible). > > -ben -- Subscription/unsubscription/info requests: send e-mail with subject of "subscribe", "unsubscribe", or "info" toWear-Hard Mailing List Archive (searchable): http://wearables.blu.org Please, *PLEASE* don't subscribe through a forward/expander/false domain
From Wear-Hard Mailing list Archive (WH)
Maintained by R. Paul McCarty
Archive created with babymail