>I couldn't find any state of personal wearable use.. but I imagine it's >less then 10,000 users in the US.. or 0.0001%. A ballpark figure for this number would be very interesting, as would breakdowns by manufacturer (Xybernaut, ...?) and by application (medical, auto and aero service, military, space, ...). Can we say for sure that there are more than 1,000, or even 100, users out there of what this group would regard as a wearable computer? >Let's be honest.. most wearables are built with desktop technology >scaled down to at minimum pc/104 scale.. PC/104 was the scale of several years ago. One can make a wearable a lot smaller than pc/104 these days, e.g. if you don't insist on a blazing fast Pentium then the Matchbox PC (http://wearables.stanford.edu/) including 340 MB hard drive is 2.8" x 1.8" x .9". >but with such vast power requirements for hard drives, fast processors, >and displays that half your weight is batteries. About right. The Matchbox PC including 340 MB drive weighs 3 oz. and the full-function port expander adds another 1.8 oz (less for an expander that omits parallel and floppy ports). It runs for 5.2 hours on a pair of Sony NP-FM50 batteries each weighing 2.2 oz. The volume of the two batteries is a few percent more than that of the PC itself not counting the port expander. A pair of the considerably bigger Sony NP-FM950 batteries runs it for at least 17 hours, I haven't yet flattened these. All this via National's 2675-5.0 switching regulator (we use National's little $8 evaluation board, which we just started using the past few days, we were using 7805's at ISWC), which will take any DC input from 8 to 40 volts and runs at a flat 90% efficiency (the 12 volt version is 94%, 3.3V is 86%). At idle the Matchbox draws 200 mA from an auto cigarette lighter with the engine off, dropping to 180 mA when you start the engine since the voltage jumps from 12.5 volts to 14 volts. At full bore including heavy disk use the current (at 12.5V) goes up to 500 mA (6.2 watts). For comparion an Olympus 600 consumes 10 watts for the first 4 seconds of writing out a photo dropping to 5.5 watts for the remaining 5 seconds (due to the flash finishing recharging after 4 seconds), and idles thereafter at 2.5 watts until it turns off, exactly the same as the Matchbox PC idling. >A cellular phone weighs an order of magnitude less and doesn't need as >much power. Of course this is mostly because it doesn't have a high >powered processor capable of driving a desktop OS, or have enough memory >to store anything more then a few addresses and phone numbers. A cellphone today weighs 3-6 oz (my StarTAC with the slim battery is 3 oz and with the bigger auxiliary battery is 5 oz). The Matchbox PC is 9 oz including port expander and two NP-FM50 batteries, making it nowhere near an order of magnitude bigger, more like a factor of two depending on exactly what you compare with what. That factor of two buys you your choice of RedHat 6.0 Linux or Windows 98 which obviously couldn't fit in any of today's cellphones, but maybe in the cellphones of 2002. Vaughan -- Subcription/unsubscription/info requests: send e-mail with subject of "subscribe", "unsubscribe", or "info" toWear-Hard Mailing List Archive (searchable): http://wearables.blu.org
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