Volts are the same, but AMPs vary. Touchstone has high mA requirements, which is why it won't work with USB, and why certian wall worts are needed. The power requirements for the Touchstone are 1000mA. USB = something more like 500mA. Many car chargers are also just 500mA. Sam
________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Don Pomplun Sent: Monday, August 17, 2009 5:21 PM To: [email protected] Subject: [Treo] Re: Car or Desktop Charger for Touchstone Back --- In [email protected] <mailto:treo%40yahoogroups.com> , "Leland Cox" <lcox...@...> wrote: > > I am surprised someone hasn't come up with a Car or Desktop Charger for use with the Touchstone Back. This isn't rocket science! The circuit in the touchstone has to be a simple circuit that would be easy to duplicate. > > This would give us access to USB free charging stands and car chargers that use the Touchstone Back. I really got tired of plugging the cable in every night before I got the Touchstone. I thought the same, and planned to make Touchstone stands once I got my first official one, which just showed up. Before I installed the TS back on my Pre I measured the output on the little contacts. It shows about 5.5 volts DC. And the USB norm is about the same. So the *puck* must convert the DC into a (probably) high frequency AC voltage, good for about half a watt. I see you can get the stand alone for about $37 (I think w/o the wall wart & cable). Making your own should be cheap, but the homebrew form factor might be a little ugly. I'll probably just complain for a while then buy one for the car ;=) [Non-text portions of this message have been removed]
