Thread: (Nokia 770) + (USB host power hack) + (USB keyboard) != working
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lbattraw is offline lbattraw
2006-04-09 , 02:11
Posts: 209 | Thanked: 8 times | Joined on Nov 2005 @ Fishers, Indiana
#17
Originally Posted by ThaddeusMorgan
The Nokia AC-4E adaptor doesn't supply a consistent voltage when plugged into both the Nokia and my kludged on 5V regulator
(snip)
My question now is, what is the maximum input voltage from the charging adaptor the Nokia 770 can handle? Note that almost all AC->DC converters actually output a higher voltage than indicated on the packaging. Thanks. -TM-
Please don't try connecting the 770 to a 5V (Or another voltage) supply directly. The 770 depends on having its supply current-limited at somewhere around 500 mA. This is my experience anyway, and if you fry your tablet you get to keep the charred remains :-) The third-party charger I bought puts out 6V current-limited at 500 mA and seems to work fine. It never goes above 6V and utilizes a switchmode circuit to allow you to plug it into 120VAC or a cigarette lighter receptacle.

Larry