Ok Igor, you finally motivated me to do some measurements :-) All measurements were done with a .1 ohm resistor (measured as .0924 ohms using the 4-wire method) and a HP 3456A 6.5 digit voltmeter. The meter was set to the slowest (most accurate) sampling rate, performing the calculations on-the-fly for the Ohm's law derived current. I did _not_ measure battery voltage, so wattage calculations are not possible. This shouldn't be a big deal as the current will give a good indication of what the device is doing at the time. I've attached a CSV file of the spreadsheet for results. I tried to hit most of the use cases people might be interested in, and everything is pretty impressive except for leaving MP3 files paused in the media player, which consumes over 10 times the normal current while sleeping.
Larry On 3/29/06, Igor Stoppa <[EMAIL PROTECTED]> wrote: > Hi, > > On Tue, 2006-03-21 at 11:31 -0500, ext Larry Battraw wrote: > > I would advocate building a dummy battery out of a piece of > > wood/plastic with a small piece of copper clad board (split into three > > pads) to act as the contacts of the battery. You can then run wires > > from those to the real battery, passing it through whatever > > resistor/sensing equipment you want. As soon as you try measuring > > what goes into the DC jack you're then including whatever losses > > incurred by the DC-DC conversion from 5V to whatever used internally, > > as well as issues around having it potentially trying to charge the > > battery at the same time you're measuring. That, and Igor as much as > > said that things could behave differently based on whether it detects > > wall/DC power vs. battery power alone. Honestly, at this point you > > probably could have built a couple rigs for measuring power from the > > battery in all the time that has been spent discussing it. :-) > > > > Larry > > > > On 3/21/06, Frantisek Dufka <[EMAIL PROTECTED]> wrote: > > > > > Well I was not thinking about measuring at the mains plug. I was > > > thinking about measuring at the n770 side (5V?) because it is a bit > > > easier then opening the device and messing with battery pins. > > > > > > Frantisek > > _______________________________________________ > > maemo-developers mailing list > > maemo-developers@maemo.org > > https://maemo.org/mailman/listinfo/maemo-developers > > did anybody produce anything? > > I was hoping that the discussion would bring some interest to the > fabulous world of power management also amongst other developers ... > > -- > Cheers, > Igor > > Igor Stoppa (Nokia M - OSSO / Tampere) >
,,"Nokia 770 Current Measurements",, ,,,, "Current in mA",,"Activity",,"Notes" 8,,"Sleep/backlight off",,"Pulses to 12 mA every few seconds" 93,,"Lowest brightness of backlight",, 110,,"3 bars brightness",, 128,,"5 bars",, 179,,"7 bars",, 202,,"Max brightness",,"All figures with no application running" ,,,, 430,,"Scanning for WAPs",,"All wireless figures @ min brightness" 390,,"At pick AP window",, 100,,"Idle",, 80,,"Idle, ½ bright",, 530,,"Loading Opera",, 400,,"Rendering page (load from net complete)",, 570,,"Loading/rendering page",, 388,,"At control panel window",, 100,,"Idle after 10 seconds from closing control panel",, ,,,, 230,,"64Kbps MP3 playing at full volume (min bright)",, 190,,"Volume at minimum",, 178,,"Paused",, 107,,"Playing, backlight off",, 80,,"Paused, backlight off (!!!)",, ,,,,"Same figures for 128Kbps MP3"
_______________________________________________ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
