I have an MP3 player and want to know its standalone current consumption (when not plugged in to the USB port).
I used an inexpensive digital meter to measure the current consumption value but I had three obvious problems and maybe some less obvious ones. Is anyone able to get some more accurate figures than mine?
FWIW the player is based on a SigmaTel 35XX chip.
----- MY READINGS (ALKALINE OR NiMH AAA CELL)
Switch on (by holding one button down): 150-200 mA.
No activity, fully bright OLED [dimmed]: 50 mA [25 mA] Play voice recording, fully bright OLED [dimmed]: 75-85 mA [50 mA] Play music recording, fully bright OLED: 85-90 mA Record voice fully bright OLED [dimmed]: 95-100 mA [85-95 mA]
---- PROBLEMS AFFECTING MY READINGS
(problem 1) Unfortunately I saw the reading values "cycle" which probably was in line with the poor sampling rate of my meter.
(problem 2) Also I found that that the player would actually switch itself off as I changed functions which probably means my meter (in series with the AAA cell) was not as unnoticed by the player as it could have been.
(problem 3) The reading for microphone recording with dimmed display looks rather suspect even though it was taken repeatedly.