HP-16C current consumption

[Sadsilence]

(07-13-2017 05:01 PM)Dave Frederickson Wrote:  How are you measuring the current? I understand that DMM's have a burden resistor that affects low current measurements. Consequently, there are devices that overcome that limitation. For example:
https://www.eevblog.com/projects/ucurrent/

Honestly I did not measure current at all. It is simply a matter of calculation. A battery with a capacity of 40 mAh (that is what I measured) runs out in 68h:20min:

40 mAh / 68,33 h = 0,585 mA = 585uA

Of course there may be an error of a few percent, because battery capacity is taken from previous runs. Nevertheless exact result is surely between 550uA and 600uA which is more than impressive.

Measuring current of a running processor with a DMM is difficult cause current consumption changes within ms or us (nowaday within ns) and may irritate DMM's low path filter.