[volt-nuts] Cheap Oscilloscope measurement of small current?

Andreas Jahn Andreas_-_Jahn at t-online.de
Fri Nov 5 08:29:33 UTC 2010

> Hello, all. I'm working (very slowly, but working) on some designs that
> will be battery (and possibly solar) powered sensors with a wireless
> data backhaul (likely 433 or 915MHz).
> As part of my never ending quest for more tools, I'm starting to educate
> myself on what I may need to get measurements on current usage over time
> for these devices. I want to be able to quantify power usage while it is
> asleep, sensing, sending data, etc..."does changing this code shorten
> the radio on time?"
> I'm sure Agilent would be happy to sell me a fancy oscilloscope current
> probe for more than my condo cost, but I'm looking for something more
> cost effective.
> Suggestions from the hive mind?
> Thanks.
> -Pete

Hello Pete,

for comparative measurements you could supply the cirquit from 
a (foil) capacitor which is recharged by a relative high-ohmic resistor
or current source. From the voltage dips on the capacitor you could
estimate the (integrated) energy of the wakeup-phases.

with best regards


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