Hi I am trying to use the PPK 2 to measure current draw from 9V battery for a DUT. I am able to use the PPK2 in source mode. However I will like to set it up in Ampere meter mode so I can account for the discharge characteristics of the battery over time. There is a similar case from more than 2 years ago when one response suggested use of a Buck converter or LDO between the 9V battery and the PPK 2 which would provide the necessary 5V required by the PPk2 and then account for the power consumed by the Buck Converter. However that response was not marked as answering the question and I am not sure if the case was closed. How would you account for the power/current consumed by the regulator?
I also did some initial tests using the PPK 2 in source mode to try to understand how different setups would potentially affect current draw in my circuit. Its a simple circuit for driving an LED
Below is a snap shot of three different configurations I tested.
In each of them I got a different average current reading from PPK 2 as shown below.
I was expecting Test circuit 1 to draw the least and test circuit 3 to draw the most accounting for losses in the diodes used for reverse polarity protection but its rather the opposite and I am not sure why. Any explanation will be be helpful
Thanks
