I have a circuit of 6 solenoids connected to Darlington Array (http://www.ti.com/lit/ds/symlink/uln2803a.pdf) and driven by 18V (2x9V batteries) as can be seen below:
From what I understand, each load should draw 200mA (18V/88Ohm) and when all of them are switched on at the same time, the total draw should be 1.2A. They are all in the active state for a brief moment (20ms).
I wanted to confirm my calculations by measuring the total current draw with a multimeter connecting it in series with the current source.
The measurements showed a maximum of 47mA draw instead of 1.2A.
What could be the reason why the actual measurement does not match the theoretical?