Dual slope DVMS discharging concept

Thread Starter

arwa hawwa

Joined Jul 13, 2014
in dual slope I am stuck in understanding one thing
why the capacitor start discharging when the switch switches from the voltage of X to the ref voltages !
what is the reason that makes the capacitor discharge ?


Joined Mar 14, 2008
Typically the capacitor charges with a current proportional to the input voltage for a fixed time and then is discharged by a constant-current source controlled by a reference voltage for the same fixed time.
From that you can calculate the input voltage with reasonably good accuracy, and the tolerance of the capacitor value has no effect on that accuracy.