Dual slope DVMS discharging concept

Discussion in 'General Electronics Chat' started by arwa hawwa, Nov 19, 2015.

  1. arwa hawwa

    Thread Starter New Member

    Jul 13, 2014
    6
    0
    hello
    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 ?
     
  2. crutschow

    Expert

    Mar 14, 2008
    13,053
    3,244
    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.
     
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