Verifying the diode-capacitor circuit voltage decay

The voltage on a capacitor discharging through a forward biased diode is calculated from basic equations and is found to be in good agreement with experimental measurements. In contrast to the exponential time decay for a RC circuit, the nonlinear characteristics of the diode result in a nonexponential decay for the diode-capacitor circuit. For a silicon diode the decay is predominantly a logarithmic function of time. (C) 2003 American Association of Physics Teachers.