Page 326 - Solutions Manual to accompany Electric Machinery Fundamentals

SOLUTION
(a) The voltages v (t), v (t) and v (t) are shown below. Note that v (t) and v (t) look the same during
o
D
D
C
C
the rising portion of the cycle. After the PNPN Diode triggers, the voltage across the capacitor decays
R R
1 2
with time constant  = R + R 2 C, while the voltage across the diode drops immediately.
2
1

(b) When voltage is first applied to the circuit, the capacitor C charges with a time constant  = R C =
1
1
(500 k)(1.00 F) = 0.50 s. The equation for the voltage on the capacitor as a function of time during
the charging portion of the cycle is
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