time T1 (time one, when the capacitor reaches full charge or

discharge potential will be used. Note that switches S1 and S2

move at the same time and can never be both closed at the same

time.

When switch S1 of the circuit in figure 34 is closed at to, the

source voltage (Es) is instantly felt across the entire circuit.

Graph A, figure 34, shows an instantaneous rise at time to from

zero to source voltage (Es = 6 volts). The total voltage can he

measured across the circuit between points 1 and 2. Now look at

figure 34, graph B, which represents the charging current in the

capacitor (ic). At time to, charging current is MAXIMUM. As time

elapses forward time t1, there is a continuous decrease in

current flowing into the capacitor. The decreasing flow is

caused by the voltage buildup across the capacitor. At time t1

current flowing in the capacitor stops. At this time, the

capacitor has reached full charge and has stored maximum energy

in its electrostatic field. Figure 34, graph C, represents the

voltage drop (er) across the resistor (R). The value of er is

determined by the amount of current flowing

FIGURE 34. CHARGE OF AN RC SERIES CIRCUIT.