Figure 27. Effect of medium RL time constant
(2) If the same square wave is applied to an RL circuit having
a shorttime constant in respect to its duration time (Figure 28A),
ER (Figure 28E) rises quickly to a value equal to E when the pulse is
applied, and falls rapidly to zero when the pulse decays to zero. On
the other hand, the voltage waveform across the inductor (Figure 28D)
assumes the form of alternate positive and negative triggers having
peak values equal to E and E.