Consider a section of transmission line shorted at one end, connected to a voltage source of zero internal impedance at the other. A large current will quickly develop as waves of current and voltage propagate back and forth along the line.
Figure 1. Transmission Line Animator configuration for a shorted transmission line. A 50 ohm line is terminated with zero ohm resistor, and driven by a 1 volt battery of zero internal impedance. The line is 12 cm in length.
Figure 2. Initial waves of current (20 mA) and voltage (1 V) are launched on the line to the right, shown at .173nS.
Figure 3. Counter propagating waves are reflected at the short. The reflected current wave adds to the initial current, the reflected voltage wave cancels the initial voltage, as required by the terminating short. At .597 nS on the left is 20 mA and 1 V on the right are 40 ma and 0 V.
Figure 4. Stroboscopic view of animation at .18 nS intervals. Voltage on line alternates between 0 V and 1 V. Current increases in 20 mA increments.
Figure 5. Evolution of conditions on the line at a probe. Voltage on line alternates between 0 V and 1 V. Current increases in 20 mA steps. Markers indicate 40 mA and 60 mA.