Pulse Current or PC is Direct Current made “non-continuous” by chopping it up into on/off or -ve/+ve intervals. PC power can transmit over a pair of copper conductors like DC power. Pulse Current is unique because the current continuously drops to zero or crosses zero, and power switches off quickly if a fault is detected. Class 4 Power Systems, such as Pulse Power, transmit power in a PC form and have protective circuits that can detect a fault and turn the power off almost instantly to prevent hazards related to electrical shock and fire risk. Class 4 system vendors that use PC for power delivery will control the pulse shape, magnitude, and duration depending on the safety mechanisms they use for fault detection.
The Pulse Power system uses a PC waveform of +/- 180VDC pulses that are three milliseconds (ms) long, 2 ms of which are used to supply power, and 1 ms to check for faults (Safety Check). The Diagrams below show a PC waveform in normal and fault conditions.
