Patent ID: 8649444

Claim:
In a transponder for use in a TWACS for transmitting inbound communications from a location where the transponder is located to another location over a utility's power transmission lines, the inbound communications being composed of positive and negative pulses imposed on an AC waveform and the transponder including an inductor through which the pulses are propagated, apparatus for controlling current flow through the inductor comprising: an electrical circuit to which the inductor is connected, the circuit comprising switch means controlling the direction of current flow through the inductor for each pulse propagated therethrough; and, monitoring means monitoring the direction of current flow through the inductor with the occurrence of each pulse, the monitoring means controlling the switch means to route current flow through the inductor in the opposite direction from that of current flow for the previous pulse regardless of whether the previous pulse and the subsequent pulse are of the same or a different polarity, whereby the magnetization of a core of the inductor does not have to be overcome by energy in the subsequent pulse but is maintained at a level that allows the resulting amplitude, whether positive or negative, of all the pulses imposed on the AC waveform to be substantially constant.