Abstract: A system for monitoring at least one parameter of either an energized electrical power line conductor or at least one parameter adjacent to the power line conductor, on a real-time basis and transmitting signals indicative of the parameter to a remote location where the power line conductor itself is the transmission medium for transmitting the signals to the remote location. The transmitter is powered by either the electric or the electromagnetic field of the energized power line conductor and the transmitter receives induced energy from the conductor via a plurality of turns of wire wound around a mandrel, with the plurality of turns of wire formed as the secondary winding of a transformer, and with the mandrel being at the same electrical potential as the conductor.

Abstract: Circuit for generating from a pair of pulse trains produced in phase quadrature both an indication of the direction of print head motion and the production of timing signals from the leading and trailing edges of the pulses of only one of the two pulse trains. A pair of transducers is used to sense a timing disk rotating in synchronism with the movement of a carrier for a plurality of print elements moving along a print line which transducers are generating respective output pulse trains which are in phase quadrature relation to the other. The circuit provides timing signals for controlling the energization of the print elements at print positions along the print line and retains the same polarity for printing in either direction.

Abstract: Apparatus for directly monitoring the conductor temperature or other parameters of an energized electric power line conductor, or of the medium adjacent the conductor, on a real time basis, and transmitting a signal indicative of that parameter to a remote location such as to facilitate data processing by computer. The apparatus is powered by the electric or electromagnetic field of the electric power line conductor.Various embodiments are described for sensing the temperature or other parameter being monitored. Furthermore two techniques are described for transmitting the signal to a remote location. The first such technique is the use of air as the transmission medium and the second technique uses the power line conductor itself as the transmission medium.