TEMPERATURE MONITORED CABLE SYSTEM WITH TELEMETRY READ-OUT

摘要

1292475 Measuring temperature of power cables electrically ANACONDA WIRE & CABLE CO 26 June 1970 [7 July 1969] 31000/70 Heading G1N [Also in Division H1] In apparatus for measurement of the average temperature of a power cable 11 described in Specification No. 1157411 the bridge 28 unbalance voltage dependent upon the resistance of a temperature dependent pilot wire 10 is applied to a radio transmitter 28 for transmitting the measured value to a receiver at a ground station. The transmitter 28 includes an oscillator 29 the output frequency of which depends upon the bridge unbalance voltage and which is applied to the bi-phase modulator 30, Fig.3 (not shown) including a diode quad supplied with a carrier frequency from a crystal oscillator. The 180 degrees out of phase output signals from the modulator 30 are applied to antenna 32 mounted on a shielding housing carrying the measuring apparatus and which is integrally formed as an extension of a pothead, Figs. 1, 5 and 6 (not shown). Alternatively the transmitter 28 may be mounted on a separate shielded housing mounted on a corona ring extending about the pothead Fig. 4 (not shown). For monitoring a single cable conductor a multiconductor pilot wire may be incorporated in a four segment cable, Fig. 7 (not shown) the pilot conductors being connected to segmented conductors at separate points along the cable. Each pilot wire may be connected to a different Wheatstone bridge and transmitter circuit, Fig. 8 (not shown) the outputs of which are connected to a three channel transmitter so that the output of the receiver indicates an average temperature.