Circuit for monitoring temperature of high-voltage equipment
An improved circuit for measuring temperature in a region at high electric potential and generating a read-out of the same in a region at lower potential is described. The circuit is specially designed to combine high sensitivity, stability, and accuracy. A major portion of the circuit situated in the high-potential region can take the form of an integrated circuit. The preferred form of the circuit includes an input section which is situated in the high-potential region and comprises a temperature-compensated thermocouple circuit for sensing temperature, an oscillator circuit for generating a train of ramp voltages whose rise time varies inversely with the thermocouple output, a comparator and switching circuit for converting the oscillator output to pulses whose frequency is proportional to the thermocouple output, and a light-emitting diode which is energized by these pulses. An optical coupling transmits the light pulses generated by the diode to an output section of the circuit, situated in a region at ground. The output section comprises means for converting the transmitted pulses to electrical pulses of corresponding frequency, means for amplifying the electrical pulses, and means for displaying the frequency of the same. The preferred embodiment of the overall circuit is designed so that the frequency of the output signal in hertz and tenths of hertz is equal to the sensed temperature in degrees and tenths of degrees.
- Assignee:
- Energy Research and Development Administration
- Patent Number(s):
- US 3978729
- OSTI ID:
- 7323284
- Resource Relation:
- Patent File Date: Filed date 9 Dec 1975; Other Information: PAT-APPL-639,134
- Country of Publication:
- United States
- Language:
- English
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