Active grounded thermocouple and method of operation
An active temperature measurement system includes at least one grounded thermocouple and a processor in communication with the at least one grounded thermocouple. The processor is configured to receive measurements from the at least one grounded thermocouple. The at least one grounded thermocouple is biased by an isolated voltage when the processor is receiving a measurement from the at least one grounded thermocouple.
1. A temperature measurement system comprising:
at least one grounded thermocouple operable to measure a temperature;
a processor in communication with the at least one grounded thermocouple, the processor being configured to receive the temperature measured from the at least one grounded thermocouple; and
a power supply coupled to the at least one grounded thermocouple and the processor, the power supply configured to receive a voltage input and generate an isolated voltage, wherein the at least one grounded thermocouple is selectively biased with the isolated voltage from the power supply during measurement of the temperature.
2. The system of claim 1 , further comprising an analog-to-digital converter in communication with the processor and the at least one grounded thermocouple, the analog-to-digital converter being configured to convert the temperature from the at least one grounded thermocouple to digital values and provide the digital values to the processor.
3. The system of claim 1 , wherein the at least one grounded thermocouple comprises:
a sheath having an open end and a closed distal end having a tip, the tip of the closed distal end defining a junction point; and
a signal wire extending from the open end to the junction point, wherein the signal wire and the sheath are made from dissimilar metals configured to produce an electric potential across the signal wire and the sheath, and the electric potential is indicative of a temperature at the junction point.
4. The system of claim 1 , further comprising a housing coupled to the least one grounded thermocouple, and the power supply is located within the housing.
5. The system of claim 4 , wherein the processor is located within the housing.
6. The system of claim 1 , wherein the power supply is configured to include an overvoltage circuit operable to control a voltage spike and a regulator operable to regulate the isolated voltage.
7. The system of claim 6 , wherein the overvoltage circuit includes a diode and a transistor.
8. The system of claim 1 , further comprising a network controller operable to output data to an external communication bus, the network controller in communication with the processor to output data from the processor.
9. The system of claim 8 , wherein the processor is configured to output the temperature measured from the at least one grounded thermocouple to the external communication bus via the network controller.
10. The system of claim 1 , further comprising:
a plurality of the grounded thermocouples, wherein the plurality of the grounded thermocouples are selectively biased with the isolated voltage one at a time, such that a grounded thermocouple being biased is providing the temperature;
a multiplexer in communication with the plurality of the grounded thermocouples and configured to receive the temperature taken from the grounded thermocouple being biased with the isolated voltage; and
an analog-to-digital converter in communication with the multiplexer and the processor, wherein the analog-to-digital converter is configured to convert the temperature received by the multiplexer to digital values and provide the digital values to the processor.
11. The system of claim 10 , further comprising a housing coupled to the plurality of the grounded thermocouple, wherein the power supply, the processor, the multiplexer, and the analog-to-digital converter are located within the housing.
12. The system of claim 10 , wherein the power supply is electrically coupled to and applies the isolated voltage to the multiplexer and the analog-to-digital converter.
13. The system of claim 1 , further comprising a plurality of the grounded thermocouples, wherein the plurality of the grounded thermocouples are selectively biased with the isolated voltage one at a time, such that a grounded thermocouple being biased is providing the temperature to the processor.
14. The system of claim 13 , further comprising a multiplexer in communication with the plurality of the grounded thermocouples and the processor, wherein the multiplexer is configured to provide the temperature taken from the grounded thermocouple being biased with the isolated voltage to the processor.
15. The system of claim 14 , wherein the multiplexer is configured to bias the grounded thermocouple that provides the temperature with the isolated voltage.
16. A temperature measurement system comprising:
a plurality of grounded thermocouples operable to measure a plurality of temperatures;
a processor in communication with the plurality of grounded thermocouples, the processor being configured to receive a temperature from the plurality of temperatures from a selected grounded thermocouple from among the plurality of grounded thermocouples; and
a power supply coupled to the plurality of grounded thermocouples and the processor, the power supply configured to receive a voltage input and generate an isolated voltage, wherein the plurality of grounded thermocouples are selectively biased with the isolated voltage one at a time, such that the selected grounded thermocouple providing the temperature is biased with the isolated voltage.
17. The system of claim 16 , wherein each of the plurality of grounded thermocouple comprises:
a sheath having an open end and a closed distal end having a tip, the tip of the closed distal end defining a junction point; and
a signal wire extending from the open end to the junction point, wherein the signal wire and the sheath are made from dissimilar metals configured to produce an electric potential across the signal wire and the sheath, and the electric potential is indicative of a temperature at the junction point.
18. The system of claim 16 , further comprising:
a multiplexer in communication with the plurality of grounded thermocouples and configured to receive the temperature taken from the selected grounded thermocouple being biased with the isolated voltage; and
an analog-to-digital converter in communication with the multiplexer and the processor, wherein the analog-to-digital converter is configured to convert the temperature received by the multiplexer to digital values and provide the digital values to the processor.
19. The system of claim 18 further comprising a housing coupled to the plurality of the grounded thermocouple, wherein the power supply, the processor, the multiplexer, and the analog-to-digital converter are located within the housing.
20. The system of claim 18 , wherein the power supply is electrically coupled to and applies the isolated voltage to the multiplexer and the analog-to-digital converter.