CPC G01K 7/226 (2013.01) [G01K 7/16 (2013.01); G01K 7/22 (2013.01); G01K 7/34 (2013.01); H03B 5/04 (2013.01); H03B 5/30 (2013.01); H03H 9/02244 (2013.01); H03L 1/02 (2013.01); G01K 7/12 (2013.01); G01K 7/186 (2013.01); G01K 2219/00 (2013.01)] | 21 Claims |
1. A device to measure a value of an environmental parameter, the device comprising:
a first circuit structure having an electrical circuit parameter that varies dependent on variation in the environmental parameter to be measured;
a second circuit structure comprising at least one capacitor and a switch to cause the at least one capacitor be switched at a frequency that causes the at least one capacitor to exhibit an effective resistance that varies according to variation of the frequency, the second circuit structure characterized by an electrical circuit parameter that varies dependent on the effective resistance;
circuitry to generate a control signal dependent on a relationship between the electrical circuit parameter of the first circuit structure and the electrical circuit parameter to the second circuit structure, in a manner that adjusts the effective resistance so as to drive the relationship toward a predetermined state; and
circuitry to produce an output signal, representing measurement of the value, dependent on the control signal.
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