# US 10,120,006 B2 · Method of operating LC sensors, corresponding system and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,120,006 B2 - Document ID: US10120006B2 - Status: Granted - Kind: B2 - Application number: 15/070,509 - Filed: 2016-03-15 - Published: 2017-03-16 - Granted: 2018-11-06 - Earliest claimed: 2015-09-10 - Assignees: STMicroelectronics S.r.l. - Applicants: Stmicroelectronics S.R.L. - Inventors: Riccardo Condorelli; Daniele Mangano - Web page: https://patentgrep.com/patent/US10120006B2 ## CPC - G01R 27/26: Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants {; Measuring impedance or related variables} - G01D 5/20: by varying inductance, e.g. by a movable armature - H03K 17/9537: {in a resonant circuit} - H03K 17/954: {controlled by an oscillatory signal} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract In one embodiment, an inductive/LC sensor device includes: an energy storage device for accumulating excitation energy, an LC sensor configured to oscillate using energy accumulated in the energy storage device and transferred to the LC sensor, an energy detector for detecting the energy accumulated in the energy storage device reaching a charge threshold, and at least one switch coupled with the energy detector for terminating accumulating excitation energy in the energy storage device when the charge threshold is detected having been reached by the energy detector. ## Claims ### Claim 1 A method comprising: accumulating excitation energy for an inductive-capacitive (LC) sensor, oscillating the LC sensor using the excitation energy accumulated, detecting the excitation energy accumulated reaching a charge threshold, and terminating accumulating the excitation energy for the LC sensor in response to detecting the excitation energy accumulated reaching the charge threshold, wherein the accumulating includes: short-circuiting a reference capacitor that is coupled in series to the LC sensor, starting accumulating excitation energy for the sensor by coupling the LC sensor to an energy source with the reference capacitor short-circuited, and removing the short-circuit across the reference capacitor while maintaining the LC sensor coupled to the energy source. ### Claim 2 (depends on 1) The method of claim 1, wherein: the short-circuiting includes closing a switch that is connected in parallel with the reference capacitor. ### Claim 3 (depends on 1) The method of claim 1, wherein detecting the excitation energy accumulated reaching the charge threshold includes detecting a voltage across the reference capacitor reaching a voltage threshold. ### Claim 4 (depends on 1) The method of claim 1, including a reset step that shorts the LC sensor to a ground terminal. ### Claim 5 An LC sensor device, comprising: an energy storage device configured to accumulate excitation energy, an LC sensor coupled to the energy storage device and configured to oscillate when energized by the excitation energy in the energy storage device, an energy detector configured to detect the excitation energy in the energy storage device reaching a charge threshold, and at least one switch coupled with the energy detector and configured to terminate accumulating the excitation energy in the energy storage device in response to energy detector detecting that the charge threshold has been reached by the excitation energy in the energy storage device, wherein: the energy storage device includes a reference capacitor coupled in series to the LC sensor; the at least one switch includes a first switch and a second switch, the first switch being configured to selectively couple the LC sensor to an energy source and the second switch being configured to selectively short-circuit the reference capacitor, and the energy detector is configured to close the first switch to electrically couple the LC sensor to the energy source and open the second switch to remove the short-circuit across the reference capacitor while the LC sensor is electrically coupled to the energy source by the first switch. ### Claim 6 (depends on 5) The LC sensor device of claim 5, wherein: the second switch is connected in parallel with the reference capacitor. ### Claim 7 (depends on 5) The LC sensor device of claim 5, wherein: the energy detector is configured to detect the energy accumulated reaching the charge threshold by detecting a voltage across the reference capacitor reaching a voltage threshold. ### Claim 8 (depends on 5) The LC sensor device of claim 5, wherein the at least one switch is configured to selectively short circuit the LC sensor to a ground terminal. ### Claim 9 (depends on 5) The LC sensor device of claim 5, wherein at least one of the energy detector and the at least one switch is implemented by a controller unit. ### Claim 10 A fluid flow sensing device, comprising: a sense structure configured to be moved by a fluid flow; and an LC sensor device coupled to the sense structure and configured to sense movement of the sense structure, the LC sensor including: an energy storage device configured to accumulate excitation energy, an LC sensor coupled to the energy storage device and configured to oscillate when energized by the excitation energy in the energy storage device, an energy detector configured to detect the excitation energy in the energy storage device reaching a charge threshold, and at least one switch coupled with the energy detector and configured to terminate accumulating the excitation energy in the energy storage device in response to the energy detector detecting that the charge threshold has been reached by the excitation energy in the energy storage device, wherein: the energy storage device includes a reference capacitor coupled in series to the LC sensor; the at least one switch includes a first switch and a second switch, the first switch being configured to selectively couple the LC sensor to an energy source and the second switch being configured to selectively short-circuit the reference capacitor, and the energy detector is configured close the first switch to electrically couple the LC sensor to the energy source and open the second switch to remove the short-circuit across the reference capacitor while the LC sensor is electrically coupled to the energy source by the first switch. ### Claim 11 (depends on 10) The fluid flow sensing device of claim 10, wherein: the second switch is connected in parallel with the a reference capacitor. ### Claim 12 (depends on 10) The fluid flow sensing device of claim 10, wherein: the energy detector is configured to detect the energy accumulated reaching the charge threshold by detecting a voltage across the reference capacitor reaching a voltage threshold. ### Claim 13 (depends on 10) The fluid flow sensing device of claim 10, wherein at least one of the energy detector and the at least one switch is implemented by a controller unit.