# US 12,007,444 B2 · Spark discharge detection device having waveform extension circuit and spark discharge detection method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,007,444 B2 - Document ID: US12007444B2 - Status: Granted - Kind: B2 - Application number: 17/931,171 - Filed: 2022-09-12 - Published: 2023-09-21 - Granted: 2024-06-11 - Earliest claimed: 2022-03-18 - Assignees: Kabushiki Kaisha Toshiba - Applicants: Kabushiki Kaisha Toshiba - Inventors: Yasuhiro Kanekiyo - Web page: https://patentgrep.com/patent/US12007444B2 ## CPC - G01R 31/343: {in operation} - G01R 19/165: Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A spark discharge detection device includes a discharge detector, a waveform extension circuit, and determination circuit. The discharge detector includes a metal electrode that detects discharge between an electrode and a sliding body that is in contact with and sliding surface of the electrode. The waveform extension circuit configured to extend a discharge waveform output from the discharge detector in a time direction. The determination circuit configured to determine that discharge has occurred in the sliding body when a signal value exceeds a first threshold and a time during which the signal value exceeds the first threshold is held for a time longer than a first time for the output of the waveform extension circuit. ## Claims ### Claim 1 A spark discharge detection device comprising: a discharge detector detecting spark discharge between an electrode and a sliding body that is in contact with a sliding surface of the electrode; a waveform extension circuit configured to extend a discharge waveform output from the discharge detector in a time direction and output the extended discharge waveform; and a determination circuit configured to determine that discharge has occurred in the sliding body when a value of the extended discharge waveform exceeds a first threshold and a time during which the value exceeds the first threshold is held for a time longer than a first time for the output of the waveform extension circuit. ### Claim 2 (depends on 1) The spark discharge detection device according to claim 1, further comprising: a voltmeter that is coupled to the waveform extension circuit and configured to measure a voltage of the output waveform, wherein the determination circuit determines that discharge has occurred based on the voltage output from the voltmeter. ### Claim 3 (depends on 2) The spark discharge detection device according to claim 2, wherein the waveform extension circuit is an integration circuit that has a predetermined voltage holding time constant, and the voltmeter detects and holds the discharge waveform for a sampling time of ½ or less of the predetermined voltage holding time constant. ### Claim 4 (depends on 3) The spark discharge detection device according to claim 3, further comprising: a clear circuit configured to return a voltage signal held at the predetermined voltage holding time constant to an initial value after a second time elapses after the voltage signal detected by the voltmeter exceeds the first threshold, between the waveform extension circuit and the voltmeter. ### Claim 5 (depends on 2) The spark discharge detection device according to claim 2, further comprising: a filter that is coupled between the discharge detector and the waveform extension circuit and configured to selectively transmit a portion of a signal having a component larger than a second threshold with respect to a waveform of a discharge signal captured by the discharge detector, wherein the waveform extension circuit processes an output of the discharge detector via the filter. ### Claim 6 (depends on 2) The spark discharge detection device according to claim 2, further comprising: a filter circuit configured to limit a discharge signal captured by the discharge detector to an electric signal having a predetermined amplitude, at a preceding stage of the waveform extension circuit or a preceding stage of the voltmeter. ### Claim 7 (depends on 2) The spark discharge detection device according to claim 2, further comprising: a filter circuit that is coupled to the discharge detector and configured to selectively extract a signal of a predetermined frequency band with respect to a discharge signal captured by the discharge detector. ### Claim 8 (depends on 2) The spark discharge detection device according to claim 2, wherein the discharge detector has a pair of balanced metal electrodes as the metal electrodes. ### Claim 9 (depends on 2) The spark discharge detection device according to claim 2, further comprising: a plurality of the discharge detectors, wherein the device, by comparing result of signal processing based on signals output from the plurality of discharge detectors, detects that discharge has occurred. ### Claim 10 (depends on 9) The spark discharge detection device according to claim 9, wherein at least one of the plurality of discharge detectors has a pair of balanced metal electrodes, and balanced outputs from the discharge detectors having the pair of balanced metal electrodes to respective circuits by a balanced line. ### Claim 11 (depends on 2) The spark discharge detection device according to claim 2, wherein the discharge detector divides an output of the discharge detector into a plurality of branches, and compares signal processing results in the respective branches to detect that discharge has occurred. ### Claim 12 (depends on 2) The spark discharge detection device according to claim 2, further comprising: an insulating portion of which a coupling end is physically insulated from an internal electric circuit of the waveform extension circuit on an input side of the waveform extension circuit, and that transmits an electric signal. ### Claim 13 A spark discharge detection method comprising: detecting, by a discharge detector, spark discharge between an electrode and a sliding body that is in contact with a sliding surface of the electrode; extending, by a waveform extension circuit, a discharge waveform output from the discharge detector in a time direction and output the extended discharge waveform; and determining, by a determination circuit, that discharge has occurred in the sliding body when a value of the extended discharge waveform exceeds a first threshold and a time during which the value exceeds the first threshold is held for a time longer than a first time for an output of the waveform extension circuit.