# US 11,451,050 B2 · Chromatograph apparatus and load switch circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,451,050 B2 - Document ID: US11451050B2 - Status: Granted - Kind: B2 - Application number: 16/725,322 - Filed: 2019-12-23 - Published: 2020-07-16 - Granted: 2022-09-20 - Earliest claimed: 2019-01-16 - Assignees: Shimadzu Corporation - Applicants: Shimadzu Corporation - Inventors: Yugo Ishihara - Web page: https://patentgrep.com/patent/US11451050B2 ## CPC - H02H 9/001: {limiting speed of change of electric quantities, e.g. soft switching on or off (progressive control of electronic switches for eliminating interferences H03K17/16)} - G01N 30/88: Integrated analysis systems specially adapted therefor, not covered by a single one of the groups G01N30/04 - G01N30/86 - H03K 17/16: Modifications for eliminating interference voltages or currents - G01N 30/02: Column chromatography - H05B 41/36: Controlling - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - 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) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract A load switch circuit for turning on and off supply of DC power to a load circuit of a chromatograph apparatus, the load switch circuit comprising: a first switching element connected to between a first node that receives DC voltage and the load circuit, the first switching element including a control terminal that receives a potential of a second node; a capacitive element connected to between the first and second nodes; a first resistive element connected to between the first and second nodes; and a bypass circuit configured to pass current between the first and second nodes upon turn-off of the first switching element. ## Claims ### Claim 1 A chromatograph apparatus comprising: a plurality of operating sections configuring a chromatograph; and a load switch circuit configured to turn on and off supply of DC power, wherein at least one of the plurality of operating sections is connected as a load circuit to the load switch circuit, and the load switch circuit includes a first switching element connected between a first node that receives DC voltage and the load circuit, the first switching element having a control terminal that receives a potential of a second node, a capacitive element connected between the first and second nodes, a first resistive element connected between the first and second nodes, and a bypass circuit configured to pass current between the first and second nodes upon turn-off of the first switching element. ### Claim 2 (depends on 1) The chromatograph apparatus according to claim 1, wherein the bypass circuit includes a one-way continuity circuit configured to pass current from the first node to the second node upon the turn-off of the first switching element. ### Claim 3 (depends on 2) The chromatograph apparatus according to claim 2, wherein the load switch circuit further includes a second resistive element connected between the second node and a third node, and the one-way continuity circuit includes a third resistive element connected between the first and third nodes, and a diode connected between the third and second nodes. ### Claim 4 (depends on 3) The chromatograph apparatus according to claim 3, wherein the load switch circuit further includes a second switching element connected between the third node and a fourth node set at a reference potential, and a fourth resistive element connected between an anode of the diode and the second node. ### Claim 5 (depends on 1) The chromatograph apparatus according to claim 1, wherein the chromatograph includes an analytical column, a detector configured to detect constituents of a sample separated by the analytical column, and a power supply circuit, the detector includes the load switch circuit and the load circuit, and the load switch circuit is connected between the power supply circuit and the load circuit. ### Claim 6 (depends on 5) The chromatograph apparatus according to claim 5, wherein the load circuit includes a lamp lighting circuit, a motor driving circuit, or a heater driving circuit. ### Claim 7 A load switch circuit for turning on and off supply of DC power to a load circuit of a chromatograph apparatus, the load switch circuit comprising: a first switching element connected between a first node that receives DC voltage and the load circuit, the first switching element including a control terminal that receives a potential of a second node; a capacitive element connected between the first and second nodes; a first resistive element connected between the first and second nodes; and a bypass circuit configured to pass current between the first and second nodes upon turn-off of the first switching element. ### Claim 8 (depends on 7) The load switch circuit according to claim 7, wherein the bypass circuit includes a one-way continuity circuit configured to pass current from the first node to the second node upon the turn-off of the first switching element. ### Claim 9 (depends on 8) The load switch circuit according to claim 8, wherein the load switch circuit further includes a second resistive element connected between the second node and a third node, and the one-way continuity circuit includes a third resistive element connected between the first and third nodes, and a diode connected between the third and second nodes. ### Claim 10 (depends on 9) The load switch circuit according to claim 9, wherein the load switch circuit further includes a second switching element connected between the third node and a fourth node set at a reference potential, and a fourth resistive element connected between an anode of the diode and the second node.