# US 11,994,565 B2 · Potential difference early-warning circuit and system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,994,565 B2 - Document ID: US11994565B2 - Status: Granted - Kind: B2 - Application number: 18/043,972 - Filed: 2021-07-30 - Published: 2023-09-14 - Granted: 2024-05-28 - Earliest claimed: 2020-09-04 - Assignees: Inspur Suzhou Intelligent Technology Co., Ltd. - Applicants: Inspur Suzhou Intelligent Technology Co., Ltd. - Inventors: Jie Cui; Lemei Bao - Web page: https://patentgrep.com/patent/US11994565B2 ## CPC - G01R 19/10: Measuring sum, difference or ratio - G01R 31/52: Testing for short-circuits, leakage current or ground faults - G01R 19/16547: {voltage or current in AC supplies (switching for protection H02H; circuits for emergency power supply H02J9/00)} - G01R 19/16571: {comparing AC or DC current with one threshold, e.g. load current, over-current, surge current or fault current (G01R19/16514, G01R19/16519, G01R19/16528, G01R19/16533, G01R19/1659 take precedence; measuring currents by using elements sensitive to the magnetic field generated G01R15/14; measuring earth resistance G01R27/18; testing for leakage or short circuits in electrical apparatus G01R31/52)} - G01R 31/2801: {Testing of printed circuits, backplanes, motherboards, hybrid circuits or carriers for multichip packages [MCP] (G01R31/318508 takes precedence; contactless testing G01R31/302; testing contacts or connections G01R31/66)} - G01R 31/50: Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections (testing of sparking plugs H01T13/58) - H02H 3/26: responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents - G01R 19/16576: {comparing DC or AC voltage with one threshold (G01R19/16514, G01R19/16519, G01R19/16528, G01R19/16533 and G01R19/1659 take precedence)} - H02H 5/105: {responsive to deterioration or interruption of earth connection (for preventing switching-on H02H11/001)} - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - 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) ## Abstract A potential difference early-warning circuit, comprising: a sensing resistor (R2), (PCB GND); a first MOS (M1), a drain of the first MOS being connected to the sensing resistor (R2), and a source of the first MOS (M1) being connected to a safety ground (GND); an operational amplifier (U1A), a positive input end of the operational amplifier being connected to one end of the sensing resistor (R2), and a negative input end of the operational amplifier (U1A) being connected to the other end of the sensing resistor (R2); a second MOS (M2), a gate of the second MOS (M2) being connected to an output end of the operational amplifier (U1A), and a source of the second MOS (M2) being connected to the signal ground; and a controller, a first input end of the controller being connected to the drain of the second MOS (M2), and an output end of the controller being connected to the gate of the second MOS (M2). ## Claims ### Claim 1 A potential difference early-warning circuit, comprising: a sensing resistor, one end of the sensing resistor being connected to a signal ground; a first Metal-Oxide-Semiconductor Field-Effect Transistor (MOS), a drain of the first MOS being connected to the other end of the sensing resistor, and a source of the first MOS being connected to a safety ground; an operational amplifier, a positive input end of the operational amplifier being connected to one end of the sensing resistor, and a negative input end of the operational amplifier being connected to the other end of the sensing resistor; a second MOS, a gate of the second MOS being connected to an output end of the operational amplifier, and a source of the second MOS being connected to the signal ground; and a controller, a first input end of the controller being connected to the drain of the second MOS, and an output end of the controller being connected to the gate of the second MOS; wherein the operational amplifier is configured to send a corresponding level to the second MOS according to a magnitude of a potential difference between the signal ground and the safety ground, so as to control the second MOS to be turned on or turned off, so that the controller receives the corresponding level through the first input end, and then the controller controls the first MOS to be turned on or turned off according to the received level. ### Claim 2 (depends on 1) The potential difference early-warning circuit as claimed in claim 1, wherein the operational amplifier is further configured to send, in response to the potential difference between the signal ground and the safety ground reaching a threshold, a high level to the second MOS to control the second MOS to be turned on, so that the first input end of the controller is connected to the signal ground, and the controller receives a low level, and the controller outputs the low level through the output end of the controller, thereby turning off the first MOS. ### Claim 3 (depends on 1) The potential difference early-warning circuit as claimed in claim 1, further comprising: a first power supply, connected to a power supply end of the operational amplifier; and a first current-limiting resistor, one end of the first current-limiting resistor being connected to the first power supply, and the other end of the first current-limiting resistor being connected to the first input end of the controller. ### Claim 4 (depends on 3) The potential difference early-warning circuit as claimed in claim 3, wherein the operational amplifier is further configured to send, in response to the potential difference between the signal ground and the safety ground not reaching a threshold, a low level to the second MOS to control the second MOS to be turned off, so that a first input end of the controller receives a high level, and outputs a high level through an output end of the controller, thereby turning on the first MOS according to the high level. ### Claim 5 (depends on 1) The potential difference early-warning circuit as claimed in claim 1, further comprising: a triode, a base of the triode being connected to the signal ground, a collector of the triode being connected to a second input end of the controller, and an emitter of the triode being connected to the safety ground; wherein the triode is configured to be turned on or turned off according to whether there is a potential difference between the signal ground and the safety ground, so that the second input end of the controller receives a corresponding level. ### Claim 6 (depends on 5) The potential difference early-warning circuit as claimed in claim 5, wherein the triode is further configured to be turned on when there is the potential difference between the signal ground and the safety, so as to make the second input end of the controller be connected to the signal ground, so that the controller prompts, after receiving a low level input by the second input end, that there is the potential difference between the current signal ground and the safety ground. ### Claim 7 (depends on 5) The potential difference early-warning circuit as claimed in claim 5, further comprising: a second power supply connected to the collector of the triode; and a pull-up resistor, one end of the pull-up resistor being connected to the second power supply, and the other end of the pull-up resistor being connected to the collector of the triode. ### Claim 8 (depends on 7) The potential difference early-warning circuit as claimed in claim 7, wherein the triode is further configured to be turned off when there is no potential difference between the signal ground and the safety ground, so that the second input end of the controller receives a high level. ### Claim 9 (depends on 5) The potential difference early-warning circuit as claimed in claim 5, further comprising: a second current-limiting resistor, one end of the second current-limiting resistor being connected to the base of the triode, and the other end of the second current-limiting resistor being connected to the signal ground. ### Claim 10 A potential difference early-warning system, comprising the potential difference early-warning circuit; wherein the potential difference early-warning circuit comprises: a sensing resistor, one end of the sensing resistor being connected to a signal ground; a first Metal-Oxide-Semiconductor Field-Effect Transistor (MOS), a drain of the first MOS being connected to the other end of the sensing resistor, and a source of the first MOS being connected to a safety ground; an operational amplifier, a positive input end of the operational amplifier being connected to one end of the sensing resistor, and a negative input end of the operational amplifier being connected to the other end of the sensing resistor; a second MOS, a gate of the second MOS being connected to an output end of the operational amplifier, and a source of the second MOS being connected to the signal ground; and a controller, a first input end of the controller being connected to the drain of the second MOS, and an output end of the controller being connected to the gate of the second MOS; wherein the operational amplifier is configured to send a corresponding level to the second MOS according to a magnitude of a potential difference between the signal ground and the safety ground, so as to control the second MOS to be turned on or turned off, so that the controller receives the corresponding level through the first input end, and then the controller controls the first MOS to be turned on or turned off according to the received level. ### Claim 11 (depends on 2) The potential difference early-warning circuit as claimed in claim 2, wherein determine the potential difference through the potentials at two ends of the sensing resistor. ### Claim 12 (depends on 2) The potential difference early-warning circuit as claimed in claim 2, wherein when the potential difference between the signal ground and the safety ground reaching the threshold, the operational amplifier sends a high level to the second MOS; the second MOS is turned on after receiving the high level, and outputs a low level, so that the controller receives the low level. ### Claim 13 (depends on 1) The potential difference early-warning circuit as claimed in claim 1, wherein the second MOS is to provide a low level input or a high level input for the controller. ### Claim 14 (depends on 4) The potential difference early-warning circuit as claimed in claim 4, wherein when the potential difference between the signal ground and the safety ground does not reach the threshold, the operational amplifier sends a low level to the second MOS; the second MOS is turned off after receiving the low level, and outputs a high level, so that the controller receives the high level. ### Claim 15 (depends on 1) The potential difference early-warning circuit as claimed in claim 1, wherein when a low level is detected at the second input end of the controller and the low level is still detected after a delay of preset time, determining whether the low level is still detected at the first input end of the controller; when the low level is detected at the first input end of the controller and the low level is detected after a delay of the preset time, the controller outputs the low level to turn off the first MOS. ### Claim 16 (depends on 10) The potential difference early-warning system as claimed in claim 10, wherein the operational amplifier is further configured to send, in response to the potential difference between the signal ground and the safety ground reaching a threshold, a high level to the second MOS to control the second MOS to be turned on, so that the first input end of the controller is connected to the signal ground, and the controller receives a low level, and the controller outputs the low level through the output end of the controller, thereby turning off the first MOS. ### Claim 17 (depends on 10) The potential difference early-warning system as claimed in claim 10, further comprising: a first power supply, connected to a power supply end of the operational amplifier; and a first current-limiting resistor, one end of the first current-limiting resistor being connected to the first power supply, and the other end of the first current-limiting resistor being connected to the first input end of the controller. ### Claim 18 (depends on 10) The potential difference early-warning system as claimed in claim 10, wherein the operational amplifier is further configured to send, in response to the potential difference between the signal ground and the safety ground not reaching a threshold, a low level to the second MOS to control the second MOS to be turned off, so that a first input end of the controller receives a high level, and outputs a high level through an output end of the controller, thereby turning on the first MOS according to the high level. ### Claim 19 (depends on 10) The potential difference early-warning system as claimed in claim 10, further comprising: a triode, a base of the triode being connected to the signal ground, a collector of the triode being connected to a second input end of the controller, and an emitter of the triode being connected to the safety ground; wherein the triode is configured to be turned on or turned off according to whether there is a potential difference between the signal ground and the safety ground, so that the second input end of the controller receives a corresponding level. ### Claim 20 (depends on 10) The potential difference early-warning system as claimed in claim 10, wherein the triode is further configured to be turned on when there is the potential difference between the signal ground and the safety, so as to make the second input end of the controller be connected to the signal ground, so that the controller prompts, after receiving a low level input by the second input end, that there is the potential difference between the current signal ground and the safety ground.