# US 10,121,621 B2 · Controller for confirming contact status and controlling contact of latch relay in electric power meter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,121,621 B2 - Document ID: US10121621B2 - Status: Granted - Kind: B2 - Application number: 15/057,377 - Filed: 2016-03-01 - Published: 2016-09-15 - Granted: 2018-11-06 - Earliest claimed: 2015-03-12 - Assignees: Lsis Co., Ltd. - Applicants: Lsis Co., Ltd. - Inventors: Hyungkyu Kim - Web page: https://patentgrep.com/patent/US10121621B2 ## CPC - H01H 47/001: {Functional circuits, e.g. logic, sequencing, interlocking circuits} - G01R 31/327: Testing of circuit interrupters, switches or circuit-breakers - G01R 31/3278: {of relays, solenoids or reed switches (measuring contact resistance G01R27/205; high voltage magnetic switches G01R31/3271, G01R31/333; testing electric windings G01R31/72; monitoring of fail safe circuits H01H47/002)} - H01H 50/08: Indicators; Distinguishing marks - G01R 21/133: by using digital technique - H01H 9/167: {Circuits for remote indication} - H01H 47/002: {Monitoring or fail-safe circuits} - H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A controller for confirming the contact status of a latch relay embedded in an electric power meter according to the invention includes a microcomputer unit that is electrically connected to the latch relay for reading and providing the contact switching status information of the latch relay during a power failure, and read the contact switching status information stored during the power failure when a power recovers, and configured to output an opening control signal to the latch relay when the read contact switching status is an open state, and configured to output a closing control signal to the latch relay when the read contact switching status is a closed state; and a non-volatile memory that stores the contact switching status information of the latch relay provided by the microcomputer unit or provides the contact switching status information of the latch relay to the microcomputer unit during a power failure. ## Claims ### Claim 1 A controller for confirming a contact status of a latch relay embedded in an electric power meter, comprising: a microcomputer unit that is electrically connected to the latch relay for reading and providing a contact switching status information of the latch relay to store when a power failure occurs, and read the contact switching status information stored during the power failure when a power recovers, and configured to output an opening control signal to the latch relay when the read contact switching status is an open state, and configured to output a closing control signal to the latch relay when the read contact switching status is a closed state; and a non-volatile memory that stores the contact switching status information of the latch relay provided by the microcomputer unit or provides the contact switching status information of the latch relay to the microcomputer unit during the power failure. ### Claim 2 (depends on 1) The controller of claim 1, wherein the microcomputer unit is configured to output the opening control signal to the latch relay when the read contact switching status information is the open state, and configured to output the closing control signal to the latch relay when the read contact switching status information is the closed state according to the contact switching status information read from the non-volatile memory during the power failure. ### Claim 3 (depends on 1) The controller of claim 1, wherein the microcomputer unit is configured to sense an input voltage and an output voltage of the embedded latch relay when the power recovers or in a state that the electric power meter is separated from a normal installation location and then reinstalled and an electric power is supplied again to the electric power meter, configured to determine the contact of the embedded latch relay as the closed state when the sensed input voltage of the embedded latch relay is substantially the same as the output voltage thereof, and configured to determine the contact of the embedded latch relay as the open state when there exists the input voltage input but does not exist the output voltage input. ### Claim 4 (depends on 3) The controller of claim 3, wherein the microcomputer unit is configured to output the opening control signal to the latch relay when the sensed contact switching status information represents the open state, and outputs the closing control signal to the latch relay when the sensed contact switching status information represents the closed state according to the sensed contact switching status information. ### Claim 5 (depends on 3) The controller of claim 3, further comprising a voltage detection device connected to an input terminal and an output terminal of the embedded latch relay, respectively, to detect the input voltage and output voltage of the embedded latch relay. ### Claim 6 (depends on 5) The controller of claim 5, wherein the voltage detection device is configured with a voltage dividing resistor connected to the input terminal and the output terminal of the embedded latch relay, respectively. ### Claim 7 (depends on 5) The controller of claim 5, wherein the voltage detection device is configured with a potential transformer connected to the input terminal and the output terminal of the embedded latch relay, respectively.