# US 8,786,998 B2 · Electro-magnetic contactor and monitoring system of the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,998 B2 - Document ID: US8786998B2 - Status: Granted - Kind: B2 - Application number: 13/468,984 - Filed: 2012-05-10 - Published: 2012-11-29 - Granted: 2014-07-22 - Earliest claimed: 2011-05-25 - Assignees: Lsis Co., Ltd. - Applicants: Ki Bong Song - Inventors: Ki Bong Song - Web page: https://patentgrep.com/patent/US8786998B2 ## CPC - H01H 50/08: Indicators; Distinguishing marks - G01R 19/16595: {with multi level indication (G01R19/16519 and G01R19/16533 take precedence)} - 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 Disclosed herein is an electro-magnetic contactor and an electro-magnetic contactor monitoring system. The present disclosure may sense and display the status of input power that supplies electric energy to a power input end of the electro-magnetic contactor in real time, and when a failure occurs to generate a low voltage or over voltage, it may be sensed in real time to notify it to a user or the like, thereby allowing the user to monitor the status from a remote location. According to the present disclosure, it may be possible to prevent a load from being damaged by a fire due to a phenomenon of chattering in the electro-magnetic contactor, and eradicating a phenomenon that a coil of the contactor is damaged by a fire due to the over voltage, and minimizing losses that can be caused in a factory management system. ## Claims ### Claim 1 An electro-magnetic contactor for supplying or cutting off power to a load, the electro-magnetic contactor comprising: a status monitoring circuit configured to determine a status of input power, and display the status of the input power based on an input voltage of the input power that supplies electric energy to the electro-magnetic contactor; and a magnetic switching circuit connected to the input power in parallel to the status monitoring circuit, the magnetic switching circuit configured to receive the input voltage from the input power, and provided with an electromagnetic coil to supply power to a load while repeating a conducting state and a cut-off state wherein the status monitoring circuit comprises: an input voltage detection circuit connected to the input power and configured to detect the input voltage; a comparison circuit connected to an output of the input voltage detection circuit and configured to compare the detected input voltage with one or more preset reference voltages, and output the status of the input power according to a corresponding comparison result; a display connected to an output of the comparison circuit and configured to display the status of the input power outputted from the comparison circuit; a surge absorption circuit connected to the input power in parallel to the input voltage detection circuit, the surge absorption circuit configured to absorb a surge contained in the input voltage when the input voltage is an over voltage; and a constant voltage circuit having an input connected to an output of the surge absorption circuit, the constant voltage having an output connected to each of the input voltage detection circuit and the comparison circuit, the constant voltage circuit configured to rectify the input voltage to output a constant voltage, wherein the voltage detection circuit and the comparison circuit are each configured to operate in accordance with a signal from the constant voltage circuit. ### Claim 2 (depends on 1) The electro-magnetic contactor of claim 1, further comprising: a signal output circuit configured to convert the status of the input power into a status signal and output the converted status signal to an external device. ### Claim 3 (depends on 1) The electro-magnetic contactor of claim 1, wherein the status monitoring circuit displays one input power status among an over voltage, a rated voltage, and a low voltage. ### Claim 4 (depends on 1) The electro-magnetic contactor of claim 1, wherein the status monitoring circuit further comprises: a status storage unit configured to store the status of the input power. ### Claim 5 An electro-magnetic contactor monitoring system, comprising: an electro-magnetic contactor configured to supply power to a load while repeating a conducting state and a cut-off state; and a terminal connected to the electro-magnetic contactor via a wired or wireless communication link, the terminal configured to receive and display a status of input power that supplies electric energy to the electro-magnetic contactor, wherein the electro-magnetic contactor comprises a magnetic switching circuit connected to the input power to receive an input voltage from the input power and provided with an electromagnetic coil, and a status monitoring circuit connected to the input power in parallel to the magnetic switching circuit and configured to determine the status of the input power and to display the status of the input power, wherein the status monitoring circuit comprises: an input voltage detection circuit connected to the input power and configured to detect the input voltage; a comparison circuit connected to an output of the input voltage detection circuit and configured to compare the detected input voltage with one or more preset reference voltages, and output the status of the input power according to a corresponding comparison result; a display connected to an output of the comparison circuit and configured to display the status of the input power outputted from the comparison circuit; a surge absorption circuit connected to the input power in parallel to the input voltage detection circuit, the surge absorption circuit configured to absorb a surge contained in the input voltage when the input voltage is an over voltage; and a constant voltage circuit having an input connected to an output of the surge absorption circuit, the constant voltage having an output connected to each of the input voltage detection circuit and the comparison circuit, the constant voltage circuit configured to rectify the input voltage to output a constant voltage, wherein the voltage detection circuit and the comparison circuit are each configured to operate in accordance with a signal from the constant voltage circuit. ### Claim 6 (depends on 5) The electro-magnetic contactor monitoring system of claim 5, wherein the electro-magnetic contactor further comprises a signal output circuit configured to transmit the status of the input power. ### Claim 7 (depends on 5) The electro-magnetic contactor monitoring system of claim 5, wherein the status monitoring circuit further comprises: a status storage unit configured to store the status of the input power. ### Claim 8 (depends on 5) The electro-magnetic contactor monitoring system of claim 5, wherein the status monitoring circuit displays one input power status among an over voltage, a rated voltage, and a low voltage.