# US 2014/0190083 A1 · System and method for determining appliance door status > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190083 A1 - Document ID: US20140190083A1 - Status: Published application - Kind: A1 - Application number: 13/735,247 - Filed: 2013-01-07 - Published: 2014-07-10 - Earliest claimed: 2013-01-07 - Assignees: General Electric Company - Applicants: General Electric Company - Inventors: David H. Lepie - Web page: https://patentgrep.com/patent/US20140190083A1 ## CPC - A47L 15/4259: {Arrangements of locking or security/safety devices for doors, e.g. door latches, switch to stop operation when door is open} - E05B 43/00: Time locks - E05B 43/005: {Timer devices controlling electrically operated locks} - E05B 47/0012: {with rotary electromotors (actuators with rotary electromotors per se H02K7/06, H02K23/68)} - A47L 15/0049: {Detection or prevention of malfunction, including accident prevention (arrangements to prevent clogging of filters A47L15/4208; safety arrangements for preventing water damage A47L15/421)} - A47L 2401/26: Loading door status, e.g. door latch opened or closed state - A47L 2501/26: Indication or alarm to the controlling device or to the user - D06F 34/20: Parameters relating to constructional components, e.g. door sensors - D06F 37/42: Safety arrangements, e.g. for stopping rotation of the receptacle upon opening of the casing door - D06F 39/14: Doors or covers; Securing means therefor - D06F 2103/40: Opening or locking status of doors - E05B 2047/0068: {Door closed} - E05B 2047/0069: {bolt position} - F24C 15/02: Doors specially adapted for stoves or ranges - F24C 15/022: {Latches} - A47L: DOMESTIC WASHING OR CLEANING (brushes A46B; cleaning quantities of bottles or of other hollow articles of one kind B08B9/00; laundry D06F); SUCTION CLEANERS IN GENERAL (cleaning in general B08) - E05B: LOCKS; ACCESSORIES THEREFOR; HANDCUFFS - D06F: LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES - F24C: DOMESTIC STOVES OR RANGES (exclusively for solid fuels F24B); DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION ## Abstract A system and method of determining the status of an appliance door is provided. The status of the door of the appliance can be determined based an output signal provided by a door switch coupled in series with a latch motor feedback. A change in the output signal of the door switch can be indicative of either the opening of the appliance door or the actuating of the latch motor. The source of the change in an output of the door switch can be determined based on the latch command provided to the latch motor. The appliance can be controlled based on the status of the appliance door. ## Claims ### Claim 1 A control system for an appliance, the appliance comprising an appliance door, the control system comprising: a door lock latch movable between a locked position and an unlocked position, the door lock latch configured to prevent opening of the appliance door when in the locked position; a latch motor configured to drive the door lock latch between the locked position and the unlocked position; a motor feedback providing a signal indicative of a state of the latch motor; a door switch coupled in series with the motor feedback; and a controller configured to receive an output signal from the door switch coupled in series with the motor feedback; wherein the controller is capable of determining a state of the appliance door based at least in part on the output signal from the door switch. ### Claim 2 (depends on 1) The control system of claim 1, wherein the controller is configured to determine whether the appliance door is an open state or a closed state. ### Claim 3 (depends on 1) The control system of claim 1, wherein the controller provides a control input to the latch motor, the control input providing at least one latch command driving the motor to a lock state or to an unlock state. ### Claim 4 (depends on 3) The control system of claim 3, wherein the controller is configured to determine the state of the appliance door based at least in part on the output signal from the door switch and the latch command. ### Claim 5 (depends on 4) The control system of claim 4, wherein the controller is configured to determine the state of the appliance door based at least in part on a change in the output signal from the door switch. ### Claim 6 (depends on 5) The control system of claim 5, wherein the controller is configured to determine the state of the appliance door based at least in part on a change in the latch command and the lapse of a time interval. ### Claim 7 (depends on 1) The control system of claim 1, wherein the motor feedback is provided by a motor switch associated with the latch motor. ### Claim 8 (depends on 3) The control system of claim 3, wherein the control input comprises a lock input for providing a lock command to the latch motor and an unlock input for providing an unlock command to the latch motor. ### Claim 9 (depends on 1) The control system of claim 1, wherein the motor feedback is provided from a first motor switch and a second motor switch associated with the latch motor, the first motor switch configured to close when the latch motor is in a lock state and the second motor switch configured to close when the latch motor is in an unlock state. ### Claim 10 (depends on 1) The control system of claim 1, wherein the first motor switch and the second motor switch are configured to be closed by a rotating cam of the latch motor. ### Claim 11 (depends on 1) The control system of claim 1, wherein the controller is configured to control the appliance based on the state of the appliance door. ### Claim 12 (depends on 1) The control system of claim 1, wherein the appliance comprises a second appliance door, the control system comprising: a second door lock latch movable between a locked position and an unlocked position, the second door lock latch configured to prevent opening of the second appliance door when in the locked position; a second latch motor configured to drive the second door lock latch between the locked position and the unlocked position; a second motor feedback providing a signal indicative of a drive state of the second latch motor; and a second door switch coupled in series the second motor feedback, the second door switch providing an output signal to the controller. ### Claim 13 (depends on 12) The control system of claim 12, wherein the controller is configured to provide a common control input to the latch motor and the second latch motor. ### Claim 14 (depends on 12) The control system of claim 12, wherein the controller is configured to determine a state of the second appliance door based on the output signal from the second door switch and a latch command provided to the second latch motor via the common control input. ### Claim 15 A method of determining the state of an appliance door, the method comprising: receiving, at a controller, an output signal of a door switch associated with the appliance door, the door switch coupled in series with a latch motor feedback, the latch motor feedback providing a signal indicative of a state of a latch motor capable of actuating a door latch between a lock position and an unlock position, the door latch configured to prevent opening of the appliance door when in a lock position; identifying a latch command provided by the controller to the latch motor; and determining a state of the appliance door based at least in part on the output signal of the door switch and the latch command. ### Claim 16 (depends on 15) The method of claim 15, wherein determining a state of the appliance door based at least in part on the output signal of the door switch and the latch command comprises: detecting a change in the output signal; determining that the latch command provided to the motor has not changed; and determining that the state of the appliance door has changed. ### Claim 17 (depends on 15) The method of claim 15, wherein determining a state of the appliance door based at least in part on the output signal of the door switch and the latch command comprises: detecting a change in the output signal from a first signal state to a second signal state; identifying a change in the latch command provided to the latch motor; waiting for the lapse of a time interval; and determining that the state of the appliance door has changed when the output signal remains in the second signal state after the lapse of the time interval. ### Claim 18 (depends on 15) The method of claim 15, wherein the method further comprises controlling the appliance based at least in part on the state of the appliance door. ### Claim 19 An appliance, comprising: an appliance door; a door lock latch movable between a locked position and an unlocked position, the door lock latch configured to prevent opening of the appliance door when in the locked position; a latch motor configured to drive the door lock latch between the locked position and the unlocked position; a motor feedback providing a signal indicative of a state of the latch motor; a door switch coupled in series with the motor feedback; and a controller configured to receive an output signal from the door switch coupled in series with the motor feedback; wherein the controller is capable of determining a state of the appliance door based at least in part on the output signal from the door switch. ### Claim 20 (depends on 19) The appliance of claim 19, wherein the controller provides a control input to the latch motor, the control input providing at least one latch motor command driving the motor to a lock state or to an unlock state, the controller configured to determine the state of the appliance door based at least in part on the output signal from the door switch and the latch motor command.