# US 2014/0196508 A1 · System and method for safely powering an appliance user interface without external power > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0196508 A1 - Document ID: US20140196508A1 - Status: Published application - Kind: A1 - Application number: 13/743,606 - Filed: 2013-01-17 - Published: 2014-07-17 - Earliest claimed: 2013-01-17 - Assignees: General Electric Company - Applicants: General Electric Company - Inventors: Scott Michael Gelber; Steven Michael Recio; Richard D. Suel, II; Jonathan Blair Talmadge; Heather Rae Posthauer; Ryan James Scheckelhoff; Abhijeet A. Bhandwale; Byron Lee Boylston - Web page: https://patentgrep.com/patent/US20140196508A1 ## CPC - D06F 37/30: Driving arrangements (control circuits or arrangements D06F34/08) - D06F 37/42: Safety arrangements, e.g. for stopping rotation of the receptacle upon opening of the casing door - D06F 34/10: Power supply arrangements, e.g. stand-by circuits - D06F: LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES ## Abstract Systems and methods for safely powering an appliance user interface without external power are provided. One exemplary method includes receiving power generated by rotation of a rotor. The method further includes monitoring for the presence of a safety condition and disabling passive braking of the rotor when the safety condition is present such that the user interface of an appliance is powered. An exemplary washing machine can include a basket and a motor which includes a rotor, the motor being configured to rotate the basket by rotating the rotor. The washing machine can further include a user interface and a motor control circuit configured to drive the motor. The motor control circuit can be further configured to receive power generated by rotation of the rotor, monitor for the presence of a safety condition, and disable passive braking of the rotor when the safety condition is present. ## Claims ### Claim 1 A method for safely powering a user interface of an appliance, the method comprising: receiving power generated by rotation of a rotor, the rotor being an element of a motor of the appliance; monitoring for the presence of a safety condition; and disabling passive braking of the rotor when the safety condition is present such that the user interface of the appliance is powered. ### Claim 2 (depends on 1) The method of claim 1, wherein the method further comprises enabling passive braking of the rotor while monitoring for the presence of the safety condition. ### Claim 3 (depends on 1) The method of claim 1, wherein the method further comprises enabling passive braking of the rotor when the safety condition is no longer present. ### Claim 4 (depends on 1) The method of claim 1, wherein the safety condition requires an absence of externally supplied power. ### Claim 5 (depends on 3) The method of claim 3, wherein the safety condition requires a rotor rotation speed less than a threshold speed. ### Claim 6 (depends on 1) The method of claim 1, wherein monitoring for the presence of a safety condition comprises monitoring for the presence of a first safety condition, the method further comprising: monitoring for the presence of a second safety condition; and disabling passive braking of the rotor when both the first and second safety conditions are present. ### Claim 7 (depends on 6) The method of claim 6, wherein: the first safety condition requires an absence of externally supplied power; and the second safety condition requires a door of the appliance to be open. ### Claim 8 (depends on 1) The method of claim 1, wherein disabling passive braking of the rotor comprises disabling a gate driver configured to drive the motor. ### Claim 9 (depends on 1) The method of claim 1, further comprising operating the appliance in a demonstration mode. ### Claim 10 A washing machine comprising: a basket; a motor which includes a rotor, the motor being configured to rotate the basket by rotating the rotor; a user interface; and a motor control circuit configured to drive the motor; wherein the motor control circuit is further configured to receive power generated by rotation of the rotor, monitor for the presence of a safety condition, and disable passive braking of the rotor when the safety condition is present. ### Claim 11 (depends on 10) The washing machine of claim 10, wherein the motor control circuit is configured to apply passive braking to the rotor upon initialization. ### Claim 12 (depends on 10) The washing machine of claim 10, wherein the motor control circuit comprises a gate driver configured to drive the motor and a processor configured to control the gate driver, the processor being configured to disable passive braking of the rotor by disabling the gate driver. ### Claim 13 (depends on 12) The washing machine of claim 12, wherein the gate driver drives the motor by switching a plurality of switching elements, the plurality of switching elements being configured to apply passive braking to the rotor upon initialization. ### Claim 14 (depends on 13) The washing machine of claim 13, further comprising a plurality of resistors configured to ensure that passive braking is applied to the rotor upon initialization. ### Claim 15 (depends on 10) The washing machine of claim 10, wherein the motor control circuit is further configured to apply passive braking to the rotor when the safety condition is no longer present. ### Claim 16 (depends on 15) The washing machine of claim 15, wherein the safety condition requires a rotor rotation speed less than a threshold speed. ### Claim 17 (depends on 15) The washing machine of claim 15, wherein the washing machine further comprises a connection for receiving externally supplied power, the safety condition requiring the absence of externally supplied power. ### Claim 18 (depends on 10) The washing machine of claim 10, wherein the user interface operates in a demonstration mode when the safety condition is present. ### Claim 19 A motor control circuit configured to drive a motor having a rotor, the motor control circuit comprising: a DC bus, the DC bus being configured to be charged when the rotor is rotated; a gate driver, the gate driver being configured to apply passive braking to the rotor upon initialization; an AC line sensor configured to sense the presence of externally supplied AC power; and a user interface, the user interface receiving power from the DC bus after passive braking of the rotor is disabled. ### Claim 20 (depends on 19) The motor control circuit of claim 19, further comprising a processor configured to disable the gate driver when the DC bus is charged and the AC line sensor senses that externally supplied AC power is not present.