# US 2013/0278181 A1 · Reverse Rotation of a Motor Configured for Operation in a Forward Direction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0278181 A1 - Document ID: US20130278181A1 - Status: Published application - Kind: A1 - Application number: 13/851,812 - Filed: 2013-03-27 - Published: 2013-10-24 - Earliest claimed: 2012-04-23 - Assignees: International Rectifier Corporation - Applicants: International Rectifier Corporation - Inventors: Marco Palma - Web page: https://patentgrep.com/patent/US20130278181A1 ## CPC - H02P 6/22: in a selected direction of rotation - H02P 6/26: Arrangements for controlling single phase motors - H02P 23/24: Controlling the direction, e.g. clockwise or counterclockwise - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract There are disclosed herein various implementations of a method and a system enabling operation of a motor in reverse. Such a method includes applying a first drive signal to begin rotating the motor in a reverse direction, the first drive signal being applied for a predetermined period of time. The method also includes using a position sensor signal for the motor to control motor drive in the reverse direction when the motor reaches a predetermined reverse speed, and operating the motor in the reverse direction. ## Claims ### Claim 1 A method enabling operation of a motor, said method comprising: applying a first drive signal to begin rotating said motor in a reverse direction, said first drive signal being applied for a predetermined period of time; using a position sensor signal for said motor to control motor drive in said reverse direction when said motor reaches a predetermined reverse speed; operating said motor in said reverse direction. ### Claim 2 (depends on 1) The method of claim 1, wherein said motor is configured to operate in a forward direction opposite said reverse direction. ### Claim 3 (depends on 1) The method of claim 1, further comprising identifying an angular orientation of said motor and applying said first drive signal based on said angular orientation. ### Claim 4 (depends on 1) The method of claim 1, further comprising sensing a change in an angular orientation of said motor in said reverse direction after application of said first drive signal, and applying a second drive signal to continue rotating said motor in said reverse direction based on said change in said angular orientation. ### Claim 5 (depends on 4) The method of claim 4, wherein said second drive signal is applied for said predetermined period of time. ### Claim 6 (depends on 1) The method of claim 1, wherein said motor is a single phase alternating current (AC) motor. ### Claim 7 (depends on 1) The method of claim 1, wherein using said position sensor signal to control motor drive in said reverse direction comprises phase shifting said position sensor signal to generate a motor control signal for driving said motor in said reverse direction. ### Claim 8 (depends on 1) The method of claim 1, wherein said position sensor signal comprises a Hall sensor signal. ### Claim 9 (depends on 1) The method of claim 1, wherein drive signals used to operate said motor in said reverse direction have a substantially constant duty cycle. ### Claim 10 A system enabling operation of a motor, said system comprising: a motor configured to operate in a forward direction opposite a reverse direction; a motor controller coupled to said motor, said motor controller configured to: apply a first drive signal to begin rotating said motor in said reverse direction, said first drive signal being applied for a predetermined period of time; use a position sensor signal for said motor to control motor drive in said reverse direction when said motor reaches a predetermined reverse speed, thereby operating said motor in said reverse direction. ### Claim 11 (depends on 10) The system of claim 10, wherein said motor controller is further configured to identify an angular orientation of said motor and to apply said first drive signal based on said angular orientation. ### Claim 12 (depends on 10) The system of claim 10, wherein said motor controller is further configured to sense a change in an angular orientation of said motor in said reverse direction after application of said first drive signal, and to apply a second drive signal to continue rotating said motor in said reverse direction based on said change in said angular orientation. ### Claim 13 (depends on 12) The system of claim 12, wherein said second drive signal is applied for said predetermined period of time. ### Claim 14 (depends on 10) The system of claim 10, wherein said motor is a single phase alternating current (AC) motor. ### Claim 15 (depends on 10) The system of claim 10, wherein said motor controller is implemented as an integrated circuit (IC). ### Claim 16 (depends on 10) The system of claim 10, wherein said motor controller is configured to phase shift said position sensor signal, thereby generating a motor control signal for controlling said motor drive in said reverse direction. ### Claim 17 (depends on 10) The system of claim 10, wherein said position sensor signal comprises a Hall sensor signal. ### Claim 18 (depends on 10) The system of claim 10, wherein drive signals used to operate said motor in said reverse direction have a substantially constant duty cycle.