# US 2016/0087560 A1 · Dc motor control over wide dynamic range > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0087560 A1 - Document ID: US20160087560A1 - Status: Published application - Kind: A1 - Application number: 14/494,951 - Filed: 2014-09-24 - Published: 2016-03-24 - Earliest claimed: 2014-09-24 - Assignees: Process Control Corporation - Applicants: Process Control Corporation - Inventors: Lloyd Miller - Web page: https://patentgrep.com/patent/US20160087560A1 ## CPC - H02P 6/06: Arrangements for speed regulation of a single motor wherein the motor speed is measured and compared with a given physical value so as to adjust the motor speed - H02P 6/085: {in a bridge configuration} - H02P 6/17: and for generating speed information - H02P 6/28: Arrangements for controlling current (H02P6/10 takes precedence) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS ## Abstract Various examples are provided for brushless direct current (DC) motor control over a wide dynamic range. In one example, among others, a system including a power drive coupled to a DC motor and a MCU configured to control commutation of the DC motor based upon shaft speed of the DC motor, where the MCU transitions between a motion-based commutation mode and a time-based commutation mode in response to a comparison of the shaft speed with a predefined threshold. In another example, a method includes commutating a DC motor in response to a transition in rotor position of the DC motor and transitioning from a motion-based commutation mode to a time-based commutation mode in response to a comparison of shaft speed of the DC motor to a predefined threshold. ## Claims ### Claim 1 A system for control of direct current (DC) motors, comprising: a power drive coupled to a brushless DC motor; and a micro control unit (MCU) configured to control commutation of the brushless DC motor based upon shaft speed of the brushless DC motor, where the MCU transitions between a motion-based commutation mode and a time-based commutation mode in response to a comparison of the shaft speed with a predefined threshold. ### Claim 2 (depends on 1) The system of claim 1, wherein the time-based commutation mode commutates the brushless DC motor in response to expiration of a timer having a period corresponding to a desired shaft speed. ### Claim 3 (depends on 2) The system of claim 2, wherein current supplied to the brushless DC motor is adjusted based upon a rotor position of the brushless DC motor at the expiration of the timer. ### Claim 4 (depends on 3) The system of claim 3, wherein the rotor position is based upon signals from Hall Effect sensors of the brushless DC motor. ### Claim 5 (depends on 4) The system of claim 4, further comprising an input isolation boundary configured to isolate outputs of the Hall Effect sensors from the MCU. ### Claim 6 (depends on 3) The system of claim 3, wherein the current supplied to the brushless DC motor is increased in response to an insufficient change in the rotor position. ### Claim 7 (depends on 1) The system of claim 1, further comprising an output isolation boundary configured to isolate outputs of the MCU from gate drive circuitry of the power drive. ### Claim 8 (depends on 1) The system of claim 1, further comprising a current limiter configured to provide an indication to the MCU that load current exceeds a predefined limit. ### Claim 9 (depends on 8) The system of claim 8, wherein the current limiter comprises a selectable voltage divider to set the predefined limit. ### Claim 10 (depends on 1) The system of claim 1, wherein the motion-based commutation mode commutates the brushless DC motor in response to a predefined change in rotor position of the brushless DC motor. ### Claim 11 (depends on 10) The system of claim 10, wherein the commutation of the brushless DC motor is in response to a transition in a signal from a Hall Effect sensor of the brushless DC motor. ### Claim 12 (depends on 1) The system of claim 1, further comprising a watchdog timer configured to initiate a motor stall protocol if the watchdog timer expires before a next Hall Effect signal transition occurs, where the watchdog timer is reset at a Hall Effect signal transition preceding the next Hall Effect signal transition. ### Claim 13 (depends on 1) The system of claim 1, wherein the system is further configured to control commutation of a brushed DC motor when coupled to the power drive. ### Claim 14 A method, comprising: commutating, in a motion-based commutation mode, a brushless DC motor by switching a power drive coupled to the brushless DC motor in response to a transition in rotor position of the brushless DC motor; comparing a shaft speed of the brushless DC motor to a predefined threshold; and transitioning to a time-based commutation mode in response to the comparison. ### Claim 15 (depends on 14) The method of claim 14, further comprising determining the shaft speed based upon signals from Hall Effect sensors of the brushless DC motor. ### Claim 16 (depends on 14) The method of claim 14, further comprising initiating a commutation timer in response to the transition to the time-based commutation mode. ### Claim 17 (depends on 16) The method of claim 16, further comprising adjusting current supplied to the DC motor during commutation based upon rotor position of the brushless DC motor. ### Claim 18 (depends on 17) The method of claim 17, further comprising commutating the brushless DC motor by switching the power drive in response to timeout of the commutation timer. ### Claim 19 (depends on 14) The method of claim 14, further comprising transitioning from the time-based commutation mode to the motion-based commutation mode in response to a subsequent comparison of shaft speed to the predefined threshold. ### Claim 20 (depends on 14) The method of claim 14, further comprising transitioning from the time-based commutation mode to the motion-based commutation mode in response to a subsequent comparison of shaft speed to a second predefined threshold.