Patents by Inventor Ward R. Brown
Ward R. Brown has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11018606Abstract: Low cost linear Hall Effect sensors are used for determining motor shaft positions and generating voltages proportional to the motor shaft positions. The voltages from the linear Hall Effect sensors are compared to a triangle waveform and PWM signals are generated therefrom. A constant current source and constant current sink are used in the triangle waveform generator. The voltages from the linear Hall Effect sensors are adjusted to change the PWM duty cycles used to startup and vary the speed of the motor. Comparators compare the voltages from the Hall Effect sensors and product the PWM signals having duty cycles proportional to the voltage drive requirements of the motor.Type: GrantFiled: January 9, 2019Date of Patent: May 25, 2021Assignee: MICROCHIP TECHNOLOGY INCORPORATEDInventors: Ward R. Brown, Howard Hendricks
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Publication number: 20190149071Abstract: Low cost linear Hall Effect sensors are used for determining motor shaft positions and generating voltages proportional to the motor shaft positions. The voltages from the linear Hall Effect sensors are compared to a triangle waveform and PWM signals are generated therefrom. A constant current source and constant current sink are used in the triangle waveform generator. The voltages from the linear Hall Effect sensors are adjusted to change the PWM duty cycles used to startup and vary the speed of the motor. Comparators compare the voltages from the Hall Effect sensors and product the PWM signals having duty cycles proportional to the voltage drive requirements of the motor.Type: ApplicationFiled: January 9, 2019Publication date: May 16, 2019Applicant: Microchip Technology IncorporatedInventors: Ward R. Brown, Howard Hendricks
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Patent number: 10135369Abstract: Low cost linear Hall Effect sensors are used for determining motor shaft positions and generating voltages proportional to the motor shaft positions. The voltages from the linear Hall Effect sensors are compared to a triangle waveform and PWM signals are generated therefrom. A constant current source and constant current sink are used in the triangle waveform generator. The voltages from the linear Hall Effect sensors are adjusted to change the PWM duty cycles used to startup and vary the speed of the motor. Comparators compare the voltages from the Hall Effect sensors and product the PWM signals having duty cycles proportional to the voltage drive requirements of the motor.Type: GrantFiled: September 28, 2016Date of Patent: November 20, 2018Assignee: MICROCHIP TECHNOLOGY INCORPORATEDInventors: Ward R. Brown, Howard Hendricks
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Patent number: 9692331Abstract: BLDC adaptive zero crossing detection compares BEMF voltages from a floating phase of a BLDC motor to a reference voltage, measures a rising time interval during a rising BEMF period when the BEMF voltages are greater than the reference voltage, and a falling time interval during a falling BEMF period when the BEMF voltages are less than the reference voltage. The reference voltage is adjusted so that the rising and falling time intervals are substantially the same, thereby causing the drive voltage to be in phase with the motor self-generated voltage, thus ensuring maximum efficiency of the BLDC motor.Type: GrantFiled: February 25, 2016Date of Patent: June 27, 2017Assignee: MICROCHIP TECHNOLOGIES INCORPORATEDInventor: Ward R. Brown
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Publication number: 20170093313Abstract: Low cost linear Hall Effect sensors are used for determining motor shaft positions and generating voltages proportional to the motor shaft positions. The voltages from the linear Hall Effect sensors are compared to a triangle waveform and PWM signals are generated therefrom. A constant current source and constant current sink are used in the triangle waveform generator. The voltages from the linear Hall Effect sensors are adjusted to change the PWM duty cycles used to startup and vary the speed of the motor. Comparators compare the voltages from the Hall Effect sensors and product the PWM signals having duty cycles proportional to the voltage drive requirements of the motor.Type: ApplicationFiled: September 28, 2016Publication date: March 30, 2017Applicant: Microchip Technology IncorporatedInventors: Ward R. Brown, Howard Hendricks
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Publication number: 20160254766Abstract: BLDC adaptive zero crossing detection compares BEMF voltages from a floating phase of a BLDC motor to a reference voltage, measures a rising time interval during a rising BEMF period when the BEMF voltages are greater than the reference voltage, and a falling time interval during a falling BEMF period when the BEMF voltages are less than the reference voltage. The reference voltage is adjusted so that the rising and falling time intervals are substantially the same, thereby causing the drive voltage to be in phase with the motor self-generated voltage, thus ensuring maximum efficiency of the BLDC motor.Type: ApplicationFiled: February 25, 2016Publication date: September 1, 2016Applicant: Microchip Technology IncorporatedInventor: Ward R. Brown
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Patent number: 9071172Abstract: A pulse width modulated (PWM) trapezoidal commutation drive to a brushless direct current (BLDC) motor is sine modified so that the applied drive voltage substantially matches the induced voltage generated in the BLDC motor. The values of the cosine of the angles between ?30 degrees and +30 degrees are used to modify the duty cycle of the PWM drive signal dependent upon the rotor angular positions determined from the times between the zero crossing BEMF voltages measured at the unconnected motor terminals.Type: GrantFiled: August 5, 2013Date of Patent: June 30, 2015Assignee: MICROCHIP TECHNOLOGY INCORPORATEDInventors: Ward R. Brown, Howard F. Hendricks
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Publication number: 20140265967Abstract: A pulse width modulated (PWM) trapezoidal commutation drive to a brushless direct current (BLDC) motor is sine modified so that the applied drive voltage substantially matches the induced voltage generated in the BLDC motor. The values of the cosine of the angles between ?30 degrees and +30 degrees are used to modify the duty cycle of the PWM drive signal dependent upon the rotor angular positions determined from the times between the zero crossing BEMF voltages measured at the unconnected motor terminals.Type: ApplicationFiled: August 5, 2013Publication date: September 18, 2014Inventors: Ward R. Brown, Howard Hendricks
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Patent number: 8803448Abstract: A constant current output sink or source eliminates a current limiting series resistor for a light emitting diode (LED) and maintains a constant light intensity from the LED for all operating and manufacturing variables of a digital device since the current through the LED is maintained at a constant value. The constant current output sink or source may be programmable for selection of a constant current value from a plurality of constant current values available.Type: GrantFiled: April 19, 2013Date of Patent: August 12, 2014Assignee: Microchip Technology IncorporatedInventors: Ward R. Brown, Randy Yach
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Publication number: 20130234623Abstract: A constant current output sink or source eliminates a current limiting series resistor for a light emitting diode (LED) and maintains a constant light intensity from the LED for all operating and manufacturing variables of a digital device since the current through the LED is maintained at a constant value. The constant current output sink or source may be programmable for selection of a constant current value from a plurality of constant current values available.Type: ApplicationFiled: April 19, 2013Publication date: September 12, 2013Applicant: Microchip Technology IncorporatedInventors: Ward R. Brown, Randy Yach
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Patent number: 8427075Abstract: A constant current output sink or source eliminates a current limiting series resistor for a light emitting diode (LED) and maintains a constant light intensity from the LED for all operating and manufacturing variables of a digital device since the current through the LED is maintained at a constant value. The constant current output sink or source may be programmable for selection of a constant current value from a plurality of constant current values available.Type: GrantFiled: November 20, 2009Date of Patent: April 23, 2013Assignee: Microchip Technology IncorporatedInventors: Ward R. Brown, Randy Yach
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Patent number: 8378606Abstract: Drive voltages to a sensorless brushless DC motor are regulated by varying the width of a single drive pulse (PWM pulse) centered in each of the commutation periods. Switching losses are thereby cut to an absolute minimum because there are only two transitions (on and off) in each drive commutation period. Back EMF zero-cross detectors determine the electrical timing relationships during each electrical cycle. Since the PWM drive pulses are always centered in each of the commutation periods, there will always be back EMF available for measurement of “zero-crossings.” A digital device controls power switching transistors to produce one single PWM pulse during each of the commutation periods.Type: GrantFiled: April 26, 2010Date of Patent: February 19, 2013Assignee: Microchip Technology IncorporatedInventor: Ward R. Brown
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Patent number: 8339077Abstract: Slow speed operation of a brushless DC (BLDC) motor is enhanced by gating off some of the PWM pulses in each commutation period. By doing so, longer PWM pulse widths may be used at PWM signal frequencies that are inaudible while still allowing desired slow speed operation of the BLDC motor. Centering the non-gated PWM pulses in each commutation period where peak back EMF occurs, further reduces losses and improves delivery of maximum torque from the BLDC motor.Type: GrantFiled: April 26, 2010Date of Patent: December 25, 2012Assignee: Microchip Technology IncorporatedInventor: Ward R. Brown
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Patent number: 8278860Abstract: Zero-crossing detection accuracy is enhanced in a sensorless brushless direct current (BLDC) motor by increasing the PWM drive frequency in anticipation of a zero-crossing event in any one or more commutation periods. Once a zero-crossing event is detected, the PWM frequency can go back to a lower normal operating frequency. Switching losses of the power drive transistors are thereby minimized while maintaining accurate zero-crossing detection for stable operation of the BLDC motor.Type: GrantFiled: April 26, 2010Date of Patent: October 2, 2012Assignee: Microchip Technology IncorporatedInventor: Ward R. Brown
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Publication number: 20110084639Abstract: Drive voltages to a sensorless brushless DC motor are regulated by varying the width of a single drive pulse (PWM pulse) centered in each of the commutation periods. Switching losses are thereby cut to an absolute minimum because there are only two transitions (on and off) in each drive commutation period. Back EMF zero-cross detectors determine the electrical timing relationships during each electrical cycle. Since the PWM drive pulses are always centered in each of the commutation periods, there will always be back EMF available for measurement of “zero-crossings.” A digital device controls power switching transistors to produce one single PWM pulse during each of the commutation periods.Type: ApplicationFiled: April 26, 2010Publication date: April 14, 2011Inventor: Ward R. Brown
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Publication number: 20110084635Abstract: Slow speed operation of a brushless DC (BLDC) motor is enhanced by gating off some of the PWM pulses in each commutation period. By doing so, longer PWM pulse widths may be used at PWM signal frequencies that are inaudible while still allowing desired slow speed operation of the BLDC motor. Centering the non-gated PWM pulses in each commutation period where peak back EMF occurs, further reduces losses and improves delivery of maximum torque from the BLDC motor.Type: ApplicationFiled: April 26, 2010Publication date: April 14, 2011Inventor: Ward R. Brown
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Publication number: 20110084640Abstract: Zero-crossing detection accuracy is enhanced in a sensorless brushless direct current (BLDC) motor by increasing the PWM drive frequency in anticipation of a zero-crossing event in any one or more commutation periods. Once a zero-crossing event is detected, the PWM frequency can go back to a lower normal operating frequency. Switching losses of the power drive transistors are thereby minimized while maintaining accurate zero-crossing detection for stable operation of the BLDC motor.Type: ApplicationFiled: April 26, 2010Publication date: April 14, 2011Inventor: Ward R. Brown
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Publication number: 20100148700Abstract: A constant current output sink or source eliminates a current limiting series resistor for a light emitting diode (LED) and maintains a constant light intensity from the LED for all operating and manufacturing variables of a digital device since the current through the LED is maintained at a constant value. The constant current output sink or source may be programmable for selection of a constant current value from a plurality of constant current values available.Type: ApplicationFiled: November 20, 2009Publication date: June 17, 2010Inventors: Ward R. Brown, Randy Yach