Peak current regulation for stepper motors
AssigneeTexas Instruments Incorporated
InventorsVenkata Naresh Kotikelapudi, Ganapathi Shankar Krishnamurthy, Laxman Sreekumar, Siddhartha Gopal Krishna
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Abstract
A method for controlling a stepper motor includes calculating a duty cycle of a current provided to the stepper motor and comparing a difference, between the calculated duty cycle and a base duty cycle of current provided to the stepper motor under a base load condition, to a reference duty cycle value. The method also includes adjusting a peak current level of the current provided to the stepper motor responsive to the comparison.
Claims20
A method for controlling a stepper motor, the method comprising:
- calculating a duty cycle of a current provided to the stepper motor;
- comparing a difference between the calculated duty cycle and a base duty cycle of current provided to the stepper motor under a base load condition, to a reference duty cycle value;
- and
- adjusting a peak current level of the current provided to the stepper motor responsive to the comparison.
A device adapted to be coupled to a stepper motor and operable to control the stepper motor, the device comprising:
- a processing device having a first output adapted to be coupled to the stepper motor and a second output, the processing device configured to:
- calculate a duty cycle of a current provided to a stepper motor;
- and
- output, at the second output, a calculated duty cycle signal indicative of the calculation;
- at least one register coupled to the processing device and configured to store a base duty cycle value of current provided to the stepper motor under a base load condition, and to store a reference duty cycle value;
- a subtractor coupled to the processing device and to the at least one register, the subtractor configured to:
- receive the calculated duty cycle signal;
- and
- provide a subtractor signal responsive to a difference between the calculated duty cycle and the base duty cycle value;
- and
- an error amplifier coupled to the subtractor and to the at least one register, the error amplifier configured to:
- receive the subtractor signal;
- compare the subtractor signal to the reference duty cycle value;
- and
- provide an error signal responsive to the comparison;
- wherein the processing device is further configured to adjust a peak current level of the current provided to the stepper motor responsive to the error signal.
A system adapted to be coupled to a stepper motor and operable to control the stepper motor, the system comprising:
- a driver coupled to the stepper motor, the driver configured to control a voltage applied to the stepper motor;
- and
- a controller coupled to the driver, the controller configured to:
- calculate a duty cycle of a current provided to the stepper motor;
- compare a difference between the calculated duty cycle and a base duty cycle of current provided to the stepper motor under a base load condition, to a reference duty cycle value;
- and
- adjust a peak current level of the current provided to the stepper motor responsive to the comparison.
Dependencies are inferred from the claim text.