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US 8,482,241 B2Granted
System and method for using a stepper motor as a rotary sensor
AssigneeCypress Semiconductor Corporation
InventorRakesh Reddy
Life of this patent
Estimating the term…
Abstract
A method and apparatus for driving a stepper motor and using the stepper motor as a rotary sensor when the stepper motor is not being driven.
Claims20
A method, comprising:
- determining whether a control signal is provided by a control circuit;
- if the control signal is not provided, measuring, by the control circuit, a change in voltage across a first stepper motor coil and across a second stepper motor coil, the change in voltage resulting from movement of a rotor;
- and
- determining a rotation of the rotor from the change in voltage.
1 more element
An apparatus, comprising:
- a stepper motor comprising a first stepper motor coil, a second stepper motor coil and a rotor;
- a control circuit coupled to the stepper motor;
- and
- a stepper motor circuit coupled to the control circuit and to the stepper motor, the stepper motor circuit to determine whether a control signal is provided by the control circuit, and if the control signal is not provided, the control circuit to measure a change in voltage across the first stepper motor coil and across the second stepper motor coil, the change in voltage resulting from movement of the rotor, and determine a rotation of the rotor from the change in voltage.
1 more element
An apparatus, comprising:
- a stepper motor comprising a first stepper motor coil, a second stepper motor coil and a rotor;
- a stepper motor circuit coupled to the stepper motor, the stepper motor circuit comprising:
- a first stepper motor drive circuit to drive the first stepper motor coil,
- a second stepper motor drive circuit to drive the second stepper motor coil, and
- a switch to supply power to the first and second stepper motor drive circuits if a control signal is provided by a control circuit and to disconnect power from the first and second stepper motor drive circuits if the control signal is not provided by the control circuit;
- the control circuit coupled to the stepper motor circuit, if power is disconnected from the first and second stepper motor drive circuits, the control circuit to measure a change in voltage across the first stepper motor coil and across the second stepper motor coil, the change in voltage resulting from movement of the rotor, and determine a rotation of the rotor from the change in voltage.
3 more elements
Dependencies are inferred from the claim text.