Three-phase brushless motor state identification
First Claim
1. A system for determining a state of a motor, comprising:
- a motor driving circuit operable to couple to and drive the motor associated with first, second and third phases;
a control circuit coupled to the motor driving circuit;
a first bias circuit coupled at a first input to a first node and coupled at a second input to the control circuit;
a second bias circuit coupled at a first input to the first node and coupled at a second input to the control circuit;
a first comparator coupled at a first input to a second node and coupled at a second input to an output of the first bias circuit; and
a second comparator coupled at a first input to the second node and coupled at a second input to an output of the second bias circuit.
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0 Petitions
Accused Products
Abstract
A method for determining the state of a brushless motor having first, second and third phases, in some embodiments, comprises: decoupling said motor from a power source; determining whether said motor is rotating or non-rotating; if the motor is rotating, determining a first phase voltage state relative to a common voltage and a second phase voltage state relative to the common voltage, said first phase and second phase voltage states determined when a third phase voltage is within a predetermined range of said common voltage; and if the first phase voltage state and the second phase voltage state are the same, repeating said determination as to whether the motor is rotating or non-rotating.
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Citations
20 Claims
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1. A system for determining a state of a motor, comprising:
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a motor driving circuit operable to couple to and drive the motor associated with first, second and third phases; a control circuit coupled to the motor driving circuit; a first bias circuit coupled at a first input to a first node and coupled at a second input to the control circuit; a second bias circuit coupled at a first input to the first node and coupled at a second input to the control circuit; a first comparator coupled at a first input to a second node and coupled at a second input to an output of the first bias circuit; and a second comparator coupled at a first input to the second node and coupled at a second input to an output of the second bias circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for determining a state of a motor, comprising:
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a first comparator; a second comparator; and a control circuit coupled to the first comparator and the second comparator and operable to; determine that the motor is rotating when an output of the first comparator and an output of the second comparator are both positive or are both negative; determine a voltage of a first phase of the motor relative to a common voltage present at a common node of the motor when the motor is rotating and a voltage of a third phase of the motor is approximately equal to the common voltage; and determine a voltage of a second phase of the motor relative to the common voltage present at the common node when the motor is rotating and a voltage of the third phase of the motor is approximately equal to the common voltage. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. A system, comprising:
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a motor driving circuit operable to couple to and drive a motor associated with first, second and third phases; a control circuit coupled to and operable to control the motor driving circuit; a first comparator operable to; receive a first biased version of a common voltage at one input and a first phase voltage, a second phase voltage, or a third phase voltage at another input; and provide an output of the first comparator to the control circuit; and a second comparator operable to; receive a second biased version of the common voltage at one input and the first phase voltage, the second phase voltage, or the third phase voltage at another input; and provide an output of the second comparator to the control circuit, wherein, the control circuit is further operable to; determine that the motor is rotating when the outputs of the first and second comparators are both positive or are both negative; determine a first phase voltage state relative to the common voltage when the motor is rotating and a third phase voltage is approximately equal to the common voltage; and determine a second phase voltage state relative to the common voltage when the motor is rotating and the third phase voltage is approximately equal to the common voltage. - View Dependent Claims (19, 20)
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Specification