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US 2012/0068649 A1Published application
Back-emf detection for motor control
AssigneeMarvell World Trade Ltd.
InventorsRavishanker KRISHNAMOORTHY, Foo Leng LEONG, Edy SUSANTO
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Abstract
Systems, methods, and other embodiments associated with back-EMF detection for motor control are described. In an embodiment, an apparatus includes a drive circuit configured to apply excitation signals to respective inputs of a motor, a signal inhibit circuit configured to convey a signal to inhibit application of the excitation signals during an interval, and a measuring circuit configured to measure a back-electromotive force (EMF) signal crossing a reference signal during the interval.
Claims19
An apparatus, comprising:
- a drive circuit configured to apply a plurality of excitation signals to respective inputs of a motor;
- a signal inhibit circuit configured to convey a signal to inhibit application of the plurality of excitation signals during an interval;
- and
- a measuring circuit configured to measure a back-electromotive force (EMF) signal crossing a reference signal during the interval.
1 more element
A method, comprising:
- inhibiting a plurality of excitation signals output to a motor;
- determining a time between the inhibiting of the plurality of excitation signals and a crossing of one of the plurality of excitation signals with a reference signal from the motor;
- modifying the plurality of excitation signals as a result of the determined time;
- and
- applying the modified plurality of excitation signals to the motor.
2 more elements
A device comprising:
- a circuit configured to couple a plurality of excitation signals to a motor;
- a measuring circuit configured to receive a reference signal;
- and
- logic configured to:
- inhibit the coupling of the plurality of excitation signals to the motor;
- measure a time at which a back-electromotive force from the motor drops below a level of the reference signal;
- and
- restart the coupling of the plurality of excitation signals to the motor.
5 more elements
Dependencies are inferred from the claim text.