Driver circuit
AssigneesSemiconductor Components Industries, LLC, Sanyo Semiconductor Co., Ltd.
InventorKosaku Hioki
Life of this patent
Estimating the term…
Abstract
A stepping motor includes two coils. A driver circuit drives the stepping motor by setting dissimilar phases of supply currents to these two coils. One terminal of one coil is connected to ground and another terminal is set to a high impedance state, and an induced voltage generated at that coil is detected as a voltage with respect to ground. Then, in accordance with the state of the detected induced voltage, the magnitude of motor drive current supplied to the two coils is controlled.
Claims10
A driver circuit for a stepping motor, the stepping motor comprising two coils supplied with drive voltages having different phases and configured to rotate a rotor driven by the coils,
- the driving circuit comprising:
- a detector configured to detect an induced voltage generated at one of the two coils while one terminal of the one of the two coils is connected to a constant voltage and another terminal of the one of the two coils is set to high impedance, the induced voltage being detected at the another terminal;
- and
- a controller configured to control a magnitude of the drive voltages supplied to the two coils in accordance with a state of the detected induced voltage.
A driver circuit for a stepping motor, the stepping motor comprising two coils supplied with drive voltages having different phases and configured to rotate a rotor driven by the coils,
- the driving circuit comprising:
- a detector configured to detect a waveform of an induced voltage generated in a phase of one of the two coils where a drive voltage for the one of the two coils becomes 0;
- and
- a controller configured to determine a suitability of motor drive currents in accordance with a type of detected waveform, and to control a magnitude of the motor drive currents supplied to the two coils in accordance with the detected waveform.
A driver circuit for a stepping motor, the stepping motor comprising two coils supplied with drive voltages having different phases and configured to rotate a rotor driven by the coils,
- the driving circuit comprising:
- a detector configured to detect a slope of an induced voltage generated in one of the two coils in a phase where a drive voltage for the one of the two coils becomes 0 is detected;
- and
- a controller configured to estimate a zero cross point of a induced voltage waveform from the detected slope, and to control a magnitude of motor drive currents supplied to the two coils in accordance with the phase of the estimated zero cross point.
Dependencies are inferred from the claim text.