Stepping motor driver
AssigneePanasonic Corporation
InventorDaijiro Arisawa
Life of this patent
Estimating the term…
Abstract
In a drive of a stepping motor, an electromotive force is generated on the coil of a motor with a sinusoidal wave having the same period as an energization period by smoothly rotating a rotor with microstep driving, and an induced power is stably detected by detecting the electromotive force at the zero cross of driving current. The detection around the current zero cross makes it possible to shorten a detection section, form a driving waveform with few distortions, and perform driving with a driving waveform as in an ordinary micro step. Thus a circuit is provided which is aimed at reducing noise, vibrations, and loss of synchronization, and increasing current consumption efficiency in the determination of stop.
Claims5
1-16. (canceled)
A driver of a stepping motor, the driver comprising:
- an output unit for passing a load current to a driving coil of the stepping motor;
- a zero-cross detection unit for detecting a zero cross or near zero cross of the load current by comparing an input threshold with an input signal to the output unit which indicates an amount of the load current;
- an induced voltage detection unit for detecting an induced voltage of the driving coil when a zero cross or near zero cross of the load current is detected;
- and
- a determination unit for determining a state of a rotor of the stepping motor based on an induced voltage detected by the induced voltage detection unit.
Dependencies are inferred from the claim text.