Title:
CONTROLLER FOR MOVABLE MEMBER
Document Type and Number:
Japanese Patent JPH03135396
Kind Code:
A
Abstract:
PURPOSE: To drive an electric motor with a simple method by controlling a circuit for controlling the supply of power to the electric motor with a sensor that responds to the phase difference between the current of the stator coil winding of the electric motor and the voltage between coil windings. CONSTITUTION: A sensor 32 has a comparator 33 and receives a signal SI and a signal SII by the comparator 33. The signal SI indicates current in the stator coil winding of an electric motor 22 and the zero point passage of the current, and the signal SII indicates the zero point passage of a voltage between coil windings. For creating the signal SI, the sensor 32 has a device 34 for measuring the coil winding current of the electric motor 22 and a device 35 for detecting the zero point passage of the current in series. For creating the signal SII, the sensor 32 has a device 36 for constituting an interface between an AC-line voltage and a low-voltage control unit 24 in series, a device 37 for detecting the zero point of the voltage, and a device 38 for generating a pulse during a specified period starting from the time when the voltage passes the zero point.
Inventors:
FUIRITSUPU KURARA
Application Number:
JP26030790A
Publication Date:
June 10, 1991
Filing Date:
September 28, 1990
Export Citation:
Assignee:
ESSILOR INT
International Classes:
G02C13/00; B24B9/14; B24B13/005; G05D3/12; H02P23/00; (IPC1-7): B24B9/14; B24B13/005; G02C13/00; H02P7/36
Attorney, Agent or Firm:
Minoru Nakamura (7 outside)