US 2004/0195991 A1Published application

Step motor control device and electronic timepiece

AssigneeSeiko Instruments Inc.

InventorSaburo Manaka

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Abstract

To reduce power consumption without braking a step motor. In a given period after transistors are turned on and a motor is rotationally driven, the transistors are turned on, and the other transistors are turned off, and after the given period has elapsed, the on/off operation of the transistor is controlled at a given frequency in a state where the transistors are maintained in an on state, to thereby detect whether or not the motor rotates. Also, In a given period after the transistors are turned on and the motor is rotationally driven, the transistors are turned on and the other transistors are turned off, and after the above given period has elapsed, the on/off operation of the transistor is controlled at a given frequency in a state where the transistors are maintained in the on state, to thereby detect whether or not the motor rotates.

A step motor control device comprising:

first and second switch elements that are connected to each other in series;
third and fourth switch elements that are connected to each other in series;
a coil of a step motor which is connected between a connection point of the first and second switch elements and a connection point of the third and fourth switch elements;
a first series circuit including a fifth switch element connected in parallel with the first switch element and a first detection element;
a second series circuit including a sixth switch element connected in parallel with the third switch element and a second detection element;
a control means that controls the on/off operation of the first to fourth switch elements in response to a drive pulse to allow a current to flow in the coil to rotationally drive the step motor, and controls the on/off operation of the first, third, fifth and sixth switch elements in response to a rotation detection control pulse that is supplied immediately after the supply of the drive pulse is finished in a rotation detection period immediately after the rotation drive in accordance with the drive pulse;
and
a detecting means that detects the presence/absence of the rotation of the step motor on the basis of a comparison result of a voltage generated between the first and second detection elements and the coil with a given threshold voltage;
wherein the control means controls the on/off operation of the third switch element at a given frequency after a given period has elapsed in a state where the fourth and fifth switch elements are turned on, or controls the on/off operation of the first switch element at a given frequency after a given period has elapsed in a state where the third and sixth switch elements are turned on, and
the detecting means detects the presence/absence of the rotation of the step motor when the control means controls the on/off operation of the third switch element or the fourth switch element at a given frequency.

7 more elements

Facts

Application

10/784,382Filed 23 Feb 2004

Priority

JP 2003-04589624 Feb 2003

Published

7 Oct 2004

Term ends

Not estimatedThe source records don’t support an estimate.

Classification6 codes

H02P 8/34
Arrangements for controlling dynamo-electric motors rotating step by step: monitoring operation
G05B 19/40
Characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement…:…
G05B 2219/41326
Servomotor, servo controller till figures: step motor
G05B 2219/42198
Servomotor, servo controller kind till VSS: step motor driven by step size and step duration data

Abstract

Claims4