Stepping motor control circuit, movement, and analog electronic timepiece

Abstract

A stepping motor control circuit, a movement, and an analog electronic timepiece are disclosed. The invention aims to carry out precise rotation detection while reducing the influence of load change. A rotation detection circuit detects an induced current flowing through a drive coil of a stepping motor in a detection section divided into a plurality of sections (T1-T3), and detects a rotation state of the stepping motor on the basis of a pattern indicating whether or not the induced current exceeds a predetermined reference value in each of the sections (T1-T3). A control unit selects a drive pulse (P10-P1m, P2) corresponding to the rotation state detected by the rotation detection unit, and supplies a drive current to a drive coil to rotatably drive the stepping motor. The rotation detection unit carries out detection by selecting a detection direction of the induced current in the sections (T1-T3) after the first section (T1) on the basis of whether or not the induced current exceeding each of a plurality of reference values is detected plural times in the first section.

Description

technical field [0001] The invention relates to a stepping motor control circuit, a movement with the stepping motor control circuit and an analog electronic clock using the movement. Background technique [0002] Conventionally, stepping motors have been used in analog electronic clocks and the like. The stepping motors include: a stator having a through hole for accommodating a rotor and a plurality of positioning parts for determining a stable rest position of the rotor; The rotor in the bore; the drive coils wound on the above stator. In order to make the said stepping motor rotate more reliably, rotation detection is performed, and the drive according to the rotation detection result is performed (for example, refer patent documents 1-4). [0003] The rotation detection methods described in Patent Documents 1 and 2 are configured to have: a first detection interval for detecting the motion state of the rotor after the drive pulse is cut off; The second detection inter...

AI Technical Summary

Problems solved by technology

[0004] Although rotation detection is possible with this structure, there is a problem that when the load fluctuation (calendar load, load with a large needle moment) is large, the sensing signal fluctuates, making accurate rotation detection difficult.

As a result, there is a problem that the consumption current increases and the battery life decreases

[0007] In addition, the rotation detection method described in Patent Document 4 utilizes the fact that the detection timing of the induction signal is delayed as the load increases, and utilizes the pattern of the induction signal VRs in the section after the detection section is divided into a plurality of sections according to the step. However, as with the invention described in Patent Document 3, there is a problem that erroneous rotation detection may be performed due to the influence of load fluctuations and power consumption may increase.

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