Stepping motor control circuit and analog electronic timepiece

Abstract

The invention relates to a stepping motor control circuit and an analog electronic timepiece capable of preventing the halfway stop by accurately determining the rotation status of a stepping motor even when the voltage of a secondary battery used as a power source is lowered. A detection interval in which the rotation status of a stepping motor is divided into a first interval immediately after driving executed by a main driving pulse, a second interval later than the first interval, and a third interval later than the second interval. The driving is executed by a correction driving pulse and the main driving pulse is increased, when a control circuit drives the stepping motor in a driving way different from a driving way at the time of exceeding a predetermined voltage in a case where the voltage of a secondary battery is lowered to be equal to or less than the predetermined voltage and when a rotation detection circuit and a detection time comparison determination circuit detect an induced signal exceeding a first reference threshold voltage in the first interval and the second interval and do not detect the induced signal exceeding a second reference threshold voltage lower than the first reference threshold voltage in the third interval.

Description

technical field [0001] The invention relates to a stepping motor control circuit and an analog electronic clock using the stepping motor control circuit. Background technique [0002] In the past, two-pole PM (Permanent Magnet: Permanent Magnet) type stepping motors were used in electronic equipment such as analog electronic clocks. This stepping motor has: a stator with a rotor housing hole and a positioning part that determines the stop position of the rotor; , which is arranged in the rotor housing hole; and a coil, which generates magnetic flux in the stator by providing an alternating signal to the coil, so that the rotor rotates, and stops the rotor in contact with the positioning part the corresponding location. [0003] As the low-consumption driving method of the two-pole PM type stepping motor, what has been practically applied is the correcting driving method of the stepping motor, which includes the main driving pulse P1 with small energy in general, and when th...

AI Technical Summary

Problems solved by technology

[0008] Before this standby state, the power supply voltage is low, so the drive is unstable, and the rotor may occasionally stop at an intermediate position different from the normal resting position of the rotor, that is, fall into a so-called intermediate stationary state, resulting in an erroneous determination of rotation or non-rotation problem, and there is a problem of needle movement delay

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