Patent ID: 11906934
Assignee: SEIKO EPSON CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A watch motor control circuit comprising:
a driver configured to be controlled to be in an ON state in which a drive current is supplied to a coil of a watch motor, and an OFF state in which the drive current is not supplied;
a current detector including a lower limit detector configured to detect that the drive current flowing through the coil is less than a lower limit current value, and an upper limit detector configured to detect that the drive current flowing through the coil is greater than an upper limit current value;
a driver controller that, after controlling the driver to be in the ON state, is configured to control the driver to be in the OFF state when the upper limit detector detects that the drive current is greater than the upper limit current value, and, after controlling the driver to be in the OFF state, is configured to control the driver to be in the ON state when the lower limit detector detects that the driver current is less than the lower limit current value;
a polarity switching controller configured to alternately switch a polarity of the drive current to a first polarity or a second polarity when an ON time period that is a duration of the ON state of the driver, or an OFF time period that is duration of the OFF state of the driver meets a polarity switching condition;
a sampling controller configured to, at a sampling cycle, intermittently cause the current detector and the driver controller to operate; and
a sampling cycle setting controller configured to detect a sampling cycle setting condition and change the sampling cycle in at least two stages of a first cycle and a second cycle longer than the first cycle, in accordance with the detected sampling cycle setting condition.