| 摘要 |
PROBLEM TO BE SOLVED: To enable an electronic apparatus to detect and indicate such a state that is unlimitedly close to the actual service life state of a battery and, at the same time, to always display not only the service life of the battery, but also the remaining capacity of the battery while the circuit configuration of the equipment is simplified, when the apparatus uses the battery as a power source and an ultrasonic motor as a driving source. SOLUTION: In an electronic timepiece which uses an ultrasonic motor 30 as the driving source of a calendar displaying mechanism 42, a residual battery capacity displaying device is constituted of a residual battery capacity display 42, a number-of-revolution detector 43 which detects the number of revolutions of the motor 30, a memory 13 storing comparative data, and a CPU 11 which compares the number of revolutions of the motor 30 with the comparative data and drives the display 42 to display the residual capacity of a battery based on the compared results. An alarm 45 notifies the service life of the battery. |
