| 摘要 |
PURPOSE:To dispense with setting of time by stopping of a clock function by stopping a display part when a solar battery does not generate electric power, and recording passing time while starting a counter. CONSTITUTION:When the outside is bright and a solar battery generates electric power sufficiently, hands of a display part 5 of a clock are driven by accuracy of a quartz oscillator. When the outside is dark and output voltage of the solar battery 1 becomes preset voltage or less, an illuminance judging circuit 4d stops output of a driving circuit 4b, and stops the hands of the display part 5, and starts a counter 4c simultaneously. Though electric power consumption of the display part 5 is generally large in a crystal clock, electric power consumption of an IC part 4 is small, so that the IC part 4 is hardly stopped. Afterwards, when the outside becomes bright and the output voltage of the solar battery 1 is increased, the illuminance judging circuit 4d rotates three motors at high speed so that the hands are put in positions corresponding to passing time of the counter 4c, and sends the three hands speedily. Thereby, setting of time can be carried out automatically. |
