| 摘要 |
PURPOSE:To reduce an energy consuption at a non-temperature measuring time and to enable placing of a thermometer in a small size information equipment such as wrist watches, by altering oscillation start voltage and oscillation stop voltage of two crystal oscillating circuits. CONSTITUTION:Oscillation start voltage and oscillation stop voltage of a crystal oscillator of a temperature sensor and an oscillating circuit 6 are higher than an output voltage of a low-voltage circuit 12 and lower than a voltage of a cell 13. If a switch 11 is connected to the low-voltage circuit side, a reference crystal oscillator and an oscillating circuit 1 oscillates, but the crystal oscillator of the temperature sensor and the oscillating circuit 6 do not oscillate, whereby no temperature is measured. When a temperature is measured, with the switch 11 connected to the cell 13 side, the crystal oscillator of the temperature sensor and the oscillating circuit 6 start oscillating to display a current temperature in a display unit 10. |
