| 摘要 |
PROBLEM TO BE SOLVED: To improve the accuracy in timing by preventing it from being affected by the nonuniformity in the thermal variation characteristic of an oscillation frequency among quartz oscillators. SOLUTION: A measured temperature being the result of measurement of the ambient temperature of a quartz oscillator 3, sent from a temperature sensor 7, and a certain temperature set beforehand in a set temperature memory 11 are compared by a temperature comparing part 10. When the measured temperature is lower by a prescribed temperature or above than the certain temperature, power is supplied to an electric heater 8 and the power supply to the electric heater 8 is stopped at a time point when the measured temperature reaches the certain temperature, so that the ambient temperature of the quartz oscillator 3 be kept constant. According to this constitution, a change in the temperature of the quartz oscillator 3 itself is reduced, variation in the oscillation frequency of the oscillator is held down and the accuracy in timing is improved. |
