| 摘要 |
PURPOSE:To make a double compensation system operate without fail and to miniaturize an oscillator by using an AT plate crystal oscillator for a high- frequency oscillation circuit to raise a temperature at the inflection point of a cubic curve which indicates the temperature characteristic of a frequency. CONSTITUTION:The present timepiece is provided with a low-frequency oscillation circuit 1 having a compensation circuit 2 for compensating an output frequency, with a high-frequency oscillation circuit 6 generating a correction signal, with a comparison circuit 8 comparing a compensation signal with the correction signal, and with a temperature detecting unit 4 controlling the compensation circuit 2. The compensation of temperature by the circuit 1 is controlled by a detection signal of the unit 4, while the compensation of aged deterioration is controlled by a comparison output signal. In this case, the circuit 1 has an oscillator whose temperature characteristic of frequency is shown by a square curve, and the circuit 6 has an AT plate crystal oscillator whose temperature characteristic of frequency is shown by a cubic curve. The temperature of a zero temperature coefficient on the low-temperature side of the cubic curve is nearly in accord with the temperature of the zero temperature coefficient of the square curve. |
