| 摘要 |
PURPOSE:To make possible realization of the circuit of good longterm stability and less current consumption at good yield and low cost by using two crystal vibrators and series-connecting capacitors to one of the vibrators. CONSTITUTION:In a 2-crystal oscillation circuit, a built-in capacitor C'x and a variable capacitor Cx which are parallel connected are series-connected to one end of the crystal vibrator X2. When the capacities of the capacitors C'x and Cx are made small, oscillation frequency increases and when they are made large, the oscillation frequency decreases. Since the capacitors Cx,C'x are connected to the vibrator X2, the peak point frequency f2 of the vibrator X2 may be increased like dotted lines in the figure and may be matched to the peak point frequency f1 of the vibrator X1 by reducing the composite capacity of both, thus the oscillation circuit of flat frequency temperature characteristics may be obtained in a wide temperature range such as X1+X'2. Hence, the electronic watch of a wide frequency temperature compensation ragne, good long-term stability, less power consumption may be readily produced. |
