| 摘要 |
PROBLEM TO BE SOLVED: To maintain the output frequency of an oscillation circuit at a regulated value by providing the system with a circuit for allowing the output frequency of the oscillation circuit to follow reference frequency. SOLUTION: Any time when the frequency of a signal outputted from an oscillation circuit 10 to an input lead 30 exceeds the frequency of a reference signal supplied from a main timing circuit 24 to a phase comparator 26, a comparator 26 supplies relatively positive voltage to an output lead 32. When the positive signal is sent, a correction circuit 34 electrically add a capacitor between a node 12 and a reference potential point the ground. Any time when the frequency of a signal to the input lead 30 is lower than the frequency of the reference signal supplied from the circuit 24 to the comparator 26, relatively negative voltage is supplied to the output lead 32. When the negative signal is sent, the circuit 34 electrically removes a capacitor between the node 12 and the ground. |
