| 摘要 |
PURPOSE:To perform mode switching without providing any dedicated mode changeover switch by providing a control system which detects that a key for indicating frequency variation is pressed for a prescribed time or longer and performs switching from a manual mode to an automatic mode. CONSTITUTION:An indication signal generated by the key operation of an operation part 8 is supplied to an arithmetic circuit 17 through a decoder 12. The arithmetic circuit 17 monitors the operation time of the key, and when the key is pressed for the prescribed time or longer, the judgement of the state of the key is repeated without generating any stop signal C after one-step up or down operation. Then when the key operation is ceased, the monitoring of the operation time of the next key is started after the one-step up or down operation, and when no key is operated, the one-step up or down operation is restarted. When the signal C is confirmed, a decision on tuning is made and said operation is stopped to enter the automatic mode, but the arithmetic circuit 17 carries out said operation to control a programmable divider 19, performing tuning in corresponding modes. |
