| 摘要 |
PURPOSE:To simplify the constitution, by switching the illumination of an indicator with electronic control means. CONSTITUTION:When tuning is taken, a reception signal is outputted from a reception signal source 1, a reception signal detecting transistor (TR)3 is turned on and an output signal is applied to a Schmitt circuit 5. In the Schmitt circuit 5, when an input is absent or less, a TR7 turns on, a green diode 9 always illuminates and it acts like a dial pointer. When the reception signal level is more than the threshold voltage of the Schmitt circuit 5, a TR6 turns on and a TR7 switches to off-stage, allowing to illuminate a red light emitting diode 8 for the display of tuning. |
