| 摘要 |
PURPOSE:To prevent malfunction due to noise surely in any signal detecting circuit and to make switching operation stable, by providing a logic control circuit, a signal detecting circuit and a distributor with a signal switching and displaying device. CONSTITUTION:Distributors 3 and 19 are connected to an input terminal 1 of a signal switching and displaying device and to an input terminal 2 to which a different input signal from the terminal 1 is applied, and one of output sides of the distributors 3 and 19 is connected with contacts a and b of a relay 9. Another of the output side of the distributors 3 and 19 is connected with signal detecting circuits 7 and 11, a logic control circuit 13 is connected to the output side of the circuits 7 and 11, and display elements 14-18 are connected to the circuit 13. Further, to the output side of the circuit 7, a transistor 8 driving the relay 9 and a switching relay 12 switching and the of the circuit 13 are connected. Malfunction of the detecting circuits 7 and 11 is surely prevented against the input signal from the input terminals 1 and 2, allowing the device to be suited for video and audio switching and displaying device of an exclusive use TV or cable TV. |
