JPS6198017A - Signal switching device - Google Patents

Abstract

PURPOSE:To use a line which connects external equipment and a control amplifier together only for signals by providing a logic control circuit which controls a switch for electronic switching and a detecting circuit which detects an input signal. CONSTITUTION:An input signal to input terminals 9a-9c of the control amplifier 7 is detected by detecting circuits 16a-16c and if it is a control signal, the electronic switch 12 is switched by the logical circuit 10. The external equipment 1 is also provided with the detecting circuit 15 which detects the output signal of an output terminal 6; and the signal of the output terminal 6 is detected and the logical circuit 3 controls whether the control signal is outputted or not according to the detected state. The output terminal 6 is open if an electronic switch 12a is off when the switch SW2 is pressed, and that is detected by the detecting circuit 15 and detected by a detecting circuit 16a through a logical circuit 10 to turn on the electronic switch 12a.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a signal switching device in an audio or video system.

Conventional configuration and problems Generally speaking, an audio system consists of external equipment (tuner, cassette recorder, player, etc.) 1 as shown in Figure 1.
is connected to one of the input terminals 9a to 9C of the control amplifier 7, and the signal to be reproduced is selected by switching the signal selection switch 12. However, in order to reproduce the desired signal, the switch of the external device 1 must be 2 and the signal switch 11a of the control amplifier 7, which makes the operation complicated.

For this reason, conventionally, when the switch 2 of the external device 1 is pressed, the logic circuit 3 outputs a control signal as shown in FIG. 8, and the electronic switch 12 is switched through the logic circuit 1o by the control signal.

However, in this case, receiving and passing control signals always requires an additional connection line in addition to the one for signals, and the problem is that the more external devices there are, the more the number of connection lines increases and the wiring becomes complicated.

In FIG. 1, 4 is an amplifier for signal amplification of the external device 1, 6 is a signal output terminal, 9a to 9C are signal input terminals, 13 is an amplifier for signal amplification of the control amplifier 7,
14 is a signal output terminal 0 Purpose of the Invention The present invention 1 eliminates such conventional drawbacks, and provides a signal switching device that realizes signal selection with simple operation and a small number of connections. be.

Structure of the Invention The signal switching device of the present invention is a signal switching device equipped with at least two or more input terminals, and includes an electronic switching switch, a logic control circuit for controlling the switch, and a detection circuit for detecting an input signal. This device detects a control signal sent from an external device connected to an input terminal and controls an electronic switch for signal switching.

In this way, the connection line for connecting the external device and the control amplifier may be used only for signals, and the connection line for control is completely unnecessary.

DESCRIPTION OF EMBODIMENTS A signal switching device according to an embodiment of the present invention will be described below with reference to the drawings. In this embodiment, detection circuits 15a to 16c detect input signals of input terminals 9a to 9C of a control amplifier 7 shown in FIG. At the same time, the external device 1 is also provided with a detection circuit 15 that detects the output signal of the output terminal 6, and the logic circuit 3 controls whether the signal of the output terminal 6 is detected and whether or not a control signal is outputted depending on its state. This is what I did. By doing this, when the switch 2 of the external device 1 is pressed, the electronic switch 12a of the control amplifier 7
If it is off, the output terminal 6 of the external device 1 becomes open, so this is detected by the detection circuit 15, and the detection output is input to the fo-sick circuit 3, thereby outputting a control signal to the output terminal 6. Amplifier 7 controls that signal.
0 input terminal 9a, the detection circuit 16a detects the control signal, and the electronic switch 12 passes through the logic circuit 1o.
a can be turned on, thereby selecting the signal,
Can be played.

This situation is shown in FIG. 4. Effects of the Invention As described above, the signal switching device of the present invention does not require any control connection lines in addition to signal connection lines, and can simply operate external equipment. This makes it possible to reproduce the desired signal, eliminates the need for signal switching operations on the control amplifier, and is easy to connect since only the signal line is required.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a conventional signal switching device, FIG. 2 is a signal waveform diagram of the main part of FIG. 1, FIG. 3 is a block diagram of a signal switching device in an embodiment of the present invention, and FIG. 4 is the same. Signal waveform diagrams of main parts of the embodiment 01...external equipment, 2.
...Switch, 3...Logic circuit, 4.
...Amplifier, 5...Control signal output terminal,
6... Signal output terminal, 7... Control amplifier, 8a, 8b, 8c... Control input terminal. 9a, 9b, 9c...signal input terminals, 10...
...Logic circuit, 11a, 11b, 11c...
...Switch, 12a, 12b, 1'2cm electronic switch, 13...Amplifier, 14.Old...Output terminal, 15, 16a. 16b, 16c...Detection circuit.

Claims (1)

[Claims] External equipment configured to switch and output a control signal indicating the operation of an operation button and an information signal for reproduction to one output terminal, and a plurality of input terminals and switching between information signals from this input terminal. A control amplifier includes an electronic switch to be selected, a logic circuit for controlling the electronic switch, and a detection circuit for detecting a control signal from the input terminal, and an output terminal of the detection circuit is connected to the logic circuit. A control signal and an information signal output from an external device by operating the device are supplied to a common input terminal provided on the control amplifier, and the control signal is detected by the detection circuit of the control amplifier and sent to the logic circuit of the control amplifier. A signal switching device characterized in that the electronic switch is switched by the output of the logic circuit.