JPS6225307B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an intercom device in which a touch switch is provided within the handset.

BACKGROUND TECHNIQUES Conventionally used intercom devices all have a switch on the intercom body, and the handset side is simply a speaker,
It just contained a microphone.

Problems to be Solved by the Invention Therefore, in the above-mentioned conventional intercom device, all the circuits necessary for transmitting and receiving calls are housed in the intercom main body, and there are various restrictions on miniaturization of the intercom main body, and there are problems in terms of service. However, if the intercom itself is attached to a wall or the like, there is a problem in that it is very difficult to repair or inspect it.

Therefore, the inventor of the present invention first thought of providing a switch, a ringing tone generation circuit, etc. on the handset side, and making it smaller than the intercom itself. However, in this case, a separate dedicated transmission line is required to transmit the information when the hook switch is turned on, that is, the hook information, to the intercom main unit.
There is a problem in that the number of core wires of the handset cord that connects the handset and the intercom body increases accordingly.

The present invention eliminates the above-mentioned drawbacks of the conventional intercom, and provides an excellent intercom that can accurately transmit hook information from a switch installed in the handset to the intercom main body without increasing the number of core wires of the handset cord. The purpose is to provide a device.

Means for Solving the Problems In order to achieve the above object, the present invention provides a ringing signal line provided in the handset for transmitting a ringing signal from another station to a ringing tone generating circuit provided in the handset when a ringing signal arrives from another station. When the hook switch is turned on, a current flows in the opposite direction to the calling signal, thereby transmitting to the intercom main body that the hook switch is turned on.

Therefore, according to the present invention, the call signal line can be used as it is as a line for transmitting hook information, and hook information can be accurately transmitted from the handset side to the intercom body side without increasing the number of core wires of the handset cord. It has the effect that it can be transmitted to

Embodiment The figure is a wiring diagram of an embodiment of the intercom device of the present invention. In the figure, 1 is the interphone main body, 2 is a power supply terminal to which a predetermined positive voltage is applied, 3 is a calling signal terminal to which a calling signal from another station is applied, 4 is a connection terminal for a communication line, 5 is a ground terminal, 6 is a control circuit that turns on the subsequent transistor 7 when a calling signal from another station is applied to the calling signal terminal 3, 8 is a transistor that is turned on in the same way when transistor 7 is turned on, and 9 is connected in series with transistor 8. 10 is a diode for backflow prevention; 11 is a base; a transistor whose emitter is connected to the anode and cathode of diode 10; 12 is a hook information output terminal connected to the collector of transistor 11; 13 is a hook information output terminal connected to the collector of transistor 11; Resistors 21, 22, 23, and 24 connected in series with the transistor 8 together with the diode 9 are respectively connected to a power line in the handset cord, a calling signal line, a call signal line, and a ground line. The provided hook switch 32 is a diode connected between the hook switch 31 and the call signal line 22, 33 is a transistor that turns on when the hook switch 31 is turned on, and 34 is a predetermined signal applied to the call signal line 22 from the intercom main body 1 side. 35 is a call signal line 23 which outputs a ring tone when the call is made.
36 is an amplifier for receiving calls, 37 is a speaker, 38 is an amplifier for sending calls, and 39 is a microphone for sending calls.

Next, the operation of the above embodiment will be explained.
Assume that a call signal is applied to the call signal terminal 3 of the intercom main body 1 from another station while the intercom is in a standby state, that is, the switch 31 is off. When a calling signal is applied to the calling signal terminal 3, the control circuit 6 is driven thereby, and the transistors 7 and 8 are turned on. When the transistor 8 is turned on, a predetermined current flows through the transistor 8, the diode 9, and the resistor 13, and a predetermined voltage appearing across the resistor 13 is applied to the handset 3 via the diode 10 and the call signal line 22.
It is applied to the ringing tone generation circuit 34 in 0. When the predetermined voltage is applied to the ringing tone generation circuit 34,
The ringing tone generation circuit 34 is thereby triggered and outputs a predetermined ringing tone. Then, the ringing tone is amplified by the amplifier 36, applied to the speaker 37, and emitted from the speaker 37.

Upon hearing the ringing tone from the speaker 37, the user lifts up the handset and turns on the switch 31, thereby turning on the transistor 33, and the input end of the ringing tone generation circuit 4 is grounded through the transistor 33. Therefore, in this state, the operation of the ringing tone generation circuit 4 is stopped and generation of the ringing tone is stopped. Then, when the switch 31 is turned on,
At the same time, a positive voltage from the power supply line 21 is applied to the handset code call signal line 22 via the hook switch 31 and the diode 32, which turns on the transistor 11 and outputs a predetermined signal to the hook information output terminal 12. A voltage appears. That is,
When the switch 31 is off, a diode 9 and a resistor 13 are connected to the base of the transistor 11.
Only the voltage appearing at the connection point of the transistor 11 is applied, and in this state, the voltage applied to the base of the transistor 11 is higher than the voltage applied to the base of the diode 11.
A voltage lower by the voltage drop due to zero is applied, and the transistor 11 is not turned on. However, when the switch 31 is turned on, a voltage is applied to the emitter of the transistor 11 through the diode 32 and the call signal line 22. A voltage higher than the voltage applied to the base is applied, turning on the transistor 11, and information that the hook switch 31 has been turned on, that is, hook information, is output to the hook information output terminal 12. Therefore, by using this information, a special circuit such as a confidential communication circuit can be easily installed as an option on the intercom main body side, and the functions and uses can be expanded.
In addition, lift the handset and switch the hook switch 31.
When the ring tone generating circuit 34 is turned on, the ring tone generating circuit 34 is inactive due to the action of the transistor 33, so the call signal from the other station is transmitted from the connection terminal 4 of the call line to the call signal line 23, the hybrid circuit 35, and the call signal from the other station.
The call signal is applied to the speaker 37 via the amplifier 36, and the call signal from the microphone 39 is transmitted to another station via the amplifier 38, the hybrid circuit 35, the call signal line 23, and the call line connection terminal 4.
You will be able to freely communicate in both directions.

Effects of the Invention As is clear from the above embodiments, the present invention provides a hook switch on the handset side, and when the hook switch is turned on, a predetermined current is applied to the call signal line in the handset cord in the opposite direction to the signal at the time of a call. This system is configured so that the intercom body side detects it and outputs the hook information on the intercom body side, and the intercom body side can connect the hook of the hook switch installed on the handset side without increasing the number of core wires of the handset cord. This has the advantage that it is possible to obtain an excellent intercom device that is capable of detecting information, is small overall, and has good serviceability.

[Brief explanation of the drawing]

The figure is a wiring diagram of one embodiment of the intercom device of the present invention. 1... Intercom body, 6... Control circuit,
7, 8, 11, 23...transistor, 9, 1
0, 32...Diode, 30...Handset, 31...Hook switch, 34...Ring tone generation circuit, 35...Hybrid circuit, 36, 38
...Amplifier, 37...Speaker, 39...Mic.

Claims (1)

[Claims] 1 When a ringing signal arrives at the intercom body from another station, in response, a predetermined signal is transmitted to the ringing tone generation circuit provided in the handset via the ringing signal line in the handset cord, and the ringing tone is generated. In addition to providing means for driving the generating circuit, the handset is provided with a hook switch, and the handset is provided with means for stopping the driving of the ring tone generating circuit when the hook switch is turned on. An intercom device in which a current in a direction opposite to the above-mentioned predetermined signal is passed through a calling signal line and a means for detecting the current is provided in each handset body.