JPH0252915B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a private branch exchange device used as a communication system in places with relatively large premises, such as factories, schools, hospitals, and company offices.

Configuration of a conventional example and its problems FIG. 1 shows an example of a conventional private branch exchange device. The configuration of this conventional example will be explained below with reference to FIG. 1.

In FIG. 1, 1 indicates a part of the main device of a private branch exchange, and 2 indicates a telephone set. Inside the main device 1, 3 is a relay for transmitting an incoming signal, 4 is an oscillator thereof, 5 is a photocoupler for DC loop detection, 6 is a DC supply circuit, 7 is a DC cut capacitor, 8
9 is a coupling transformer, 9 is a link switch for forming a communication path, and 10 is a control circuit for controlling the link switch 9 based on a signal from the photocoupler 5. Inside the telephone 2, 11 is a ringer circuit that operates in response to an incoming signal and generates a ringtone, 12 is a DC cut capacitor, 13 is a hook switch, 14 is a di relay for sending out dial signals, and 15 is a call circuit. A DC loop is also formed in the system circuit. 16 is a receiver, and 17 is a transmitter.

Next, the operation of this conventional example will be explained. 1st
In the figure, when telephone 2 receives a call from another telephone, relay 3 operates in main device 1, and an incoming signal, for example, a 16Hz periodic ringer signal, is sent from oscillator 4 through relay 3 to telephone 2. sent to. In the telephone 2, the signal is transmitted to the ringer circuit 11 through the capacitor 12, and a ringing tone is output. When the telephone 2 is turned off in this state, the switch (HS) 13 is closed and a DC loop is formed by the communication circuit 15. The ringer signal is periodic and relay 3 also operates periodically, e.g. ON for 1 second, ON for 3 seconds.
Since the relay is OFF, the photocoupler 5 detects the DC loop and transmits it to the control circuit 10 when the relay is OFF. At this time, the DC current flows through a route from the (+) terminal of the DC supply circuit 6 to the relay 3, the switch 13, the di relay 14, the communication circuit 15, the relay 3, the photocoupler 5, and the (-) terminal of the DC supply circuit 6. flows. Now, the control circuit 10 turns on the link switch 9 for forming a communication path, and connects the coupling transformer 8, capacitor 7, relay 3, hook switch 13, di relay 14, communication circuit 15, receiver 16, and transmitter 17 to the communication path. is formed.

By the way, in the case of this conventional example, the incoming signal is applied directly to the ringer circuit 11 from the oscillator 4 via the relay 3 and the capacitor 12, and a relatively high level is required as the incoming signal. Furthermore, since the ringer circuit 11 is directly connected in parallel to the speech circuit 15 via the capacitor 12, there is a problem in that the speech signal is greatly attenuated in the ringer circuit 11 during speech communication, resulting in a reduction in speech quality.

Next, FIG. 2 shows a conventional private branch exchange system having another configuration. The configuration of this conventional example will be explained below with reference to FIG.

In FIG. 2, 18 is a part of the main device, and 19 is a telephone. Inside the main device 18, 20
is a call coupling transformer, 21 is an incoming signal generation circuit,
22 is a link switch for transmitting an incoming call signal, 23 is a link switch for forming a communication path, 24 is a control circuit for controlling these link switches and transmitting and receiving control signals to and from the telephone set, 25 and 26 are capacitors for cutting DC, 27 is a DC supply circuit. Also, inside the telephone 19, 28, 29, and 30 operate simultaneously as a switch. 31 is a communication circuit, 32 is a receiver, 33 is a transmitter, 34 is an amplifier for amplifying an incoming signal, and 35 is a speaker for producing a ring tone. 36 is a dial detection circuit, 37 is a telephone control circuit that sends out switch information and dial information to the main device, 38 and 39 are DC cut capacitors, and 40 is a DC current extraction circuit.

In FIG. 2, when telephone 19 receives a call from another telephone, control circuit 24
turns on the link switch 22, and an incoming signal, for example, a 400 Hz signal, is sent from the incoming signal generation circuit 21 to the telephone 19 through the link switch 22 and the coupling transformer 20. In the telephone 19, the signal is amplified by an amplifier 34 through a switch 29, and a ringtone is output from a speaker 35. In addition, in the case of a voice call, the control circuit 24 turns on the link switch 23.
The voice signal from the caller is transmitted to the link switch 23, coupling transformer 20, hook switch 29,
The sound is amplified by 34 amplifiers and output as sound from 35 speakers. From this state, phone 19
However, when the switch is turned OFF, the switch 28 closes and the switch 29 opens. Also, the hook switch 30 is closed and the telephone control circuit 37 transmits the hook information to the control circuit 24 of the main unit 18. During signal calling, the control circuit 24 turns off the link switch 22 and turns on the link switch 23 to form a communication path. As a result, the call path is
Link switch 23, transformer 20, hook switch 28, telephone circuit 31, receiver 32, transmitter 3
It is formed by three routes.

In the case of this conventional example, a separate incoming signal generator 21 is provided, and the output thereof is amplified by an amplifier 34 provided on the telephone 19 side and applied to a speaker 35. There is no need to use high-level products as in the conventional example shown.
Furthermore, a switch 29 is provided on the input side of the amplifier 34 to turn it off during a call, and there is an advantage that the incoming call circuit section comprising the amplifier 34, speaker 35, etc. does not attenuate the call signal during a call.

However, in the case of this conventional example, the on/off state of the switch switches 28, 29, 30 is detected by the telephone control circuit 37 provided within the telephone 19, and the control circuit within the main unit 18 is detected via a separately provided control signal path. Since the signal is configured to be transmitted to the circuit 24, there is a problem in that a communication signal path and a control signal path are respectively required as signal paths.

Purpose of the Invention The present invention eliminates the above-mentioned drawbacks of the conventional technology, and has two wires for wiring between the main device and each telephone, and furthermore, the incoming circuit section does not have any influence on the calling circuit section. The purpose is to provide an excellent private branch exchange system that is not available in the market.

Structure of the Invention In order to achieve the above-mentioned object, the present invention reverses the polarity of the supply voltage supplied from the main device to the telephone during standby and during talking, so that the above-mentioned telephone is supplied only with each polarity. The above-mentioned supply voltage is applied to the calling circuit section and the receiving circuit section respectively provided in the telephone call circuit section and the receiving circuit section, respectively, and the telephone calling circuit section and the receiving circuit section are respectively provided with a switch that operates in different states from each other. The OFF state is detected by turning on and off the supply voltage supplied to the calling circuit section and the receiving circuit section through the switch.

DESCRIPTION OF EMBODIMENTS The configuration of an embodiment of the present invention will be described below with reference to the drawings.

In FIG. 3, numeral 41 is a part of the main device for exchanging calls, and 42 and 43 are respective telephones connected to the main device by two lines. Inside the main device 41, 44 is the telephone 4.
The A relay reverses the polarity of the voltage supplied to the terminal 2, and a ₁ and a ₂ are its contacts. 45 is a transistor for relay operation, 46 is a photocoupler for DC loop detection, 47 is a DC supply circuit, 48 is a DC cut capacitor, 49 is a coupling transformer for communication signals and incoming signals, 50 is an incoming signal generation circuit, 51 52 is a link switch that opens and closes the signal to telephone 42, 53 is a link switch that forms a communication path between telephones 42 and 43, and 54 is a link switch for these links. The controlling link switch control section 55 is a loop signal receiving section that operates with an input signal from the photocoupler 46 and transmits a signal to the link switch control section 54 and operates the relay transistor 45. Below is a similar circuit for the telephone 43, 56 is a coupling transformer, 57 is a capacitor, 58 is a DC supply circuit, 59 is a loop signal receiver, 60 is a photocoupler, 61 is a transistor, 62 is a B relay, b ₁ , b ₂ is the contact point. Inside the telephone 42, 63, 64, 6
5 and 66 are diodes that regulate the direction of direct current, 67 is a yoke for cutting off an alternating current signal, 68 is a capacitor for cutting off direct current, and 69 and 72 are switch switches (HS) that are in the state shown in the figure during standby.
70 is an amplifier that amplifies the incoming signal, 71 is a speaker that converts the incoming signal into a ring tone and outputs it, 73 is a di relay contact that opens and closes when dialing, 74 is a communication circuit, 75 is a receiver, and 76 is a transmitter. The telephone set 43 also has a similar configuration.

Next, the operation of this embodiment will be explained.

Now, if telephone 42 receives a call from telephone 43, link switch control section 54 closes link switch 51. As a result, the incoming signal is transmitted from the generation circuit 50 to the link switch 51, the coupling transformer 49, the capacitor 48, and the A relay contacts _a1 , _a2.
It is sent to the telephone 42 through. At this time, the DC current flows from the (+) terminal of the supply circuit 47 through the A relay contact a ₂ , the diode 66, the chain yoke 67, and the switch 69, and becomes the power source for the amplifier 70.
Diode 64, A relay contact _a1 , photocoupler 4
6 to the (-) terminal of the DC supply circuit 47. Therefore, during standby, diode 6
6 and 64 are ON, the incoming signal passes through the capacitor 68, is amplified by the amplifier 70, and is output as a ring tone from the speaker 71. In this state, when the telephone 42 picks up the call (OFF HooK), the hook switch 69 opens and the hook switch 72 closes. Therefore, the DC loop that has been flowing until now is opened, and the photocoupler 46 notifies the loop signal receiving section 55 that the loop has opened, turning on the transistor 45. As a result, A relay 4
4 works, contacts a ₁ and a ₂ fall to the make side, and the polarity is reversed. At this time, direct current flows from the (+) terminal of the direct current supply circuit 47 to the contact a ₁ , the diode 63, and the HS7
2, di relay 73, call circuit 74, diode 6
5, contact _a2 , photocoupler 46, DC supply circuit 47
The current flows through the (-) terminal path. Further, the loop signal receiving section 55 transmits a signal to the link switch control section 54, and the link switch control section 54 opens the link switch 51 and closes the link switch 53. Therefore, a communication path is formed between the telephone set 43 and the telephone set 42, and the voice signal from the telephone set 43 is passed through the relay contact.
b ₁ , b ₂ , capacitor 57, transformer 56, link switch 53, transformer 49, capacitor 48,
transmitted to the telephone 42 through relay contacts _a1 and _a2 ,
Hook switch 72, di relay 73, call circuit 7
4, and the voice is output from the receiver 75. In the case of transmission, the signal enters from the transmitter 76 and is transmitted to the telephone set 43 through the same route in reverse. Now, from the call state,
When the handset of the telephone 42 is placed (ON HooK), the switch 72 opens and the communication current stops flowing, which is detected by the photocoupler 46, and the loop signal receiver 55 turns off the relay transistor 45.
At the same time, a signal is transmitted to the link switch control section 54, and the link switch control section 54 opens the link switch 53. The A relay 44 enters the break state, and the contacts a ₁ and a ₂ return to the standby state and the polarity is reversed again. In the telephone 42, since the switch 69 is closed, the current during standby flows through the amplifier 70 again, returning to the initial standby state. FIG. 4 shows the movement of the line current due to the above series of operations. When a ringtone is output, more current flows than during standby. Further, FIG. 5 shows the flow of the series of operations separately for the main device and the telephone.

This embodiment has the advantage of being able to amplify and output the signal from the main device as it is by applying a voltage opposite to that during a call during standby and activating the amplifier on the telephone side during standby. In addition, since the system operates only at the voltage opposite to that during standby during a call, there is an advantage that the main unit can reliably detect the telephone's hook.

Effects of the Invention As is clear from the above description, the present invention reverses the polarity of the supply voltage supplied from the main device to the telephone during standby and during talking, so that the voltage is supplied to the telephone only in each polarity. The above-mentioned supply voltage is applied to the telephone call circuit section and the call receiving circuit section, respectively, and the telephone call circuit section and the call receiving circuit section are each provided with a switch that operates in a different state from each other, and these switch switches are turned on and off. is configured to be detected by turning on and off the supply voltage supplied to the calling circuit section and the receiving circuit section through the box switch, and is detected depending on the polarity of the supply voltage supplied from the main device. Since the supply voltage is selectively applied to the call circuit section and the call receiving circuit section, the supply voltage is never applied to these circuit sections at the same time, and when making a call, the call receiving circuit section is connected to the call circuit section. It has the advantage of having almost no negative impact on the body. According to the present invention,
Since the configuration is such that the on/off state of the box switch is detected by the on/off state of the supply voltage supplied to the calling circuit section and the receiving circuit section through the box switch, a separate detection means is required to detect this. There is no need to provide any wires in the telephone, and therefore two wires are sufficient for connecting the main device and each telephone, which has the advantage of making the wiring considerably easier.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a conventional two-wire private branch exchange device, FIG. 2 is a configuration diagram of a four-wire conventional private branch exchange device, and FIG. 3 is a configuration diagram of a private branch exchange device in an embodiment of the present invention. 4 is a diagram showing the movement of the line current during the operation, and FIG. 5 is a flowchart of the basic operation. 47, 58... DC current supply circuit, 50... Incoming signal generation circuit (TONE), 54... Link switch control circuit, 55, 59... Loop signal receiving section, 74... Call circuit.

Claims (1)

[Claims] 1 Consisting of a main device and a telephone, the main device includes an incoming call detecting means for detecting an incoming call, a DC supply circuit for obtaining a supply voltage to the telephone, and the incoming call detecting means detecting the incoming call. an incoming signal link switch means for superimposing an incoming signal from a separately provided incoming signal generating circuit on the supply voltage supplied to the telephone from the DC supply circuit and transmitting the superimposed signal to the telephone; when the telephone goes off-hook; Means for detecting this and turning off the incoming signal link switch means to stop sending out the incoming signal from the incoming signal generating circuit; A telephone link switch means for superimposing a telephone signal on the supply voltage to enable the transmission of a telephone call signal, and when detecting the off-hook of the telephone set, the polarity of the supply voltage supplied to the telephone set from the DC supply circuit is determined. The telephone is provided with a polarity reversing means for reversing the polarity, and the telephone has an incoming call circuit section that operates with the supply voltage supplied from the DC supply circuit when the polarity of the supply voltage supplied from the DC supply circuit is positive. , a communication circuit section is provided which operates with the supply voltage supplied from the DC supply circuit when the polarity of the supply voltage supplied from the DC supply circuit is reversed and becomes negative polarity, and the communication circuit The incoming circuit section is provided with a switch that operates in different states, and during standby, the supply voltage supplied from the DC supply circuit is of positive polarity and the switch provided in the incoming circuit section is turned on. By doing so, the supply voltage is applied to the incoming call circuit, and when a call is received, the incoming signal from the incoming signal generating circuit is superimposed on the supply voltage supplied from the DC supply circuit and applied to the telephone. The incoming call circuit section outputs a ring tone based on the incoming call signal, and when answering, the switch provided in the incoming call circuit section is turned off, thereby operating the telephone link switch means and the polarity reversing means, respectively, and supplying direct current. The communication signal is superimposed on the supply voltage from the circuit to enable transmission, and the polarity of the supply voltage from the DC supply circuit is reversed, and the signal is transmitted from the DC supply circuit via a switch provided in the communication circuit section. Telephone switching equipment configured to apply said supply voltage of.