JPH0213520B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for communicating with a central office line during a power outage in a call switching system that is equipped with a call path switch in the central unit of an automatic private branch exchange, key telephone, etc., and is remotely controlled from a terminal. It is related to a circuit that makes it possible.

Conventionally, for station line transfer during power outages as described above,
Private branch exchange equipment is equipped with a battery to maintain a minimum number of calls, and uses the battery's power to maintain the connection state of the call path switch, and a call current monitoring relay is inserted in series with the central office line to detect the end of a call. A configuration is used in which a relay is inserted to monitor the voltage between one of the station lines and the ground. However, these configurations have drawbacks such as requiring large capacity batteries, deteriorating call quality, and requiring a connection between the device and the ground.

The present invention, in order to eliminate these drawbacks,
Control signal transmission cables and power supply cables, which have recently begun to be widely used, are used as bypass circuits in the event of a power outage for communication path switches, which maintain the connection state only when energized. The present invention provides a telephone device in which, by operating the switch, a central office line can be connected to a telephone communication circuit through the side path during a power outage, thereby making it possible to make a telephone call.

The present invention will be explained in detail below using the drawings.

The figure shows an embodiment of the present invention, in which 1 and 11 are control signal conversion circuits, 2 is a relay for power failure switching, and 2-
1 to 2-4 are contacts of relay 2, 3 and 12 are transformers, 4 to 7, 9, and 10 are diodes, 8 is a channel switch matrix that maintains the connection state only when electricity is applied, 13 is a power supply smoothing circuit, 14 is a manual operation switch, 14-1 and 14-2 are contacts of the switch 14, 15 is a telephone communication circuit, 16 is a capacitor, 100 is a main equipment (ME), 200 is a button telephone (KT), 20 is a communication line, 21 is a pair of wires normally used for transmitting control signals and supplying power. The relay 2 and its contacts 2-1 and 2-2 constitute a power failure switching circuit. Further, the figure only shows the part related to the switching call during power transmission of the key telephone device, and the other parts are omitted here because they are not related to the present invention and can be realized by known means.

Next, the operation of the illustrated embodiment will be explained. Now, when the power is on, the telephone communication circuit 15 is switched to the switch 14- by manually switching the switch 14 to the solid line side.
1, 14-2 are connected to the central office line via a telephone line 20 and a telephone line switch matrix 8, and are capable of making telephone calls. Also, at this time, transmission of control signals and power supply between the main device 100 and the key telephone 200 are as follows.
This is done using the pair of wires 21. Among them, the control signal is generated by the operation of relay 2.
→ Capacitor 16 → Transformer 12 → Diode 9
→ the other pair of wires 21 → the dotted line of contact 2-1 → transformer 3 → ground] An AC loop is formed by the route,
The control signal input/output of the main device 100 is inputted to the transformer 3 via the control signal conversion circuit 1, transmitted to the transformer 12 via the above route, and further transmitted as the control signal input/output of the button telephone 200 via the control signal conversion circuit 11. Reportedly. In addition, power is supplied from the main device 100 to the button telephone 200 through the following steps: [power supply → transformer 3 → dotted line of contact 2-2 → one of the pair wires 21 → transformer 12 → power smoothing circuit 13 → power input section of each circuit. →Power supply smoothing circuit 13→Transformer 12→
Direct current is supplied through the route of diode 9 → the other pair of wires 21 → the dotted line of contact 2-1 → transformer 3 → ground]. As described above, a line for the power supply, control signals, and calls necessary for the function of the button telephone device when energized is formed.

Next, when the system stops, the power is cut off, so the relay 2 is restored. At this time, the communication path matrix 8
The connection state between the main device 100 and the telephone 200 is also released. Here diode 4~
Reference numeral 7 constitutes a rectifier circuit for always obtaining an output with a constant polarity in response to changes in the polarity of the station line. Also, when the switch 14 is pressed to switch to the dotted line side, if the polarity of the office line is now on the upper side (+), the communication circuit 15 will change to [office line (upper side) → diode 4 → solid line of contact 2-1 → pair One side of line 21 → diode 10 → dotted line of switch 14-2 → communication circuit 15 → switch 14-
1 dotted line → the other pair of wires 21 → solid line of contact point 2-2 →
Diode 7 → Office line (lower side)] is connected to the office line to enable telephone calls. Here, transformer 1
The diode 9 prevents direct current from flowing in the second direction.

As can be understood from the above description, the telephone device of the present invention is configured such that the main device 1 maintains the connected state only when the power is turned on, and releases the connected state when the power goes out.
In a telephone device configured such that a telephone line 20 of a telephone 200 is connected to a central office line via a telephone line switch 8 provided at a pair of cables 21, and a power-on side contact and a power-off side contact for connecting the telephone communication circuit of the telephone to the telephone side of the telephone line when the power is on, and to the telephone side of the pair of cables during the power outage, respectively, by manual switching. a manual changeover switch 14 having the following: a DC power source having an output terminal that outputs a required DC output voltage when energized; and a full-wave rectifier connected between the office lines so as to extract the DC output voltage from the office line. The circuits 4, 5, 6, 7 and the main device side of the pair of cables are connected between the output terminals of the DC power supply, or a voltage of opposite polarity to the DC output voltage of the DC power supply is connected to the central line. Cable switching circuits 2-1 and 2-2 connected to the output side of the full-wave rectifier circuit so as to be supplied from the DC power source via the rectifier circuit, and the main device side of the pair of cables, when the DC power source is energized, connected between the output terminals of the DC power supply,
a cable switching control circuit 2 that controls the cable switching circuit so as to be connected to the output circuit of the full-wave rectifier circuit when the DC power supply is out of power; a diode 9 inserted between the pair of cables and the power supply circuit on the telephone side so as to be in the forward direction with respect to the direct current flowing in the power supply circuit of the telephone; a diode 10 disposed between the pair of cables and the telephone communication circuit so as to be in the forward direction with respect to the direct current flowing through the circuit and the pair of cables to the telephone communication circuit of the telephone; have.

As explained above, the polarity of the DC voltage is switched between when electricity is on and when there is a power outage, thereby making it possible to transmit two types of information using a pair of cables: when electricity is on and when there is a power outage.

As explained above, according to the present invention, a switching machine,
In telephone systems such as pushbutton telephones and line concentrators, where the central device is equipped with a call path switch that maintains the connection state only when the power is turned on, calls can be made during power outages without using conventional batteries or line monitoring relays. This enables switching.

[Brief explanation of drawings]

The figure shows one embodiment of the invention.

Claims (1)

[Scope of Claims] 1. The telephone line is connected to the central office line via a line switch provided in the main device so that the connected state is maintained only when the power is turned on and the connected state is released when the power goes out. In the telephone device configured as above, a pair of cables are provided between the main device and the telephone separately from the telephone line, and a telephone circuit of the telephone is connected to the telephone side of the telephone line when the electricity is energized, and a cable is connected to the telephone side of the telephone line during the power outage. a manual changeover switch having an energizing side contact and an outage side contact for connection to the telephone side of the pair of cables by manual switching; and a DC power source having an output terminal that outputs a required DC output voltage when energized. A full-wave rectifier circuit connected between the office lines so as to extract a DC output voltage from the office line, and a main device side of the pair of cables connected between the output terminals of the DC power supply, or a cable switching circuit connected to the output side of the full-wave rectifier circuit so that a voltage having a polarity opposite to that of the DC output voltage is supplied from the office line via the rectifier circuit; and a main device of the pair of cables. a cable switching control for controlling the cable switching circuit so that when the DC power supply is energized, the cable switching circuit is connected between the output terminals of the DC power supply, and when the DC power supply is out of power, the cable switching circuit is connected to the output circuit of the full-wave rectifier circuit; a circuit between the pair of cables and the power circuit of the telephone so that the direct current flows from the DC power source to the power circuit of the telephone through the pair of cables when the current is energized. the pair of cables and the telephone so that the direct current flows in the forward direction from the office line to the telephone communication circuit of the telephone via the full-wave rectifier circuit and the pair of cables during a power outage; A telephone device comprising: a diode disposed between a telephone circuit and a telephone circuit.