JPH03145849A - Telephone set - Google Patents

Abstract

PURPOSE:To save a trouble of redialing for callback even when talking is interrupted due to power failure or the like by connecting a mechanical switch selected from the OFF state into the ON state in parallel with an electronic switch when a power supply supplied to each circuit component including an electronic switch is interrupted. CONSTITUTION:When a power supply supplied to a control section 8 or the like of a master set due to a power failure or the like is interrupted in the talking state, a relay 5 keeping the OFF state is closed. As a result, the power supply is interrupted, the electronic switch 4 is opened but the relay 5 is closed, then a telephone line connected so far, that is, the DC loop of a trunk line is kept closing. Then in this case, since a transmission section 14 and a reception section 15 of a master set are inactivated, the talking by the slave set 19 is disabled and the talking with an opposite terminal equipment is again attained by lifting up a handset of a general telephone set 2 provided in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a telephone device equipped with an electronic switch for closing or opening a DC loop of a central office line, and is used in, for example, a cordless telephone.

(Prior Art) In a conventional cordless telephone equipped with an electronic hook switch for closing or opening the DC loop of the central office line, if the supply of commercial power is cut off due to a power outage or the like during a call, the controller of the base unit Since the wireless unit that performs wireless communication with the base unit and the slave unit becomes inactive, the wireless line between the base unit and the slave unit is disconnected, and the electric hook switch also becomes inoperative. , the direct current loop of the central office line was opened, making it impossible to make calls.

(Problem that the invention aims to solve) As a result, the call is interrupted midway through, and the user must either switch to a conventional landline telephone and dial the other party again, or wait for the other party to call. There were some problems. In addition, if you do not have a regular telephone, there is also the problem that you cannot talk to the other party until the power outage is lifted, that is, until commercial power is supplied to the control unit, wireless unit, etc. again.

The present invention has been made in view of the above circumstances, and its purpose is to provide a telephone device equipped with an electronic hook inch.
To provide a telephone device capable of continuing to make a call even if a power outage or the like occurs during a call.

(Means for Solving the Problems) In order to solve the above problems, the telephone device of the present invention includes an electronic switch for closing or opening a direct current loop of a central office line. A mechanical switch that switches from an off state to an on state when the power supplied to the electronic switch is cut off is connected in parallel to the electronic switch.

(Function) When commercial power is supplied to each circuit component including the electronic hook switch of the telephone device, the mechanical switch remains off. This mechanical switch is composed of, for example, a race piece.
Use a type of relay that turns off when current is flowing through the relay coil, and turns on when current does not. Further, in the call standby state, the electric switch is also in an off state (that is, on-hook state B). In this state, if the user picks up the handset in response to a call from the other party's terminal (in the case of a cordless phone, the handset goes off-hook), the electronic switch will turn on. A call line with the other party's terminal is secured. In this way, if the power supply voltage supplied to each circuit part of the telephone device is cut off due to a power outage or the like during a call, the electronic switches that were previously on will also be turned off. However, when the power supply voltage is cut off at this time, the mechanical switch is turned on, and the DC loop of the telephone line, that is, the office line, remains closed. Therefore, if you connect a regular telephone in parallel to this telephone device,
By picking up the handset, the user can continue the conversation with the other party.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The drawing is a block diagram showing the electrical configuration of a base unit of a cordless telephone according to an embodiment of the present invention.

In the figure, a telephone line (office line) 1 that connects to a terminal on the other end (not shown) is connected to a general telephone 2 and connected to an electronic switch 4 made of a PNP transistor via a rectifier circuit 3. connected to the emitter. The base of the electronic switch 4 is connected via a resistor R1 to the collector of an NPN transistor (transistor switch) 4' whose emitter is grounded and whose collector is connected to the control unit 8 via a resistor R2. The collector of the electronic switch 4 is connected to a 2-wire to 4-wire conversion circuit 12.

The output of the 2-wire to 4-wire conversion circuit 12 is sent to the antenna 1 which forms a wireless line 20 with the handset 19 via the transmitter 14.
8, and the input of the 2-wire to 4-wire conversion circuit 12 is connected to the antenna 18 via the receiving section 15. Further, a signal indicating a hold tone is outputted from the hold tone output circuit 13 to the 2-wire/4-line conversion circuit 12 . The 2-wire to 4-wire conversion circuit 1-2 receives a message transmitted from the other party's terminal via the telephone line 1 after the base unit and the slave unit 9 have established a wireless communication channel via the wireless line 20. It has a function of transmitting an audio signal to the transmitter 14, receiving an audio signal transmitted from the handset 19 via the receiver 15, and transmitting it to the other party's terminal via the telephone line 1.

On the other hand, the commercial power supplied via the plug 17 is transmitted to the control section 8, the transmitting section 14, and the receiving section 15 via the power supply circuit 16.
The control unit 8 is supplied with the output of a ringer detection circuit 7 connected to the telephone line 1. Also,
The control section 8, the transmission section 14, and the reception section 15 are bidirectionally connected, and the control section 8 receives the detection signal from the ringer detection circuit 7 and various signals from the transmission section 14 and the reception section 15. Based on this, activation and operation control of the transmitter 14 and the receiver 15 are performed.

Further, the control section 8 is connected to the input of a ringer sound generation circuit 9 which controls the drive based on the detection signal from the ringer detection circuit 7 . It is connected to the speaker 11 via.

On the other hand, a relay 5 is connected in parallel to the electronic switch 4. That is, one end of relay 5 is on the emitter side,
The other end of the relay 5 is connected to the collector side. The output of a drive circuit 6 driven by a control signal from a control section 8 is guided to a coil 5a of the relay 5. That is, when the relay 5 is supplied with commercial power, the coil 5a is excited by the control signal from the control unit 8 and is in the OFF state, and when the supply of commercial power is cut off due to a power outage, etc. At this time, the supply of current to the coil 5a is stopped and the coil 5a is turned on.

Next, the operation of the cordless telephone with the above configuration will be explained.

First, in the initial state of call standby, the relay 5 is turned off by the control signal from the control section 8, and the electronic switch 4 is also turned off by the control signal from the control section 8.
Since it is at a low level, it proves that it is in an off state.

In this state, when a calling signal is sent from the other party's terminal via the telephone line 1, the ringer detection circuit 7 detects this and sends the detection signal to the control section 8. The control section 8 drives the ringer sound generation circuit 9 based on the input detection signal, and sends out the ringer sound from the speaker 11 via the amplifier 10. At the same time, the controller 8 drives the transmitter 14 to form a wireless line 20 with the handset 19, so that the handset 19 also transmits a ringer sound.

Then, in response to this ringer sound, the user
When you go off-hook, this off-hook signal is sent to wireless line 2.
0, is received by the receiving unit 15 via the antenna 18 of the base unit, and sends a signal to the control unit 8 indicating that the slave unit 19 is off-hook.

The control unit 8 controls the transistor switch 4 based on this signal.
Since a signal at the "I" level is sent to the base of the transistor switch 4', a current flows between the base and emitter of the transistor switch 4', and the transistor switch 4' becomes conductive. When the transistor switch 4' becomes conductive, the electronic switch 4
The base resistor R1 of the transistor switch 4' is grounded via the collector emitter of the transistor switch 4', and current from the telephone line 1 flows between the emitter and emitter terminals of the electronic switch 4, and the electronic switch 4 becomes conductive (turns on).

This makes it possible to talk.

On the other hand, when making a call from the telephone to the other party's terminal, the user first puts the handset 19 in an off-hook state, and then dials the telephone number of the other party's terminal. This dial signal is from radio diagram vA20, receiving section 15.2 line-4.
Line conversion circuit 12, electronic switch 4 (already turned on by off-hooking the handset 19).

) and the rectifier circuit 3 to the telephone line 1, and sends a calling signal to the other party's terminal. When the other party's terminal responds to this, a response signal is sent to the telephone, thereby establishing a communication path with the other party's terminal and making it possible to talk.

In such a call state, if the power supply to the control unit 8 of the base unit is cut off due to a power outage, etc.,
Since the control section 8 is in a non-operating state, the drive circuit 6 that was being driven until then is stopped by the control signal from the control section 8, and the supply of current to the coil 5a of the relay 5 is stopped. Therefore, the relay 5, which had been kept off until then, is turned on.

As a result, the power supply is cut off, and the electronic switch 4 is turned off, but the relay 5 is turned on, so the DC loop of the telephone line, that is, the office line that was connected until then, is closed. It remains tied. In this case, the transmitter 14 and receiver 15 of the base unit
Since the handset 19 also becomes inactive, it becomes impossible to make a phone call using the handset 19, but by picking up the handset of the parallel telephone 2, it becomes possible to talk to the other party's terminal again.

Note that the hold tone output circuit 13 is for transmitting a hold tone to both the handset 19 and the other party's terminal when the call is put on hold by operating the handset 19. etc., when the power is cut off, it operates with the power from the telephone line 2, and transmits the hold tone to the other party's terminal via the telephone line 1, and stops sending the hold tone when the general telephone 2 goes off-hook. It is possible to configure In this way, even if a call is interrupted due to a power outage only on the telephone side, there is no fear that the other party will hang up, further improving usability.

(Effects of the Invention) In the telephone device of the present invention, a mechanical switch that switches from an OFF state to an ON state is connected in parallel with an electronic switch when the power supplied to each circuit component including the electronic switch is cut off. Therefore, even if a call using this telephone device is interrupted due to a power outage, etc., the direct current loop of the office line remains closed, so the call can be resumed by picking up the handset of a parallel telephone, etc. can do. This also saves the trouble of having to dial again to make a call.

[Brief explanation of the drawing]

The drawing is a block diagram showing the electrical configuration of a base unit of a cordless telephone according to an embodiment of the present invention. 1... Telephone line 3... Rectifier circuit 5... Relay 14... Transmitting section 16... Power supply circuit 2... General telephone 4... Electronic switch 8... Control section 15.・Receiving section

Claims (1)

[Claims] 1) In a telephone device equipped with an electronic switch for closing or opening a direct current loop of a central office line, when the power supplied to each circuit component including the electronic switch is cut off, A telephone device characterized in that a mechanical switch that switches from an off state to an on state is connected in parallel to the electronic switch.