JPS5844847A - Button telephone device - Google Patents

Abstract

PURPOSE:To eliminate the need for a backup power supply, by preventing sudden disconnection of lines at power failure, through the changeover of a main trunk to a telephone set for use in power failure automatically, after the transmission of message for a prescribed time on mains failure. CONSTITUTION:When one of a button telephone sets 2 is communicated, then a call current detection section 4 continuously detects a call current and a power failure detection section 13 monitors a voltage of the power supply 10. If power is failed and no power is supplied to a switching circuit 15, the circuit 15 is automatically reset, a main trunk 1 during call is kept with a DC loop closing section 17 and a message representing the generation of power failure is trans- mitted from a message transmission section 18. A switching control section 14 stops the section 18 after a prescribed time and controls the switching circuit 15 to switchingly connect the main trunk 1 to a telephone set 16 for use in power failure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a button telephone device that switches and connects a small number of office lines to a plurality of telephones. In particular, the present invention relates to a button telephone device that maintains a communication path using a relay circuit.

Traditionally, when a power outage occurs with this type of button telephone device,
This has the disadvantage that the relay circuit that maintains the communication path no longer operates, resulting in the line being suddenly disconnected without any notification to the other party. In order to prevent this, a method of knocking up the line using a battery is known, but this requires a complicated circuit to maintain the line during a power outage and requires a large-capacity battery.

The present invention improves this point, and aims to provide a button telephone device that can prevent the line from being suddenly disconnected during a power outage and does not require a power source.

The present invention is configured to prevent a call from being suddenly disconnected in the event of a power outage, and to automatically switch the central office line to a power outage telephone after sending a message for a certain period of time. Patent Features The present invention includes a power outage detection unit that detects a power failure from a commercial power source, a call current detection unit that detects the call current of the office line during a call, and a DC loop provided for the office line. a closing unit; a message sending unit for sending a message to the active line to the effect that a power outage has occurred;
including a small-capacity battery power source for supplying power to the Luzo closure unit and the message sending unit immediately after a power outage;
When there is a detection output in the power outage detection section and the telephone call t detection section, the Luzo closing section is activated by the battery power supply to hold the telephone line in use, and the message transmission section sends a message to this telephone line. After that, the central office line is controlled to be connected to the power outage telephone.

An embodiment of the present invention will be described based on the drawings.

The figure is a block diagram of a narrow section according to an embodiment of the present invention. The figure is a diagram focusing on one of the plurality of accommodated station lines, where 1 is the station line terminal for connecting the station line, and 2 is the button 1! of the plurality of stations. Each phone is shown. button phone 2
is connected to a line switching section 3 that performs switching connection between the central office line and the two-tone telephone.

Connected to this line switching section 3 is a call current detection section 4 that detects the first rate of communication on the central office line during a call. This communication current detection section 4 is connected to the office line terminal 1 via a switching circuit 5. Control signals from a control circuit 6 are guided to the button telephone 2 and the line exchange section 3, respectively.

Further, in the figure, 8 is a commercial power supply input terminal, to which the first and second power supply units 9 and 10 are respectively connected. This power supply section 9 supplies power to each of the circuits. A power failure detection unit 13 is connected to this power supply unit 9 to detect disconnection of the commercial power source. The output of this power outage detection section 13 is the switching control section 1
It is guided by 4. The switching control section 14 is connected to the communication current detection section 4 . In addition, this switching control section 1
The 40 control signal is routed to the switching circuit 150 control terminal. A power outage telephone 16 is connected to the first contact a2 of this switching circuit 15. The output of the DC loop closing section 17 is led to the second contact b2 of the switching circuit 15.

The output of a message sending section 18 consisting of a voice synthesizer, tape recorder, etc. is led to this DC loop closing section 17. This message sending section 18, DC loop closing section 1
The control signals of the switching control section 140 are respectively guided to the terminals 7 and 7.

Here, the power supply section 10 is connected to each section (13, 14, 15) during a power outage.
, 17, 18), and each part (13, 18) is equipped with a rechargeable battery to supply power to the parts (13,
4, 15, 17, 18) and is configured to charge the battery.

The characteristic operation of the present invention will be explained using such a circuit configuration. In normal times when commercial power is supplied from the power supply section 9, the office line (not shown) is connected to the telephone 12 side via the office line terminal 1 and the contact point of the switching circuit 5. When one of the button telephones 12 performs a call operation, the control circuit 6 connects the central office line and the button telephone 1 via the line switching section 3.
One of the two is connected and a conversation is established. In this state, the communication current detection section 4 continuously detects the communication current. Furthermore, the power failure detection section 13 monitors the voltage of the power supply section 9, and provides that information to the switching control section 14 when the voltage falls below a specified value.

When the switching control section 14 learns that a power outage has occurred from the output of the power outage detection section 13, it accesses the call current detection section 4. As a result, if a call is in progress, the switching circuit 15 connects the common contact to the contact b2, controls the switching circuit 15 to switch to the DC Luzo closing unit 17 (III), and also controls the message sending unit 18.
Start up. At this time, the switching circuit 5 is supplied with power due to a power outage (then it is automatically reset, and the common contact is connected to the contact a1 side, so the central office line during the call is held by the DC loop closing section 17, and the power is turned off.) A message is sent that this has occurred.

Furthermore, the switching control section 14 counts the time since the occurrence of the power outage, and stops the message sending section 18 after a certain period of time sufficient for sending the message has elapsed.

At the same time, the switching circuit 15 is controlled to switch and connect to the power outage telephone 16, which is a central office line. If no telephone current is detected by the telephone current detector 4 when a power outage occurs, the office line is immediately connected to the power outage telephone 16 via the switching circuits 5 and 15.

As explained above, according to the present invention, the central office line is held for a certain period of time during a call at the edge where a power outage has occurred, and after a message is automatically sent to the other party, the telephone is switched to the power outage telephone. Therefore, even if a power outage occurs during a call, the caller will be notified of the power outage before the line is disconnected, so the caller will be able to immediately make a call using a telephone directly connected to the central office line. You can perform necessary operations such as re-calling.

In the device of the present invention, a very small built-in battery is sufficient for sending short-term messages, and if a rechargeable battery is used, there is no need for maintenance. 1: Yes, even if you are not aware that you are using batteries.

[Brief explanation of the drawing]

The figure is a block diagram of main parts of an embodiment of the present invention. 1...Station line terminal, 2...7]? Tan telephone, 3...
・Line exchange section, 4... Call current detection section, 5.15...
- Switching circuit, 6... Control circuit, 9.10... Power supply section, 13... Power outage detection section, 14... Switching control section, 16
...Telephone for power outage, 17 Pa/DC loop closing part, 18
...Message sending section. Patent Applicant NEC Corporation Representative Patent Attorney Takashi De Nao ,i',,,,i,
+'i,;i'-''”

Claims (1)

[Claims] (1) A power outage detection unit that detects power supply cutoff from the commercial power supply, a call current detection unit that detects the call current of the office line during a call, and a DC loop closing unit that is designed to correspond to the office line. , a message sending unit for sending a message to the active line to the effect of a power outage, and a small-capacity battery power supply for supplying power to the Luzo closing unit and the message sending unit immediately after the power outage. and when there is a detection output in the power outage detection section and the call current detection section, the Luzo closing section is activated by the battery power source to maintain the central office line in use, and the message sending section sends a message to the central office line. A button telephone device that is controlled to connect the central office line to a power outage telephone after transmitting.