JPS58125992A - Key telephone device - Google Patents

Abstract

PURPOSE:To ensure a call to a trunk line by means of a key telephone device, by inserting a diode between a hook switch and a monitor circuit and then inverting the polarity of the trunk line between the service interruption and non- service interruption modes. CONSTITUTION:In a non-serivce interruption mode, a trunk line is connected to a trunk line interface 11 of a primary device by means of a service interruption switching key PFK. Thus an exchange of circuits, etc. are carried out under the control within the primary device. While channels 14 and 15 are connected to channels 20 and 21 of a key telephone device through a telephone interface 12. Thus it is possible to monitor a call. Then the key PFK is switched in a service interruption mode, and the trunk line is connected to the key telephone device. In this case, a diode 19 is set to opposite direction in an off-hook state and by the function of a diode bridge 13. Thus a trunk line loop is cut off. A telephone circuit network 16 is connected in an off-hook state, and the trunk line loop is formed. Then a call becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a button telephone device, and particularly to a button telephone device that allows telephone calls to be made over a central office line even during a power outage.

Traditionally? :、For telephone calls on the central office line during a power outage using the telephone device, a power outage switching key PFK is installed between the central office line and the central office line circuit 1, as shown in Figure 1, and in the event of a power outage, a power outage switching key P is installed.
Activate FK, switch to standalone phone 2, standalone phone 2
A call was secured at .

Therefore, the disadvantage of having to install a stand-alone telephone, which is not normally required, is rare.

The present invention solves the above-mentioned drawbacks by making it possible to make calls on central office lines using a specific key telephone during a power outage, and provides an inexpensive and easy-to-use key telephone. In this case, a plurality of key telephones and the main device are connected by a plurality of pairs of communication paths, and the pairs of communication paths accommodated in the button telephones are connected to the monitor circuit via a 7-way switch in the on-hook state. In the state, in a button telephone device connected to a telephone circuit network, the central office line is connected to the main telephone telephone via the power outage switching telephone key. A power outage switching key is housed in a button telephone via another circuit, and a diode is inserted between the 7-switch switch of the button telephone and the monitor circuit so as to be in the forward direction with respect to the polarity of the pair of communication paths. , during power outage switching key operation, the office line is connected through a diode bridge circuit,
There is obtained a button telephone device characterized in that a diode inserted between a hook switch and a monitor circuit of the button telephone is connected to the pair of communication paths of the button telephone so that the polarity thereof is reversed.

Next, an embodiment of the present invention will be explained with reference to the drawings.
Figure 2 is a circuit diagram of a main part of an embodiment of the present invention. The central office line RI, L, is a switchover key PFKI during a power outage.

The communication path 14.15 from the telephone interface circuit 12 of the key telephone main unit is stopped [II switch] is accommodated in the office line interface circuit 11 of the button telephone main unit through the key telephone main unit In this case, the communication path 14.20 is connected to the positive polarity and the communication path 15.21 is connected to the negative polarity. The off-hook side is connected to the telephone network 16 through a diode 19, and the on-hook side is connected through a diode 19 to a monitor circuit consisting of a line transformer 18 and a speaker 17.

On the other hand, power outage switching keys PFKI, PFK" on the central office line side and power outage switching keys PFK", PFK4 on the button telephone side
is connected via a diode bridge 13. In the figure, only one office line, one button telephone, and the circuit related to the communication path of the main device are shown, and other button telephones etc. are not related to the present invention. Parts have been omitted. 0 Next, we will explain the operation. 0 In the absence of a power outage, the power outage switching key PFK is shown in Figure 2. In good condition, the key is station + IILI, and Lx is connected to the station line interface circuit of the key telephone main unit. are connected, and operations such as multi-line switching are performed under control within the main device. On the other hand, from the telephone interface circuit 12, the communication path 14.15
is connected to the communication path 20.21 of the button telephone, and if a handset is used, the telephone interface 7-base circuit 12←)-communication path 14-
Calls can be made in the loop of "Power cut-off key PFK" - Power path 20 - Hook switch H8 - Telephone circuit network 16 - Call path 21 - Power outage switch key PFK4 - Call path 15 - Telephone interface circuit 12 (to) becomes.

In the case of a monitor, telephone interface circuit 12 (g) ---
...=7 switch H8-Diode 19-Line transformer 18--Telephone interface
Monitoring is possible with the loop of face time w112←).Next, the operation during a power outage will be explained. Power outage ex key p
When -i is switched to H', the central line becomes L1. L
! -Electric key PFKI for switching during power outage, PFK electric diode bridge 13 -Electric key PFKaPFK number for switching during power outage-
At this time, due to the action of the diode-bridge 13, the communication path 20 is determined to have a negative polarity, and the communication path 21 is determined to be a positive polarity. In the closed state, the diode 19 is in the opposite direction, so the central line loop is disconnected. Hook-switch is off. - When hooked, a switching line loop is formed on the telephone circuit network 16 side and a call can be made. - Therefore, the 7-e switch Ha and the telephone circuit network 16 are equivalent to a standalone telephone. It can do the work of

As explained above, the present invention provides an inexpensive and easy-to-use button telephone device that enables calls to a central office line using a key telephone during a power outage, and does not require a standalone telephone for use during power outages. I can◎′

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a conventional circuit, and FIG. 2 is a configuration diagram of a circuit according to an embodiment of the present invention. Ll, Ll... Central line, PFK... Power outage switching key, H8... Hook switch, 1.1
1... Office line interface circuit, 2...
...Single telephone, 12...Telephone inter@
Face circuit, 13... Diode bridge, 14, 15, 20. 21... Communication path, 16.
...Telephone circuit network, 17...Speaker,
18...Line transformer, 19...
diode. Agent Patent Attorney Hajime Uchihara

Claims (1)

[Claims] A plurality of key telephones and the main device are connected through a plurality of communication path pairs, and the number of communication path pairs accommodated in the button telephone is 7.
In the button telephone device, which is connected to the telephone circuit network in the off-click state, the on-fist hook-shaped JilK is connected to the monitor circuit via the switch, and the central office line is connected to the central telephone circuit of the button telephone main device through the power outage switching key, and the button The telephone interface circuit of the telephone main unit and the pair of communication paths are housed in the button telephone via the other circuit of the power outage switching key, and are connected between the 7-took switch of the one button telephone and the monitor circuit. A diode is inserted in the layer direction with respect to the polarity of the communication path pair, and the power failure switching type #11wI
(b) When in operation, the central office line is connected to the communication line pair of the button telephone via a diode ψ bridge circuit in such a way that the diode inserted between the hook switch of the button telephone and the monitor circuit has opposite polarity. A button telephone device featuring: