BG838Y1 - Duplex telephone cassette - Google Patents

Abstract

The duplex telephone cassette can be used as a linear equipment for the connection of two telephone subscribers to one two-wire telephone line. It is distinguished by its simplified electric circuit and considerably reduced losses of introduced resistance in the telephone call tract. The cassette is made of two pairs of input-output terminals (11-12, 21-22) for connection, respectively, to the two duplex interconnected telephone subscribers (1, 2) and for connection to telephone line (3). To each of the terminals (31-32) one diode (15, 25) each and a control unit (10, 20) are connected with their anodes, respectively. Each of these units comprises a relay (13, 23) with two pairs of switching contacts (131-132, 231-232) and a capacitor (16, 26) connected to it in parallel. The cathodes of diodes (15, 25) are arranged across the open position of the first switching contacts (131, 231) to the second input-output terminal (11, 22) of each of the subscribers (1, 2). The lead of each of the control units (10, 20) is connected across close position, respectively, of the second switching contact (232, 132) of the other control unit (20, 10), to the first input-output terminal of each of the telephone subscribers (1, 2), the second input-output terminal (12, 22) of which is coupled, across closed position of the first switching contact (131, 231), to earth, to which are also coupled, in open position, the second switching contacts (132, 232) or relays (13, 23). The cathodes of diodes (15, 25) are connected simultaneously in a common point, as well as across open position of the first switching contacts (131", 231") of relays (13, 23), to the second terminal (12, 22), respectively, of the two duplex connected telephone subscribers (1, 2).

Description

The utility model refers to a duplex telephone cassette, which is used as a linear device for connecting two terminal telephone lines on a two-wire line to a local automatic telephone exchange.

BACKGROUND OF THE INVENTION

A duplex telephone cassette is known, which consists of two pairs of input-output terminals connected respectively to the first and second duplex telephone post and to a telephone line. One input-output terminal of each pair is connected through a second switching contact of a control unit of the second duplex telephone post in a closed state and through its own control unit consisting of a relay with two switching contacts and in parallel connected to the relay by a capacitor. telephone line and by first switching contact of the other control unit in the open state - to the other input-output terminal of the other duplex telephone post, and the other input-output terminal of each pair is filed through the first switching contact to the ground. Each of the terminals for connection to the telephone line is connected respectively to its anode diode, the cathode of which is respectively fed through the open position of a second switching contact from the control unit of the other telephone post to its second terminal. A diode is connected between each of the terminals on the telephone line and the first input-output terminal of each of the telephone consecutively on the control unit, with a capacitor connected in parallel to it.

The well-known duplex telephone cassette has a complicated electrical circuit due to the inclusion of additional elements in the conversation tract.

The technical nature of the utility model

The task of the utility model is to create a duplex telephone cassette that has a simplified wiring diagram and reduced losses of input resistance in the telephone line.

In accordance with the utility model, this problem is solved by means of a duplex telephone cassette consisting of two pairs of input-output terminals for connection to the two duplex-connected telephone outlets and an input-output pair of terminals for connection to a telephone line. Each diode and control unit are connected to each of the terminals, each consisting of a relay with two pairs of switching contacts and a capacitor connected in parallel. The cathodes of the diodes are fed through the open position of the first switch contacts to the second input-output terminal of each of the telephone posts. The other terminal of each control unit is respectively fed through the closed position of the second switching contact of the second control unit to the first input-output terminal of each of the telephone stations whose second input-output terminal is fed through the closed position of the first switching contact to the "ground" to which the second switching contacts of the relays are placed in the open position. The cathodes of the diodes are connected simultaneously at a common point to each other and to the open position of the first switching contacts of each of the relays of the respective control unit.

The advantages of the duplex telephone cassette are that the distance to telephone is increased; the losses of the call signal are reduced, full independence of the action is guaranteed when taking one telephone post from another; insensitivity to parasitic signal interference in the subscriber tract; possibility for use in tone dialing and for transmitting signals with a frequency of 16 kHz when switching on the telethaxer and transmitting a charging pulse after the telephone is closed by the calling subscriber; increased operational safety; as well as the absence of malicious interference to charge telephone calls from one duplex telephone post at the expense of the other.

Description of the figures

The utility model is explained in more detail by the exemplary embodiment of the duplex telephone cassette shown in the figure with its schematic diagram.

Exemplary embodiment

As shown in the figure, the duplex telephone cassette consists of two pairs of input-output terminals 11-12 and 21-22 for connection to the two duplexly connected telephone stations 1 and 2, and of an input-output pair of terminals 31-32 for connection to telephone line 3. To each of the terminals 31 and 32 are connected respectively to their anode one diode 15 and 25 and a control unit 10 and 20, each of which consists of relays 13 and 23 with two pairs of switching contacts 131-132 and 231 -232 and capacitors 16 and 26 connected in parallel to it. The cathodes of diodes 15 and 25 are connected in common point and n provided through the open position of the first switch contacts 131 and 231 to the second input terminal 12 and 22 of each of the telephone stations 1 and 2. The other terminal of each of the control units 10 and 20 is respectively fed through the closed position of the second switch contact 232 and 132 of the second control unit 20 and 10 to the first input-output terminal 11 and 21 of each of the telephone stations 1 and 2, whose second input-output terminal 12 and 22 is supplied through the closed position of the first switching contact 131 and 231 to "ground" to which they are filed in the opening o position and second changeover contacts 132 and 232 relays 13 and 23.

In addition to each of the capacitors 16 and 26, thermistor 17 and 27 may be further connected to the control units 10 and 20.

Outbound Action:

When lifting the handset from the apparatus of the first telephone post 1 in the wiring diagram of the duplex telephone cassette, the following circuit is closed:

- "minus" from "a" conductor of telephone line 3 through terminal 31, relay coil 13 with capacitor 16 connected in parallel, closed position of second contact 232 'of relay 23 of the second control unit 20, first terminal 11 of open apparatus of first telephone post 1, second terminal 12 of apparatus, closed position of first contact 131 'of relay 13 from first control unit 10 to ground.

In case of a free telephone line in the automatic telephone exchange not shown in the figure, its subscriber facilities are activated, whereby a plus potential is applied to the second terminal 32 to the telephone line 3. After switching on relay 13 of the first control unit 10, the initial current circuit changes as follows:

- '' minus' 'from' a 'conductor of telephone line 3 through terminal 31, relay coil 13 with capacitor 16 connected in parallel, closed position of second contact 232' of relay 23 of the second control unit 20, first terminal 11 of the open apparatus of the first telephone post 1, the second terminal 12 of the apparatus passing from the closed in the first open position the first contact 131 "to the relay 13 of the first control unit 10, the second diode 25, the second input-output terminal 32," c " - wire of telephone line 3, plus in the automatic telephone exchange.

In this situation, the first telephone post 1 is connected to the telephone exchange not shown in the figure and can make an outgoing connection, and the telephone of the second telephone post 2 is electrically insulated completely due to grounding on the following circuit:

- "ground", closed position of first contact 231 'of the second control unit 20, second terminal 22 of the second telephone post 2, its first terminal 21 extending from the initially open second position 132 "of the actuated relay 13 of the first block for government 10, “land”.

The first diode 15 remains in the clogged state and the second diode 25 is in the clogged state and participates in the conversation circuit of the first duplex connected telephone post 1.

Inbound action:

In the presence of a call to the first duplex telephone post 1 from the telephone line 3, a call signal is sent to the first and input-output terminal 31 for telephone line 3, through the first relay 13 and the capacitor 16 connected in parallel, the closed position of the second contact 232 'of relay 23 of the second control unit 20, the first terminal 11 of the first duplex telephone post 1, its second terminal 12, the closed position of the first contact 13 D of the relay 13 of the first control unit 10 to "ground".

During the call, depending on the half wave of the received AC signal, the first diode 15 or the second diode 25 is blocked, so that no second signal is sent to the second duplex telephone post 2 until the first duplex telephone post 1 is shunted for the call signal.

When lifting the handset of the first duplex connected telephone post 1, the electrical circuits described above with an outgoing connection are made.

In both control units 10, 20, a varistor 17, 27 can be further connected in parallel to the capacitor 16, 26, which improves the protection of the duplex telephone cassette against penetration of induced parasitic voltages.

The operation of the duplex telephone cassette at the incoming or outgoing connection of the second duplex telephone post 2 is analogous to the operation of the first duplex telephone post 1.

Claims

Claims (1)

Duplex telephone cassette, consisting of two pairs of input-output terminals for connection to the two duplex connected telephone points respectively and an input-output pair of terminals for connection to a telephone line, each connected to its anode respectively diode and control unit, each consisting of a relay with two pairs of switching contacts and a capacitor connected in parallel, wherein the cathodes of the diodes are fed through the open position of the first switching contacts to the second input terminal. one terminal of each of the telephone stations, the other terminal of each of the control units being respectively fed through the closed position of the second switching contact of the other control unit to the first input-output terminal of each of the telephone stations whose second input-output terminal is applied through the closed position of a first switching contact to a "ground" to which the second switching contacts of the relays are fed into the open position, characterized in that the cathodes of the diodes (15 and 25) are connected simultaneously in common with each other and towards the open position of the first switch contacts (131 ”and 231”) of each of the relays (13 and 23) of the respective control unit (10 and 20). Attachment: 1 figure