FI73105B - EN APPARAT FOER KOPPLING AV SAMTAL FRAON TVAO TELEFONANSLUTNINGAR TILL EN TELEFONAPPARAT. - Google Patents

Description

χ 73105

A device for connecting calls from two subscriber lines to one subscriber device

The invention relates to a device which automatically connects a telephone or other subscriber device from two subscriber interfaces to the one to which the call is received.

Often, two subscriber interfaces from a telephone exchange are connected to office rooms or similar premises, to each of which a telephone or other subscriber equipment is connected. This allows you to call the office by dialing one of the two phone numbers.

Normally, phones are placed so that they are on the desks of different people. If the person is not at his desk due to a temporary absence, the answer to the 15 calls in question must be moved to k.o. to the phone. This causes an extra waste of time.

Another difficulty in an office with two phone lines arises when you want to use an answering machine. When using conventional answering machines, two answering machines are needed, which becomes expensive and impractical.

The above drawbacks can be eliminated by using the device according to the present invention. Two incoming telephone lines and two telephones 25 or other subscriber equipment are connected to the device. The device works as follows: If one of the telephone lines receives a call and there is no ongoing call on the other line, the device automatically connects the desired telephone line to that line. In this way, calls to both telephone lines are routed, if necessary, to the same telephone machine previously selected by the switch. With the device now shown, for example, two telephone lines can be monitored simultaneously by one answering machine.

For the same purpose, the so-called manager-35 secretary telephone systems, but they require additional wiring, specially designed telephones, and cannot be used to replace answering machines. Similarly, 73105 few switching devices have been published for answering machines, but they use a separate power supply instead of a telephone network and do not include the selection of a target device.

In the following, the invention will be described in detail with reference to 5 figures.

Figure 1 shows a block diagram of the device.

Figure 2. shows in more detail the structure of the selection block in the device.

The invention consists of a device (fig.) Which is connected to 10 telephone subscriptions with two-wire cables 1 and 2. Two telephone machines or a similar subscriber device with two-wire cables 3 and 4 are also connected to the device. with separate sockets and plugs. Block 5 is an electronically implemented selector 15 which derives its own power from the operating voltage of the telephone network and which, when the ringing voltage enters one of the two input lines T1 or T2, connects its output line L to that input line. In addition, block 5 prevents the state from changing from the incoming call voltage if the loop current is already passing through block 5 20, in other words a telephone connection already exists on either line T1 or T2.

The operating mode of the device can be selected via a three-position switch 6. In the arrangement according to Fig. 1, for example, when the switch 6 is in the middle position, both lines and telephones operate independently, in other words in position respectively for the ti-30 wide device 4.

One implementation of the selector block 5 is shown in Figure 2.

The selector block 5 has a bi-stable changeover relay 7 with two windings, the switching state of which is changed when the ring-detection voltage detection circuits 8 or 9 detect a ringing pulse on the input line which does not correspond to the current switching state. The switching state of the switching relay 7 is changed by discharging the charged capacitor 10 into the respective winding of the relay 7 by means of the switching units 11 or 12. Information on the existence of a ringing voltage for the switching units on one of the two input lines is obtained from the ringing voltage detection circuit on the line, for example via an opto-isolator. The condenser 5 is charged from the quiescent line voltage of the telephone network by means of a diode bridge 13 and a constant current generator 14.

The function of the loop current monitoring circuit 15 is to prevent the device state from changing due to the ringing voltage coming to the non-connected input line, if there are already 10 calls going on on the other line. The change of state can be prevented, for example, by discharging the capacitor 10 while the loop current passes through the optoisolator in the monitoring circuit 15. Discharging can take place by a transistor 16, which can also be a transistor of an optoisolator in said monitoring circuit 15.

15 The above activities can, of course, also be carried out in many other ways and structures.

Claims (3)

4 73105 A device which, when so set, automatically connects a telephone or other subscriber unit from two subscriber-5 subscriptions to the receiving party, characterized in that the line is switched by a bistable switching relay (7) using a constant current charged to the capacitor (10) electric energy. Device according to Claim 1, characterized in that the automatic control function is either bypassed or the calls are selected to be routed to one of the two subscriber device connections (3, 4) of the device by means of a switch (6) or the like. Device according to claim 1, characterized in that the loop current of the telephone line connected via the device is monitored by a special monitoring circuit and when the loop current exceeds a predetermined threshold value the capacitor (10) is discharged and thus prevents the relay (7) from changing state during an ongoing call. .f