DE167579C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

The invention relates to a telephone circuit with an office battery and two-contact plugs and pawls, namely a circuit of the type in which the pawl system is permanently connected to the subscriber twin line, and between the subscriber station and the office two relays are switched on, one of which causes the call and the other to do so

ίο is used to switch off the call device when the conversation should begin.

In such a device, the problem arises that the isolating relay the Must allow streams of speech to pass freely, even though it is energized from the office battery at the same time. The invention, by this problem is solved essentially in that the isolating relay with two oppositely connected windings is provided, which in the two branches of the Subscriber line are switched on and arranged in such a way that one is de-energized, when the connection is plugged. The current of speech can pass unhindered through the windings, as they are mutual cancel their self-induction while the callsign remains off for as long the connection is plugged.

In the drawing is the arrangement

.30 shown schematically. A and B are the two subscriber stations, which in their simplest form consist of the capacitor 5 and the alarm clock 4, to which the microphone 6, the receiver 7 and the hook contact 8 form a bridge. The two branches 2 and 3 of the subscriber double line L are permanently connected to the two poles of the battery B by the lines 2 ^a and 10 on the one hand and 3 ^{a and 12 on the other hand.} In the lines 2 ^a and 3 ^a , the two windings of a call relay R are turned on, the contact with the help of a line 15 and line 10 closes a local circuit in which the call lamp S is located. At the juncture of the leads 2 and 3 with the leads 2 ^a and 3 ^a are branched off two lines 13 and 14, which two oppositely connected windings of an isolation relay R ₂ form and then immediately cause the pawls J. The circuitry of the plug device and the office is only given to show that the system works with an office battery for the purposes of calling, interrogating, checking, monitoring and issuing the end-of-line signal and requires only two contacts in each of the plugs and handles.

The process that takes place when connecting two participants is as follows. A subscriber connected to the double line L takes the receiver off the hook; this creates a circuit from the battery B via line ro and 2 ^a , through the winding 9 of the relay R, line 2, hook 8,

Claims (1)

7 handset, the microphone 6, line 3, winding 11 of the closed relay R 3 ^a line 12 and to the other pole of the battery B. This current energizes the signal relay R, creating a local circuit from the grounded battery B via conductor 10, call lamp S, conductor 15, armature of relay R, armature of relay Pv ₂ to earth. As a result, the lamp 5 lights up and the officer inserts the interrogation plug P into the latch J and queries with the aid of the key 19. The insertion of the plug P includes the following circuit: From the battery B via conductors 28 and 27 through Uberwachungsrelais r _2, via the cord, on the part of the double line, which-the winding 14 of the isolation relay R ₂ contains, by winding 11 of the.? Signal relay R and conductor 3 ° to the other pole of battery B. This current excites relay R ₂ , so that it attracts its armature and thereby opens the local circuit of lamp S. After the officer has learned the number of the desired subscriber, he checks the line to be busy in a known manner by holding _{the plug P 2 on the next multiple jack of the desired subscriber.} If the line is free, he inserts the plug P ₂ into the latch J. Inserting the plug brings the isolating relay Pv _{2 of} the desired subscriber D to respond in the same way as before for the calling subscriber A. It does not matter whether the call relay R also comes into operation at this time, as the local circuit through the call lamp S as is kept open by the isolating relay. By pressing the wake-up button 23, the officer calls the desired participant. The wake-up current flows from the grounded inductor 22 via the tip of the connecting plug P ₂ , the winding 13 of the relay R ₂ , the line branch 2, the capacitor 5, the alarm clock 4, the line branch 3, the other winding 14 of the relay R ₂ , the Body of plug P ₂ , button 23, leads 24 and 10 through battery B to earth. By lifting the handset, the called subscriber completes the speech circuit. During the call, the microphones are mainly fed via the windings of the call relay R , while part of the current flows through the monitoring and _{closing relays r and T 3} . The speech currents go freely through the windings of the isolating relay R ₂ , which do not respond to the large number of changes in the speech currents. Pate ν t-An s PRu c η: Circuit arrangement for telephone exchanges with two-contact jacks and two-contact plugs, with an office battery for speech, call and test currents, as well as with a jack system permanently connected to the subscriber double line, in which the switch-off relay (R ₂ ) is in the speech circuit and the subscriber double line (2, 3) in the office two branches (2 ^a and 3 ^a , 13 and 14) are branched, of which one pair (2 ^a , 3 ^a ) runs through two windings (9 and 11) that excite the call relay (R) and leads directly to the office battery, while the other pair forms two oppositely connected windings (13 and 14) of the switch-off relay (R ₂ ) and leads to the pawls, characterized in that both relays (RR ₂ ) are connected in such a way that when the connection is plugged, a circuit is formed which only one winding (14) of the switch-off relay (R ₂ ) runs through and thereby switches off the call sign in a known manner, while the speech currents always both windings of the switch-off lais, but not through the call relay (R). 1 sheet of drawings.