DE443905C - Circuit arrangement for telephone systems with intermediate amplifiers - Google Patents

Description

The invention is based on the idea of telephone lines equipped with amplifiers To transmit voter surges and thereby suitable lines of this type for automatic telephone operation for which they have not yet been used.

Because of the mostly inductive coupling of the amplifiers with the long-distance line and

ίο this with the official and subscriber lines let the voter DC surges with their full Duration must be received at the receiving point, not without further ado via the Transmission of the trunk line to the receiving center. The implementation of the invention is based lying thought can be achieved in various ways. You can z. B. the voter surges through the first amplifier and using suitable relay relay from amplifier to amplifier forward to the receiving point, or a carrier frequency by means of the voter surges control that is sent by the amplifier over the line and at the receiving end for the purpose of actuating a surge relay, through which the voter surges are reproduced, is rectified. The amplifier can also be bypassed by using suitable relays to reduce the current impulses either passed on from repeater station to repeater station by means of a call relay or a bypass relay that precedes the selector surges actuated, which switch off the amplifiers and connect the line sections to one another, whereupon the call through the connected line by means of the 'to' of the transmitting station given current surges occurs. Or the pipeline sections are ordinary directly connected to allow the voter surges to exceed unhindered, and the amplifiers are temporarily used for the call only after successful dialing switched on.

Some exemplary embodiments of the invention are explained below.

I. Transfer using the Amplifier.

A. By sudden shift in grid tension.

Fig. R shows a repeater circuit in the cable run. B. from the trunk line F ₁ into the primary winding of the ring transformer RU ₁ terminating the trunk line. The induction impulse transmitted after the secondary winding closes via the two primary windings of the equalizing transformer AO ₁ and the artificial line K ₁ . In the secondary winding of the equalizing transformer, a current surge is again induced, which closes _{via the primary winding of the pre-transformer FiJ 1.} The induced current impulse transmitted to the secondary winding shifts the grid potential of the amplifier tube V ₁ so strongly in the positive sense that the xA node current of the tube reaches its saturation value. The relay Ji _{1 speaks with this}

*) The patent seeker indicated the following as the inventors:

Bruno Pohlmann in Berlin-Siemensstadt and Dr.-Ing. August Engelhardt in Berlin-Haiensee.

in the anode circuit, and its normally open contact causes the transmission relay IR ₂ to respond. Its changeover contacts separate the ring transformer RV _2, which terminates the further long- distance line F ₂ , from the amplifier circuit and apply it via the protective resistor W to a suitably selected part of the anode voltage. A current surge of the appropriate strength flows through it

ίο the primary winding of RC ₂ and arrives, transmitted inductively, in the long- distance line F ₂ . The relay R ₁ is provided with such a drop-out delay that the transmission relay IR., Remains energized long enough to develop the current flow through the primary winding of RU ₂ to full strength. allow. A strong induction shock therefore goes into the long-distance line. Instead of the relay R ₁ , the drop-out delay can also be used

be provided in the transmission relay IR ₂ itself.

An additional working contact of IR., Short-circuits the input of the amplifier V ₂ during the work process to prevent whistling, which would otherwise occur, since the equilibrium of the compensation circuit is disturbed by disconnecting the ring transformer RC from the amplifier. The incoming induction surges must in each amplifier the grid potential in a certain, z. B. relocate in a positive sense, which is why it is important to pay attention to line crossings and correct connection of the transformer winding ends over the entire line path.

B. By means of carrier frequency.

The Fig. 2 shows the terminal circuit, as far as it is necessary for the understanding of the invention is required.

The running dial NS places a source of modulated, ie periodically interrupted carrier frequency (e.g. a frequency of 500 periods per second modulated in the call rate of 25 periods per second) via the normally open contacts of the pulse generator IG and the normally closed contacts of the call. Switch RU to the plug of the remote cord that is plugged into the jack of the remote line F. A corresponding number of the selected number of bumping modulated carrier stream passes through the pipeline and all the switched intermediate amplifier V to the other end office. The modulated current arriving there arrives at the remote handle and the remote cord plug inserted in it, the normally closed contacts of the call switch RU and the current impulse generator. IG in. The sieve chain .S ", which only lets through the selected carrier frequency. Via the pre-transformer VU , the shocks reach the grid of the sketched rectifier tube and are converted by this into groups of 25-period half-waves, which relay R in the anode circuit, which is matched to this number of periods Excite number disc bumps sent in cycle dt-r. The sensitive relay R controls the voter in the receiving office via an auxiliary relay HR.

The filter chain 6 "is required so that R does not respond to normal ringing currents. Instead of the modulated carrier frequency, alternating current of speech frequency controlled by the voter surges could also be sent over the line in / cycles of the voter surges and converted into direct current surges at the receiving end by rectification in a known manner .

II. Transfer
bypassing the amplifier.

A. By means of further call relay IR.

Fig. 3 shows a repeater circuit V in the line with the relays added. B. incoming direct current surge from the long- distance line F ₁ reaches the primary winding of the ring transformer RU ₁ . The induction current transmitted to the secondary winding excites the bridge relay _{Rf 1} , whose normally open contact excites the transmission relay IR. Meanwhile, W ^r echselkontakte disconnect the further pipeline F "final ring transmitter RU ₂ of DER amplifier circuit, and applies it to a direct current source of appropriate voltage, eg. B. a suitable part of the anode voltage. An induction current is induced in the secondary winding of RU ₂ , which reaches the long-distance line F.

The relays Rf ₁ and IR ₂ must work fast enough to handle the individual selector currents, e.g. B. 10 per second to transfer cleanly. Incoming ringing current with an expediently higher number of periods than the currently used 25 periods, however, causes permanent closure of the normally open contact _{of Rf 1} . This means that the transmission relay IR ₂ initially speaks to uni again sends an induction surge to the long-distance line F ₂ , then the W ^{7 with a} pick-up delay relay R ₂ , which separates the changeover contacts of the relay IR ₂ from the ring transmitter RU ₂ and apply it to an AC power source. So come on ringing alternating RC ₂ in the pipeline F _2nd

The pull-in delay of R ₂ of more than Vio seconds means that it is not excited by the electromechanical surges. The one

occasional direct current surges before the onset of the ringing current must be suppressed in the receiving office so as not to influence the voters.
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B. By switching the line through.

i. Temporary connection while dialing.

ίο Fig. 4 shows the parts of the end office required to understand the invention and a repeater circuit in the line. If the plug of the telegraph is inserted into the jack on the jack to initiate a connection, a working contact on the jack closes the current path for the call relay RR ₂ . Its changeover contacts separate the long-distance line from the jack and connect it to the ringing power source of the long-distance exchange. An additional normally open contact creates a current path for the relay VR, which is provided with a pull-in delay, which after a short time disconnects the excitation circuit for RR ₂ and creates a stopping path via the normally open contact of the pawl. VR therefore remains excited until the remote cord plug is pulled out of the jack after the conversation has ended.

A ringing current has reached the long-distance line for a period of time determined by the ON delay of the relay VR. This flows in the first intermediate amplifier circuit via two changeover contacts of the changeover relay UR ₁ , the ring transformer RU ₁ and the normally closed contacts of the relay R ₁ . It excites the AC relay Rf ₁ , which is located in the bridge, whose normally open contact creates a current path for the relay R _2. This is connected via the following current path: grounded battery, R ₂ , own holding contact, normally closed contact 4 from the changeover relay UR ₂ , normally closed contact from UR ₁ and ground. The changeover contacts of R ₂ separate the ring transformer RU ₂ from the amplifier circuit and connect it to the AC power source of the amplifier office. Ringing current reaches the outgoing trunk line via RU ₂ and two other changeover contacts from UR _1. Due to the binding of R _2, its duration is independent of the duration of the incoming ringing current. Additional working contacts of the relays R ₁ and R _z short-circuit the inputs of the amplifier circuit V in order to prevent whistling which would otherwise occur due to a disturbance of the equilibrium of the compensation circuit.

A working contact excites the switch relay UR ₁ , which is provided with a pick-up delay . UR _{1 changes} its contacts after a short time, binds itself to UR ₁ via the normally closed contact 3, disconnects the holding circuit for R ₂ and changes its four changeover contacts. As a result, the two branches of the long-distance line are connected to one another by bypassing the amplifier V via inductors.

The process is repeated in the following intermediate amplifiers, due to the ringing current transmission of a certain duration sent by means of R ₂ from the previous office, until all amplifiers are switched off from the trunk line.

Now the dialing current impulses (direct current impulses) are sent over the long-distance line in the end office by means of the dial NS and set the voter in the receiving office. After successful dialing, the call relay RR ₁ automatically connects the call current source of the dialing office to the connected trunk line. In the first repeater Office, the AC relay RF '\ addresses whose work contact creates a current path for the provided with energizing delay Umschalterelais! 7.R ₂ whose contacts be folded in the direction indicated by the numbering sequence. The pick-up delay is already provided for contact 1 so that the selection jolts, which can cause the 2? / Relays to respond for a moment, do not affect the UR _{2 relay.} The purpose of the chokes between Rf ₁ and .RjF _{2 is} that the call energy arriving from the left or right benefits the relevant relay as much as possible and makes it respond.

After the response of UR ₂ , its contact 1 closes first and creates a holding circuit for the relay via its npch non-relocated normally closed contact 5. A moment later, contact 2 disconnects the previously mentioned excitation circuit for UR ₁ , then contact 3 the holding circuit of this Relay. The dropping changeover contacts of UR ₁ switch the amplifier V back into the connection. The ringing current transmission from the end office has not yet stopped at this point in time, so that, as described earlier, R ₂ responds, binds itself via the not yet dropped normally closed contact 4 of UR ₂ and the normally closed contact of UR ₁ , which has now fallen back again, and calls again sends from the repeater office to the further long-distance line. UR ₁ cannot be re-energized as a result, since the normally closed contact 2 of UR ₂ has already been opened. Shortly thereafter, the normally closed contact 4 of this relay separates the holding circuit of R ₂ , whereby the duration of the call in the further long-distance line is limited to the required amount. Finally, the normally closed contact S separates UR _2's holding circuit

so that all relays are returned to their rest position and the amplifier is ready to talk is turned on in the connection.

The same processes are repeated in the following booster offices, due to the ringing current transmission by means of R _{2 of} the previous office.

2. Temporarily switch on the amplifiers after dialing.

Fig. S shows the parts of the end office necessary for understanding the invention and an intermediate amplifier in the line. In the idle state, as explained later, the relay R in the end office is energized via its holding contact and the normally closed contact on the trunk line jack. So prevent

ao changes his shifted normally closed contact the response of the call relay RR ₁₁ via the normally closed contact of the latch. If the plug of the remote cord is inserted into the jack to initiate a connection, the holding circuit for R is disconnected. RR ₂ does not respond, however, because its excitation circuit is now open in the normally closed contact of the latch.

The broadcast of the. Dialing current surges (direct current surges) by means of the number disk NS via the long-distance line that is switched through in the idle state, as can be seen in the figure. After successful dialing, the call relay RR ₁ automatically connects the call current source of the remote exchange to the line for a short time. The ringing current reaches the first intermediate amplifier office via two changeover contacts of the changeover relay UR ₁ into the alternating current relay Rf ₁ , whose normally open contact creates _{a circuit for UR 1.} UR ₁ is provided with a pull-in delay so that it is not influenced by the selection current surges which Rf ₁ could excite for a moment. The chokes between Rf ₁ and. The purpose of Rf _{2 is} that the ringing current arriving from the left and right is of full benefit to them.

UR ₁ binds itself via the normally closed contact 3 of UR ₂ and changes its changeover contacts, as a result of which the amplifier V is switched into the connection.

At this point in time the ringer current transmission from the end office has not yet stopped; the ringing current passes via the ring transmitter RU ₁ and the changeover contacts of the Weiterrufrelais R ₁ in the opposite bridge in AC relays Rf. ₁ Its normally open contact creates a circuit for the relay R ₂₁ which is linked via normally closed contact 1 of UR ₂ . Its changeover contacts separate the ring transmitter RO ₂ from the amplifier circuit and connect it to the ringing current source of the amplifier office, so that via RU ₂ . and the relocated changeover contacts of UR ₁ Rufstrom are sent to the further long-distance line. The binding of R ₂ makes the duration of this ringing stream independent of that of the incoming ringing stream.

Another normally open contact of R ₂ short-circuits the amplifier input to prevent whistling. A last contact closes a circuit for the switchover relay UR ₂ , which is provided with a pick-up delay, the contacts of which are switched in the order indicated by the numbers. After a short time, contact 1 disconnects the holding circuit from R ₂ . The alternating current feed into the further transmission line ceases and UR ₂ drops out before it has switched its contacts 2 and 3.

In the next repeater office, the process is repeated, due to the ringing current transmission of a certain length of time by means of R _{2 of} the previous office, until all amplifiers are switched on in the connection and the connection is thus made able to speak.

When the conversation is over, the clerk pulls the cord plug out of the telephone jack. This energizes the call relay RR ₂ , disconnects the long-distance line from the jack and connects it to the AC power source of the end office. A normally open contact of RR ₂ creates a current path for the relay R, which is provided with a pull-in delay, which after some time forms a stopping path via the normally closed contact of the latch and disconnects the circuit for RR ₂ . A call of a certain duration reaches the long-distance line, which exceeds that of the call current transmission after a successful dialing. This ringing current arrives in the first amplifier office, as described earlier, via the shifted changeover contacts from UR ₁ to the relay Rf ₁ , which energizes the relay R ₂ , which again sends ringing current from the amplifier office to the long-distance trunk line. As before, UR ₂ responds after a short time, whose contact 1 first disconnects the holding circuit for i? 2. Since in this case, however, the ringing current from the end office continues at this point in time, R ₂ and UR ₂ do not drop, but UR _{2 first} creates a holding circuit via the closing normally open contact 2 and the still closed normally closed contact 3. With the cessation of the ringing current transmission from the end office, R ₂ drops out and terminates the forwarding of ringing current. Finally, contact 3 of UR _{2 separates} the holding circuits of UR ₂ and UR ₁ , so that all relays return to the rest position and the two long-distance line branches are switched through again.

In the next offices, the processes are repeated, due to the long ringing currents by means of R ₂ from the previous - previous office,
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C. Via simultaneous telegraphic channels.

ι. 2 selector current paths per quad. .

Fig. 6 shows the 3 intermediate amplifiers a four-way telephone, as far as it is · necessary for an understanding of the invention is. Simultaneously over the two, veins of the

Long-distance line F ₁ I incoming equal current surges flow through the two primary winding halves of the ring transformer RU ₁ 1 in counter-connection, the one primary winding half of the four-ring transformer RU ₁ III, the like of RU ₂ III and arrive via the two primary winding halves of RU ₂ I in counter-circuit simultaneously the two cores of the long- distance line F ₂ I. The same applies to route F ₁ II to F ₂ II.

2. 4 selector current paths per quad.

Fig. 7 shows the three repeaters of a four-way telephone, as far as is necessary for an understanding of the invention. Via a wire of the long- _{distance line F 1} I incoming dialing direct current surges flow through a primary winding half of the ring transformer RÜ _r I and reach earth via the changeover contact of the transmission relay R ₂ and the winding from R _1. R ₁ separates the corresponding wire of the long-distance line F ₂ I from the associated transmission relay R _z and applies it to a DC voltage source in the amplifier office. So enters a corresponding direct current pulse via a primary winding half RU ₂ 1 into the vein of R _2. 1

The same applies to the second wire from F ₁ I ₁ F, I and the two wires from F ₁ II, F. IL "-

Claims (7)

Patent claims: 1. Circuit arrangement ■ for telephone systems with intermediate amplifiers, characterized in that suitable switching devices, in particular relays (R ₁ ...), Are provided in the intermediate amplifier offices, with the help of which the dialing current surges through the amplifier or bypassing the amplifier, the setting of the dialing devices in Cause end office. 2. Circuit arrangement according to • Proverb 'i, characterized in that the ■ · Adjustment of the voters in the final office with the help of one by the given power surges modulated carrier frequency is effected. 3 ·. Circuit arrangement according to Claim i, characterized in that through the one on the grid of the first amplifier, in the form of an induction surge 'incoming direct current surge is one in the anode circuit of the amplifier " • The receiving relay is actuated, which causes the excitation of a pulse relay, by which direct voltage of the required level is applied to the following transmission line section. to propagate the DC impulse to the nearest amplifier. 4. A circuit arrangement according to claim 2, characterized in that an audio frequency is controlled by the direct current surges, which goes through the amplifier on the line and is rectified on the receiving side by means of a shotgun to operate a receiving relay located in the anode circuit of the tube, through which a in one Local circuit relay (HR in Fig. 2) for the selector drive is controlled. 5. Circuit arrangement according to claim "2, characterized in that a carrier frequency through alternating currents controlled in the rhythm of the currents frequency modulated by call and after passing through the line and amplifier in a known manner in dialing current surges 'is converted back. 6. A circuit arrangement according to claim i, characterized in that, _Λ while dialing the trunk line is temporarily switched through, bypassing the amplifier xoo, or is continuously switched through while the amplifier is only switched on temporarily for the duration of the voice connection. 7. Circuit arrangement according to claim 1, 3, 4 or 5, characterized in that the dialing current pulses arriving at the receiving side are used to actuate a sensitive relay (e.g. no R ₁ in Fig. R), through which a surge relay ( JR ₂ ) is controlled, and that the fall of one of the two relays is delayed so that current surges of the same duration as the original go to the receiving device. 1 sheet of drawings. .