DE611492C - Circuit arrangement for workplaces in telephone systems - Google Patents

Description

GERMAN EMPIRE

ISSUED ON
MARCH 29, 1935

REICH PATENT OFFICE

PATENT LETTERING

CLASS 2Ta ³ GROUP 5

Siemens & Halske Akt.-Ges, in Berlm-Siemerisstadt *) Circuit arrangement for workplaces in telephone systems

Patented in the German Empire on March 9, 1927

The invention relates to a circuit arrangement for workplaces in telephone systems where a calling station occupies a line via a voter, via which a job is achieved.

With such systems it can happen that the calling station after sending the power surges for setting the voters on a line leading to the workplace and after switching on the workplace sends out more power surges for some reason. In that case they would there are annoying cracking noises in the officer's receiver. There are now plants known, in which this inconvenience is avoided in that when sending out Power surges on the part of the calling station after setting the selector switching means on Workplace come into effect, which has a disruptive influence on the speaking apparatus impede. But if power surges are sent out after the voters have set, the switching means, which is supposed to prevent a disruptive influence on the officer's speech apparatus, but not yet for Effect has come, then there will still be cracking noises in the officer's receiver.

The invention now aims to avoid this disadvantage, which is achieved thereby that auxiliary devices are provided which prevent the speech device from being used Officer is adversely affected by current surges when they are switched on, before further actuated by these power surges, known anti-shock devices have become effective.

The invention is shown in the drawing. All that are immaterial for the invention Parts are left out.

It is assumed that the subscriber, after setting the group selector GW to a specific row of contacts, reaches a line leading to a workstation, to which the officer's speech set is connected by means of the call finder AS . When the group selector GW is set to the connecting line O ₁ , B ₁ , C ₁ , relay C _{1 is} excited via the lowest arm of the group selector. Contact 1 C ₁ is closed and closes a circuit for the on relay via: earth, contact Ic ₁ , contact 2 1, relay on, battery and earth. Relay An energizes relay X via contact 4 an . Relay X is a delay relay that short-circuits the officer's receiver T via contact 17 χ.

By relay ^ «the rotary magnet D is excited via earth, contact 22 d, contact 6 p, contact 3 on, rotary magnet D, battery, earth. The call seeker AS is switched one step further. Since the circuit of the

* ") The patent seeker stated as the inventor:

Alfred Scheunert in Berlin-Siemensstadt.

Rotary magnet D is alternately excited and de-excited by the self-breaker contact 22 d, the call seeker is switched on until the switch arms of the call seeker have reached the line marked by the closed contact 7C _1. When connecting to this line, the following test circuit is established: Earth, contact 5 on, ReIaIsP ₁ , c ₂ arm of caller AS, contact 19 1, contact Jc ₁ , winding II of relay T, battery, earth. The relays P ₁ and T respond. Relay P ₁ is held via contact 8 P ₁ . Relay P ₁ closes its contacts Qp ₁ and IQp ₁ , whereby the officer's speech set is applied to the connection line selected by the group selector GW. The relay T opens its contact igt and keeps the occupied line blocked by closing the contact 20 1. Relay T interrupts the circuit of relay An at contact 2 1 , so that relay An drops out and breaks the circuit of relay X by opening contact 4. The relay X is therefore still energized for a short time after the connection to the contacts gp _x and 1Op ₁ , so that if further current impulses are sent by the calling subscriber after the connection to the contacts gp _x and 10 ^ _1, a disruptive influence on the speech apparatus of the Officer is prevented by short-circuiting the receiver via contact ijx .

If the calling subscriber sends out further current impulses after the group selector has been set, relays A and B in the group selector GW are made to drop with each loop interruption. When relay A drops out for the first time, closing contact 11 α relay V via +0 causes contact 23 c to respond, which by moving contact 14 puts the battery on the i> ~ wire. Since the call seeker AS is set and thus the connection to the contacts gp _x and 1Op _{1 has taken} place, the following circuit for the relay B ₁ at the officer's workstation is closed: earth, battery, contact 14.V, contact 15 p, switching arm des Group selector, switching arm b _{% of} the caller AS, contact 1Op ₁ , relay B ₁ , earth. Relay B ₁ opens its contact 18 Zf ₁ , so that the loop to the officer's voice set is interrupted. After the current impulses have expired, relay V also drops out, puts contact 14U back, so that relay B _{1 is} de-energized, and the officer can now communicate with the calling party. As can be seen from the above, the relay X prevents the intercom of the officer from being adversely affected by the incoming current when the officer is switched on before the further interference protection device actuated by the current surges, namely the relay B ₁ , has become effective.

In the exemplary embodiment described above, the officer's headset becomes ineffective during the time the call searcher is switched on and a short time thereafter by short-circuiting the handset. However, the entire headset could also be rendered ineffective by short-circuiting the speech lines. Likewise, instead of disconnecting the line at contact 1So ₁ when power surges are emitted, after setting the group selector to the selected connection line, the handset or the headset can be short-circuited. In this case, the contact of relay B _{1 would be} parallel to contact 17 χ .

Claims (2)

Patent claims: i. Circuit arrangement for workplaces in telephone systems, which can be reached via voters with free choice, to prevent the interfering influence of the officer's speech apparatus by current surges when the device is switched on, characterized in that auxiliary devices (X) preventing the device from being influenced at the workplace by the starting device ( An) of the selector before other known safety devices (B ₁ ) triggered by these current surges take effect. 2. Circuit arrangement according to claim i, characterized in that a delay relay is switched on by the starting device (An) , which short-circuits the receiver of the speech set. 1 sheet of drawings