DE704076C - Circuit arrangement for telephone systems with dialer operation - Google Patents

Description

Circuit arrangement for telephone systems with dialer operation The invention relates to a circuit arrangement for telephone systems with dialer operation, at which the sequence of the number switch provided for sending out the number current impulses is dominated at the participant points by an inhibition (escapement), which is controlled by a current impulse transmitter arranged in the office is inevitably controlled.

The advantage of this arrangement is known to be that a safe and uniform, independent of the length of the respectively connected subscriber line Current impulse is achieved. Only the known arrangements of this type have the Disadvantage that they: either a special battery at the subscriber station or when moving the battery to the office, at least the connection of earth potential at the subscriber station require what for operational and economic reasons is undesirable.

This disadvantage is eliminated according to the invention in that for the Duration of a number dialing (setting and rewinding the dial) depends on the Number switch in series with the one that controls the step-by-step return of the number disc Relay at the subscriber station a direct current of a certain direction blocking switching means connected in a bridge between the line cores and by a after setting the Number switch of the calling subscriber transmitted identifier switching means be brought into effect in the office, indicating the direction of the subscriber line reverse the pouring supply current and a surge circuit for the bridge relay form.

The accompanying figure shows an exemplary embodiment of the invention. The details which are not essential for an understanding of the invention are omitted from the figure. The mode of operation of the arrangement is as follows: If subscriber N wants a connection with another subscriber, he picks up his handset and closes the hook switch contact HU. In this case, an incentive circuit for the first preselector I. VW is closed in a known manner via the closed subscriber loop. The selection starts up and searches for a free first group selector 1st GW in a free choice. If he has found one, the following circuit for the test relay T of the first preselector and the relays A and G of the first group selector is closed: Earth, battery, winding of relay T, wire c, contacts 5a, 4c, winding II of the relay A, winding I of relay G, head contact ko, earth. The relay T of the first preselector stops the preselector in a known manner, switches the speech wires to the first group selector through disconnection of the call relay and blocks the occupied line against other occupancy. However, these switching operations are not shown in the figure.

In the first group selector I. GW, the relay A excited via its winding II removes the short circuit for the occupancy relay C by opening the contacts i a and 5 a. Relay C then responds in series with relays A and G. By opening contacts: 1 c and 6 c, it interrupts the original excitation circuit of relays A and G and is maintained via contact 3 c. After the original excitation circuit has been interrupted, relay A remains in the following circuit via the subscriber loop: earth, choke coil Dr, contact i 7 g, lower voice wire b, induction winding Tr, microphone M, contact FK or parallel contact nsal, hook switch contact HU, upper one Voice wire a, contact 14 9, winding I of relay A, battery, earth. The relay G is held in the following circuit: earth, contact 7 a, winding II of relay G, battery, earth. After energizing relay C, the following circuit for delay relay V is also formed in the first group selector: earth, contacts 2o c, i 9 / r, winding of relay V, battery, earth.

The participant now begins to dial the number; he pulls out his dial to send out the first row of jerks to set the first group selector 1st GW. As soon as the dial leaves the rest position, the contact jtsal is opened and contact nsa2 is closed in a known manner. This contact remains closed until the number switch has reached the rest position after the number disc has finished running. The number switch of this subscriber station is not designed in the usual way so that when the dial is running, a current impulse contact alternately opens and closes the subscriber loop according to the selected digit, but the sequence of the dial is controlled by an escapement controlled by the magnet W. . The start of dialing the number is marked by the finger contact F1 (. This is opened when the participant touches the limit stop provided in the usual way while lifting the dial. After releasing the dial, contact F1 (is no longer closed, but remains opened by a mechanical lock, which can be carried out in any way, until the number switch has returned to the rest position. It is now assumed that the subscriber has dialed the first digit and opened the finger contact F1 (. This opens the circuit for the relay A interrupted via the subscriber loop; the relay A cannot hold itself via the contact izsa_, and the magnet W, since the rectifier G1, which according to the invention is in series with the magnet W, is polarized in such a way that the current flow for the relay A is blocked Relay A in the first group selector therefore drops out and closes afterwards en circuit for relay H: earth, contacts izc, iik, ioa, winding of relay H, battery, earth. Since after the fall of the relay A on the contact 7a and the retaining circuit for the relay G is interrupted immediately and this relay comes to drop, so the relay H of the following circuit for the relay I (formed after excitation: earth, winding I of the relay K, contacts 1 5 h, 1 3 g, upper voice wire a, hook switch contact HU, contact nsa2, rectifier Gl, magnet W, lower voice wire b, contacts 1 6 g, 1 8 h, winding II of relay K, battery, earth. The direction of the current and the polarity of the rectifier GL ari of the subscriber station N are such that a sufficiently large current is created in this circuit. The relay, K and the magnet W respond. I The magnet W is the locking wheel of the dial so far free that the dial is moved back by one step by means of a spring force. Relay I (opens the circuit of relay H through its contact ii k, so that it falls again. The delay relay V, whose circuit at contact 1 9 h temporarily opened, does not fall during the transmission of the number current impulses, which is controlled by the relays H and K. While the relay I (is energized, the following circuit for the lifting magnet Hb of the first group selector is closed: earth, lifting magnet Hb, contact 24 lt, battery, earth. the following circuit for the delay relay E : earth, contact 23 k, winding of delay relay E, battery, earth. Relay E responds and remains independent of contact 23 k via earth, contacts 22 v, 2 ie, winding of relay E, Battery, earth.

The relay H, which is brought to waste by opening the contact iik, in turn interrupts the loop circuit running via relay I (and magnet W (at the subscriber station) at contacts 1 5 1a and i B lt . Relay I (and magnet W come to their = After the relay I (has dropped out, the circuit for relay H is closed at contact iik. Relay H responds and in turn closes the circuit for relay I (and magnet W, which then also respond again . Magnet W at the subscriber station causes the number disc to be reset by a further step, while relay I (in the first group selector uses contact 24 k to transmit another current impulse to the lifting magnet Hb . This game is repeated until the number disc is in the rest position The number disc is advanced by as many steps as corresponds to the number set. Relay I (an equal number of current surges on the lifting magnet Hb..

If the dial has reached the rest position, first the contact ttsa2 is opened and the contact ttsal is closed. However, since the subscriber loop at contact F1 (, which closes a little later, is still open, relay I (no longer responds via the subscriber loop. Relay H in the first group selector remains energized for a longer time due to the closed contact iik the contact 19 h is open so long that now the delay relay V also drops. After the relay V has dropped, the relay G is again energized in the following circuits: earth, contacts 9 v, 8 h, winding II of the relay G, Battery, earth. After relay V has dropped out, the holding circuit of relay E is opened at contact 22 v, which drops out with a delay. After relay G has responded, relay A is excited via the subscriber loop, after which the finger contact FI (at the subscriber station is now also closed is: earth, choke coil Dr, contact 17g, wire b, induction coil TY, microphone M , finger contact FK, hook switch contact HU, wire a, contact 14 g, winding I of relay A, battery, Earth. The relay A responds and opens the circuit for the relay H at the contact io, a, so that this comes to waste. Relay G is held independently of contact 8 la via contact 7 a. After relay H has dropped out, delay relay V also responds again via contact 19 h. The switching status as it was before the start of dialing is restored.

When the next series of current impulses is transmitted, which is initiated, when the participant opens his dial for the second time, they play each other the same switching operations. Since the first group voter is now on one has set free subsequent number surge receiver, the transfer takes place the number current impulses on this in the first group selector 'by connecting Earth via contacts 26 c; 25 k to the upper speech artery. The feeding of the calling Subscriber station N takes place in the usual manner via the winding I of the relay A and the feed bridge containing the throttle Dr.

The connection is released when the calling subscriber hangs up his receiver. This interrupts the subscriber loop at the hook switch HU. In the first group selector relay A comes to waste. Relay H responds again via ontakt ioa. ' At contact 7 a the circuit - for relay G is interrupted and this relay is brought to waste. Relay H interrupts the circuit of the delay relay V. After relay V has dropped out, the occupancy relay C is short-circuited via contacts 2 v, i a, 27 e and made to drop out. After relay C drops out, the circuit of relay H is interrupted at contact i 2 c. The relay drops out. Since in the meantime the group voter has also been brought to the rest position in some known way, with the head contact ko being closed again, all parts of the voter are triggered and ready for a new assignment.

Claims (7)

PATENT CLAIMS: i. Circuit arrangement for telephone systems with dialer operation, in which the sequence of the number switch at the subscriber stations is controlled by an inevitable impulse transmitter arranged in the office, characterized in that for the duration of a number dialing (setting and rewinding the number disc) depending on the number switch (via contact nsa2) in series with the relay (bridge relay W) that controls the gradual return of the dial, a direct current of a certain direction (e.g. to b-, - to a-wire) blocking switching means (Gl) is connected in a bridge between the line wires at the subscriber station and switching means (A, G, H) in the office which reverse the direction of the feed current flowing over the subscriber line and form a surge circuit for the bridge relay (W) are activated by a code transmitted after the number switch of the calling subscriber has been set. 2. Circuit arrangement according to claim i, characterized in that an interruption of the existing supply circuit when dialing the number by switching the speech wires to the rectifier (G1) using the from the Idle position of the number switch dependent contact (nsai, nsa2) prepared and finally by a further contact lying parallel to this contact (F9) which, after the windscreen has been lifted, depending on the lift limiting fingers. stop is actuated, is completed. 3. Circuit arrangement according to claim 2, characterized in that both the number disc contact (nsal, nsa2) as well as the finger contact (FK) after the dial has returned to its rest position be brought back to their original position, but the latter (FK) with a time lag compared to the former (nsa). q .. Circuit arrangement according to Claim 2, characterized in that when the feed circuit is interrupted Dropping feed bridge relay (A) in the office of the starting relay (H) of a relay breaker switches on, which reverses the supply current on the speech wires and thereby the Number surge circuit closes. 5. Circuit arrangement according to arrival q demanding., Characterized in that the number rush current circuit in series with the rectifier (GI) and the bridge relay (W) to the subscriber station in the Official a second relay (K) of the relay interrupter which to pass on the number surges serves to subordinate voters. ' 6. Circuit arrangement according to claim q. and 5, characterized in that the relays (H, K) of the relay interrupter control auxiliary relays (G, Y, E ) which ensure the disconnection of the feed bridge (A, Dr) from the subscriber loop during the duration of the number current impulse. 7. Circuit arrangement according to claim 3 and q., Characterized in that that the finger contact (FK) after return of the dial in the rest position Keeps the microphone supply circuit open until the starter relay (H) of the relay interrupter Switching the subscriber line in the exchange from the number surge circuit to the supply surge circuit has brought about.