US1795339A - Circuit arrangement for automatic telephone systems - Google Patents

Description

March 10, 1931. M. LANGER 1,

cmcux'r ARRANGEMENT FOR AUTOMATIC TELEPHONE SYSTEMS Filed Aug. 12, 1927 Im ren u1" Flax L er' to 04 are operated.

Patented Mar. 10, 1931 UNITED s r MAX LANGER, or HEB-Mellow", NEAR- BERLIN, GERMANY; Assrcnon TO SIEMENS &

I-IALSKE AKTIENGESELLSCHAFT, OF WERNERWEBK, SIE MENSSTADT, NEAR BER- LIN, GERMANY CIRCUIT ARRANGEMENT FOB AUTOMATIC TELEPHONE SYSTEMS Application filed. August 12, 1827, Serial No.

In automatic telephone systems a certain and faultless emission of current impulses is dependent to a large extent on the switching times of the impulse-storing relay. Known already are arrangements in which the impulse storing relay is connected in a more sensitive circuit during the sending out of impulses. With such arrangements however one of the switching periods of the relay is unfavorably influenced.

The purpose of the invention is to bring about that with each condition of energization of the relay the switching time necessary for obtaining the other condition of energization shall be curtailed and this is accomplished by the impulse-storing relayso acting upon, its own circuit that with each state of energization (either energized or deenergized) there is present a condition of-current which is adapted to bring about a rapid attainment of the other condition ofener- 'gization.

The drawing shows an example ofthe invention inthe form of the circuit of a group selector. Assuming that the group selector has been engaged by any switching device allotted to it, then the relay 0 will be energized. Consequently the contacts 01 The contact 01 connects the winding II of the relay G to the 0 wire. The contact 02 applies earth to the circuit for the lifting magnet H. The latter however is not energized because, during the en-' gagement of the group selector the line relay A and the release relay B at the lines a and b are energized. The energizingcircuit for the relays A and B runs from battery, winding of the relay A, a-wire, over the preselecting member (not shown), subscribers loop to the 7) wire, winding Tl of the relay B, contact a2, of the relay B, earth. The relay B through its contact 61 opens the short circuit of the winding 11 of the relay C. Relay A opens, through its contact (11 the circuit for the lifting magnet H. If, by using his dial switch, a subscriber sends out a series of impulses, then during a first interruption of the loop the relay A will be made to retract; since the contact a2 is open when the relay A is energized, the latter rap- 212,456, and in Germany January 31, 1927.

such a kind that the relay A responds con-' siderably more rapidly than if the winding I of the relay B were not short circuited. During the energization of the lifting magnet H the relay V is maintained energized over its winding II, theshort circuit around its winding I rendering relay V slow-acting,

wherebythe circuit of the rotary magnet D is maintained opened through the contact o1. If the switching arms of the group selector are positioned on the desired tens level, the relays Aand B are energized at the end of the impulse sending so that the relay V is made to retract. During the first lifting step of the selector the closing of the oil-normal contact 701 took place, so that the following circuit is completed for the rotary magnet D during the retraction of the relay V after theimpulse series has been sent out by the subscriber: earth contact J01, contact p1, leftcontact of the double acting contact o1, winding of the rotary magnet D,- battery. The rotary magnet D is energized and actuates its contact cl, whereby an ener-. gizingcircuit is established for the relay V a which runs from the battery over the wind-* ing of the liftingmagnet H. winding of thc relay V, closed 03 contact, off-normal contact 731, earth. Since, duringthe first rotary step of the selector, the contact '10 had been opened,

the resistance of the relay V in relation to the resistance of the winding of the lifting magnet H is of such a kind that the lifting magnet H is not energized in this circuit. By

energizing the relay V the double acting contact '01 is opened. and thus the circuit'for the rotary magnet D is interrupted. The rotary magnet'D is de-energized and through its contact cl opens the circuit for the relay V. The latter, upon retracting, closes the contact 01 whereby the circuit for the magnet D is again closed. This alternate action between the relay V and the magnet D is continued until the testing arm of the selector has found a free line. If the testing arm finds battery over the outgoing line 0 the relay P is made to energize and opens the circuit for the rotary magnet I) through its contact p1. The contact 72?. applies earth to the winding I of the relay P. The contacts p3 and p 1 switch the connection through.

If the connection is to be released the calling subscriber hangs up his receiver whereby the relays A and B are made to retract. The relay A closes the contact a2 and thereby again establishes the current conditions adapted to cause the relay A to function. Through its contact 51 the release relay B short circuits the winding II of the relay C so that the latter is made to retract as the off-normal contact 702 has already cut oil tl e winding I of the relay C from earth, during the first lifting step of the selector. 'lhrough contact 04 the winding of the relay P1 is short circuited so that the latter is de-energized. Consequently contact p1 is closed and the rotary magnet is energized over earth, contact 701, contact 791, left contact at the double acting contact 111, winding D of the rotary magnet, battery. The rotary magnet now moves a step and actuates its contact (Z whereby a circuit for the relay V is completed over: earth, off-normal contact 7.:1, double back contact (I, windings I and II of the relay V, winding H of the lifting magnet H, battery, earth. In this circuit the lifting magnet- H does not respond. However, the relay V is energized and actuates its contact o1 whereby the double acting contact is opened and the retary magnet D is made to de-energize. Thus, in this manner, the switching arms of the group selector are rotated until they reach their extreme rotary position, thereby causing the switch to release in known manner and open contact 721 and close contact 702. Through the retraction of the relay P the switching devices which have been taken into use by the selector GVV are released in any known manner.

hat is claimed is:

1. In a telephone system, an impulse responding relay, a release relay, a circuit for said relays including a source of current, means for interrupting said circuit to deenergize and energize said impulse responding relay, and means controlled by said impulse responding relay in either its onergized or deenergized positions for chang ing the said circuit so as to enable said impulse responding relay to rapidly attain its energized or deenergized position as the case may be, said means being-effective also to render said release relay slow acting.

2. In a telephone system, an impulse "respending relay, asecond 'rel'ay having two windings, a trunk line, a battery for talking and operating purposes, an energizing circuit for said relays including one pole of battery, the winding of said impulse relay, the two sides of said trunk line, one winding of said second relay, and the opposite pole of battery in series, and contacts on said impulse relay operated responsive to the energization of said impulse relay for including the second winding of said second relay in said energizing circuit to reduce the current flow in said circuit to enable said impulse relay to more rapidly deenergize when said circuit is opened.

3. In a telephone system, a two conductor subscribers line extending to an automate switch, a battery,a line relay in said switch connected between one conductor of said line and one pole of said battery, an impedance in said switch connected between the other conductor of said line and the other pole of said battery, a circuit for shunting said impedance, and contacts on said line relay included in said circuit.

I. In a telephone system, a two conductor subscribers line extending to an automatic switch, a battery, a line relay connected between one conductor of said line and one pole of said battery, a double wound relay connected between the other conductor of said line and the other pole of said battery, one winding of said double wound relay being normally short-circuited, and contacts on said line relay for opening the short-circuit around said winding to increase the impedance of said double wound relay when said line relay is energized.

In witness whereof, I hereunto subscribe my name this 19th day of July, A. D. 1927.

MAX LANGER.

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