US2096029A

US2096029A - Signaling system

Info

Publication number: US2096029A
Authority: US
Inventors: Cesareo Orfeo; Mueller Robert
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1936-12-18
Filing date: 1936-12-18
Publication date: 1937-10-19
Anticipated expiration: 1954-10-19

Description

Oct. 19, 1937. Q CESARE() 'Er AL 2,096,029

SIGNALING SYSTEM Filed Deo. 18I 1936 l0 /4 4- A A M Poumzeo A!" O` CESAREO /Nl/.EA/Tons R MUEL L ER A TTORNE Y Patented 19, 1937 UNITED STATES PATENT OFFICE srcNsLrNc srs'rrznr New York Application December 18, 1936, Serial No. 116,528

8 Claims.

This invention relates to a system for producing and controlling the frequency of electrical impulses.

In the signaling art and particularly in circuits for testing the functioning of the circuits of telephone systems it is often desirable to produce impulses accurately timed as to their closed and open periods. It is therefore the object of the present invention to provide circuit facilities, simple in construction and reliable in operation, whereby impulses may be generated at any desired speed and having any desired ratio between their closed and open periods.

'I'he impulse generator in accordance with the present invention is of particular utility in producing impulses, simulating those generated by the usual subscrlbers dial, for testing the originating senders of telephone exchange systems which normally respond to impulse series dialed by subscribers to register the designations of wanted lines and to control the establishment of connections. It is to be understood, however, that the invention is not limited to such specific use, but has the more general utility of generat- 25 ing impulses of determined characteristics.

'I'he impulse generator comprises two differentially wound polarized relays which mutually control each other, a condenser associated with each relay and adjustable resistances associated 3- with the circuits extending through the windings of the relays. One of the relays has its first or operating winding connected between ground and a source of battery potential through one of the adjustable resistances and its second or control winding connected between ground and the source of battery potential through a condenser and a second of the adjustable resistances. The

second of the re1ays has its nrstoeritir o start relay for applying operating ground to the impulse generator and a' start -key are also provided. 'Ihe second relay also upon each operation thereof closes over its front contact a work circuit to which impulses generated by the interaction of the two relays are to be applied.

Havinanowdescribedinageneralmannerthe association of apparatus comprising the improved impulse generator of this invention, it is believed that a clearer comprehension thereof and of the manner in which it functions may be had by referring to the following detailed description taken in connection with the accompanying drawing.

'I'he impulse generator has been disclosed in connection with the dial pulsing circuit of an originating or subscribers sender test circuit, only relays I and 2 of which having been disclosed. These relays are both polarized, relay I controlling the transmission of impulses to the sender under test and relay 2 controlling the operation of counting relays to count the impulses transmitted in each series in accordance with the setting of digit keys in the sender test circuit. Inasmuch as the invention is not concerned particularly with the functioning of relays I and 2, it will be suilicient to say that these relays follow the impulses generated by the impulse generator.

When the impulse generator is to be conditioned to generate impulses, ground is connected to conductors 3 and I in any desired manner as by the operation of start relay 5. With ground connected to conductor I a circuit is established therefrom through resistance 6 and thence by parallel paths through resistance 'I to battery and ground and through the windings of polarized relays 2 and I and resistance 8 in series to battery and ground, but the current flowing through the windings of relays I and 2 is not in such a direction as to cause their operation. With ground connected to conductor 3, a discharge path for condenser 9 is effective from conductor 3 through the lower or control winding of polarized relay I to ground at the back contact of polarized relay II and condenser 9 immediately discharges. VCondenser I2 is at the time in a discharged condition since a discharge path therefor is completed over the back contact of relay I0 and through resistance I3.

When ground is connected to conductor 3, operating circuits for both relays II) and I I are also established, the circuit for relay III extending from ground on conductor 3, through the upper or operating winding of relay III and through adjustable resistance Il to battery and ground and the circuit for relay I I extending from ground on conductor 3, through the lower or operating winding of relay II and through adjustable resistance I to battery and ground. Relays Il and II now both operate, but relay III immediately releases as soon as relay II operates and removes ground poof relay lil and adjustable resistance id, since charging current now flows through the lower Winding of relay l@ over a path from ground on conductor 3, through condenser 9, the lower winding of relay i0, adjustable resistance le to battery and ground in a direction to overcome the energizing eiect of current owing through the upper winding of relay iu. However, as soon as the surge of charging current dies out, the upper winding of relay lil takes control and relay l@ reoperates.

With relay H operated ground is connected over its front contact to a point between resistance 8 and the windings of relays i and 2 whereupon these relays now receive current in the proper direction through their windings to cause their operation. Pulsing relay l upon operating now closes the pulsing circuit over conductors i8 and l@ and counting relay 2 prepares a circuit over conductor 20 for counting the impulses.

To start pulsing the key 2 I is operated and, with relay I0 operated, a charging circuit for condenser i2 is established from ground over the contacts of key 2l, the front contact of relay I0, through condenser i2, the upper or control winding of relay H and through adjustable resistance ll to battery and ground. Since the windings of relay il are differentially wound, relay il releases while current is iiowing through its upper winding to charge condenser i2. The capacitance of condenser l2 and the resistance of resistance element il may be suitably adjusted to control the period during which relay Il remains released and, since upon the release of relay il, relays i and 2 both release, the pulsing circuit over conductors i8 and I9 is therefore opened for a period determined by such adjustments of condenser l2 and resistance Il.

As soon as relay l I releases the discharge path for condenser 9 is established from ground on conductor 3, through condenser and the lower winding of relay l0 to ground at the back contact of relay il and the discharge current from condenser 9 now iiows in such a direction through the lower winding of relay Ill as to hold relay i@ operated.

When relay Il again operates, as soon as the charging current through condenser l2 dies down, relays l and 2 again operate, relay l upon operating reclosing the pulsing circuit. Relay ll also renders the previously traced charging circuit for condenser 9 effective. While current for charging condenser 9 is ilowing through the lower winding of relay lll, relay B releases. 'Ihe capacitance of condenser 9 and the resistance of resistance element i6 may be suitably adjusted to control the period during which relay Ill remains released. With relay I0 released the discharge path for condenser !2 is closed over its back contact and condenser |2 discharges through resistance I3.

When relay l0 again operates, as soon as the charging current through condenser 9 dies down, the charging circuit for condenser l2 is reestablished over its front contact, the contacts of key 2l and through the upper winding of relay l l and relay l I again releases followed by the release of relays l and 2 and the reopening of the pulsing circuit. Thus, the period during which the pulsing circuit is maintained closed between impulses is measured by the period during which relay i0 remains released and until relay Il starts its release period as determined by the adjustment of the capacitance of condenser 9 and resistance of resistance element IB.

tential from .the point between the lower winding Relays l@ and Ei now continue to operate and release, as above described, as long as the key -2I remains operated, relay M upon each operation causing the operation of relays i and 2 to close the pulsing circuit and upon each release causing the release of relays l and 2 to open the pulsing circuit. Thus, the ratio of. the open to closed periods of the impulses transmitted by relay i is controlled by the ratio of the release period of relay i i to the release period of relay i 0. To change this ratio and the speed at which impulses are generated, resistances i4 to lll, inclusive, and condensers Q and i2 may be adjusted in any desired manner. For example, each resistance, such as Ml, may comprise a plurality of units of diierent resistance value and Veach condenser, such as il, may comprise a plurality of units of diierent capacitance which may be selected by keys in accordance with the pulsing speed or ratio of open to closed periods of the impulses to be applied to the work circuit.

What is claimed is:

1. A circuit interrupter comprising two polarized relays each having an operating winding and a control winding, a source of current, circuits for maintaining a constant ow of current from said source through the operating windings of said relays, and a circuit for the control winding of each relay including a condenser controllable by the other of said relays.

2. A circuit interrupter comprising two polarized relays each having an operating winding and a control winding, a source of current, circuits for maintaining a constant ow of current from said source through the operating windings of said relays, a condenser associated with each relay, a charging path for each condenser eX- tending from said source of current through the control winding of the relay with which it is associated, and means controlled by each relay for rendering the condenser charging path through the control winding of the other relay eiective.

3. A circuit interrupter comprising two polarized relays each having an operating winding and a control winding, a source of current, circuits for maintaining a constant flow of current from said source through the operating windings of said relays, a condenser associated with each relay, a charging path for each condenser extending irom said source of current through the control winding of the relay with which it is associatedymeans in each of said charging paths for controlling the charging rate of the condenser connected therein, and means controlled by each relay for rendering the condenser charging path through the control winding of the other relay eiective.

4. A circuit interrupter comprising two polarized relays each having an operating winding and a control winding, a source of current, circuits including adjustable resistances for maintaining a predetermined constant iow of current from said source through ,the operating windings of said relays, a condenser associated with each of said relays, a charging path for each condenser extending from said source of current through the control winding of the relay with which it is associated, an adjustable resistance in each of said charging paths for controlling the charging rate of the condenser connected therein, and means controlled by each relay for rendering the condenser charging path through the control winding of the other relay effective.

5. A circuit interrupter comprising two polar- A ized relays each having an operating winding 75 and a control winding, a source oi' current, circuits including adjustable resistances for maintaining a predetermined constant ilow of current from said source through the operating windings oi said relays, an adjustable condenser associated with each of said relays, a charging path for each condenser extending from said source oi current through the control winding ot the relay with which it is associated, and means controlled by each relay for rendering the condenser charging path through the control winding of the other relay eiiective.

6. A circuit interrupter comprising two polarized relays each having an operating winding and a control Winding, a source of current, circuits for maintaining a constant ow of current from said source through the operating windings oi' said relays, a condenser associated with each relay, a charging path for each condenser extending from said source oi' current through the control winding oi' .the relay with which it is associated, a discharge path for each of said condensers, and means controlled by each relay for establishing the charging and discharging paths for the condenser associated with the other relay.

7. A circuit interrupter comprising two polarized relays each having an operating winding and a control Winding, a source of current, circuits ior maintaining a constant flow of current from said source through the operating windings ot said relays, a condenser associated with each oi said relays, a charging path i'or each condenser extending from said source of current through the control winding of the relay with which it is associated, means controlled by the .operation of each relay ior rendering the condenser charging path through the control winding of the other relay eiiective, a discharge path for each of said condensers, and means controlled by the release oi each relay for rendering the discharging path of the condenser associated with the other relay eil'ective.

8. A circuit interrupter for producing impulses at a predetermined rate, each impulse having a predetermined ratio oi closed to open period, comprising a irst and a second differentially wound polarized relay, each having an operating winding and a control winding, a source oi current, means for establishing operating circuits from. said source through the operating windings of said relays. a ilrst and a second condenser, a charging path for said ilrst condenser extending from said source of current through the control winding of said iirst relay and a discharging path therefor extending through the control winding of said iirst relay and over'the back contact of said second relay, a charging path for said second condenser extending from said source oi current through the control winding of said second relay and over a front contact oi said iirst relay and a discharging path therefor extending over the back contact of said rst relay, and an impulsing circuit controlled over the iront contact ot said second relay, whereby each relay controls the release of the other, the time during which said rst relay is released determining the closed period ot each impulse and the time during which said second relay is released determining the open period oi' each impulse.

ORFEO CESAREO. ROBERT MUELLER.