US3130398A - Electrical code translators - Google Patents

Description

April 21, 1964 A. FREEDMAN 3,130,398

ELECTRICAL CODE TRANSLATORS Filed Dec. 22, 1958 2 Sheets-Sheet 1 E I [m L14 D,

(I) VJ PULSE GEN. R

m VENT ARYE LE/B FRESDMA/V ATTORNEY April 21, 1964 A. 1.v FREEDMAN ELECTRICAL CODE TRANSLATORS 2 Sheets-Sheet 2 Filed Dec. 22, 1958 MWENTOR ARYE LE/B FREED/"IAN QM K M.

ATTORNEY United States Patent 3,130,398 ELECTRICAL CODE TRANSLATORS Arye Leib Freedman, Stevenage, England, assignor to Ericsson Telephones Limited, London, England, a

British company Filed Dec. 22, 1958, Ser. No. 782,021 Claims priority, application Great Britain Jan. 2, 1958 8 Claims. (Cl. 340-347) The present invention relates to electrical code translators such, for example, as are used in telephone exchanges, the translators being of the type comprising a plurality of groups of cores of ferro-magnetic material, each core being provided with a separate output wire magnetically coupled thereto and a plurality of input Wires being provided each of which is magnetically coupled to a plurality of cores selected from different groups respectively of cores.

In such translators as normally operated, a signal applied to an input wire induces output signals in the output wires of each of the cores magnetically coupled to the input wire.

Thus, for example, a translator may comprise four groups of cores, each having ten cores representing the numbers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. Different input wires may thread different sets of cores, each having four cores, one from each group. A selection of four cores, one from each of the four groups, corresponds to the four digits of a four figure number. On the application of an appropriate signal to one of the input wires output signals are provided in four output wires and represent a four figure decimal number. Often the cores are made in the form of rings and the input wires are loosely threaded through the rings to effect the magnetic coupling. Such an arrangement has been found particularly useful since a change of the number corresponding to a given input wire may readily be effected. Thus the wire is pulled out of one set of cores and threaded through a new set of cores to effect the required change.

There is sometimes need for a translator of the type defined wherein provision is made for controlling the times at which output signals are provided from the different groups of cores and it is an object of the present invention to provide such a translator.

According to the present invention an electrical code translator of the type defined comprises a plurality of control wires, magnetically coupled to all the cores of the groups of cores respectively, and a control circuit is connected to the control wires, the control circuit being adapted to provide currents in predetermined control wires or combinations of control wires for selectively allowing the generation of output signals in the output wires of the different groups of cores, or for selectively causing the generation of output signals in output wires of the different groups of cores following the application of an input signal to an input wire.

In this specification the term switchable core means a member of ferro-magnetic material having a hysteresis loop of such shape that on the application and removal of a magnetic field or magnetomotive force of appropriate sense to change the state of magnetisation of the material from one to the other of the two stable states, hereinafter referred to respectively as the datum state and the alternative state, existing in zero external field after saturation of the core in two opposite senses respectively, as the magnitude of the field of the appropriate sense is increased from zero to a first value the flux within the material changes by a relatively small amount, as the magnitude of the field is increased beyond the first value by a value small compared with the first value a relatively large flux change, accompanied by change of sign, occurs and as the magnitude of the field is thereafter decreased to zero only a relatively small flux change occurs.

Materials having hysteresis loops of the shape known in the art as rectangular are suitable materials. A rectangular hysteresis loop may be said to be one for which the remanent magnetic flux in the datum state and the alternative state is or more of the flux at saturation. The above definition is not however limited to cores of such materials.

Thus an input signal may be applied to an input wire and output signals be obtained in sequence from the cores with which the input wire is magnetically coupled. If the groups of cores correspond to the digits of a number the signals representing the digits of the number corresponding to a given input wire may be provided in succession.

The invention can achieve the aforementioned object by making use of the saturation effect of ferro-magnetic cores by applying currents in control wires of magnitude sufficient to produce magnetomotive forces to saturate all the cores in those groups with which the wires are associated. The input signals may be applied as pulses of sense such as to produce magnetomotive forces to magne tise, or tend to magnetise, the cores in the same sense as the currents in the control wires. A pulse in an input wire will only produce an output signal in the output wire of a core not in a group of cores whose control wire is energised by the control circuit. A succession of input pulses may be provided in an input Wire and the different control wires be de-energised in turn, with the other control wires energised, i.e., with N groups of cores and N respective control windings, the control wires are successively de-energised by energising in succession N different combinations of control wires consisting of all said controls wires except one. Thus the digits of a number may be derived in succession. The succession of input pulses may be provided by a rectified alternating current. In an alternative form, unrectified alternating current may be applied in an input wire, the currents in the control wires being of magnitudes great enough to take the cores sufficiently beyond saturation, to prevent an appreciable output signal being induced by the alternating current.

The invention may be carried into effect in a variety of ways when using switchable cores.

A current of half the magnitude necessary to switch a core may be applied to an input wire as the input signal and a further current of half the magnitude necessary to switch the core be applied by the control circuit to the control wire associated with a group of cores from which an output signal is required. A similar effect may be achieved by applying an inhibiting current in an inhibit wire magnetically coupled to all the cores of magnitude sufficient to cancel the effect of the current applied as an input signal to an input wire, which current is made of magnitude sufficient by itself to switch a core. The control circuit applies a current in the control wire associated with a group of cores from which an output signal is required, the current being of a magnitude sufficient to switch the core of the group of cores for which the effect of the inhibiting current is cancelled by the current in an associated input wire.

In other embodiments employing switchable cores an input signal in an input wire is adapted to switch the state of the cores, with which the wire is magnetically coupled, from a datum state to the alternative state. Rectifiers are included in the output wires of the cores which allow output pulses to fiow in the output wires only when the cores are switched back from the alternative state to the datum state. The cores in the alternative state are switched back to the datum state at predetermined instants by currents in the control wires and output signals are thus generated.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic circuit diagram of one embodiment of the invention, and

FIG. 2 is a schematic circuit diagram of a second embodiment of the invention.

Referring to FIG. 1, a translator comprises forty cores CS of saturable (non-rectangular loop) ferro-magnetic material. The cores are arranged in four groups or rows of ten cores each, the cores being numbered 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 in each row. Each core is provided with an output wire U individual thereto.

A number of input wires, of which four (A, B, C, D) are shown, each thread one core from each of the four groups. The wire A threads the core 2 from the first group, the core 4 from the second group, the core 1 from the third group and the core 6 from the fourth group. Thus the wire A corresponds to the number 2, 4, 1, 6. The wires are connected to respective pulse sources S. The wire A is energised repetitively by the source S connected thereto in order to obtain output pulses corresponding to the digits 2, 4, 1, 6. However, the translator is so constructed that the four digits of this number are obtained in succession and not altogether. Thus, the cores CS in the four groups respectively are threaded by four control wires K1, K2, K3 and K4. Each control wire is connected to the output of a corresponding bi-stable device in the series F1 to F4. Each of these devices is such that when in one state a current flows through the corresponding control wire, which current is of such mag nitude as to saturate all the cores threaded by that control wire. When the bi-stable device is in the other state no current flows through the control wire.

Each bi-stable device has two inputs, one of which is connected separately to a pulse generator and the other of which is connected in common to the pulse generator. The pulse generator provides a succession of pulses in the following manner. A set pulse P1 is applied to the bistable device Fl. This sets the bi-stable device F1 to its second state, leaving the bi-stable devices F2 to F4 in their first states. Accordingly, no current flows in the control wire K1, but current flows in the control wires K2 to K4. On the application of a pulse from a source S to the wire A an output is induced in the output wire U of the core 2 in the first group because the cores in this groups are in an unsaturated state. No output pulse is induced in the output wires of the other cores threaded by the wire A since the input pulse provided by the source S only tends to drive these cores further beyond saturation, being of the polarity such as to cause this.

The pulse generator thereafter generates a pulse Q applied in common to all the bistable devices. This pulse is a resetting pulse and resets the bistable device F1 to its first state. A set pulse P2 is then applied to the device F2, setting this to its second state. Accordingly, on the application of a further pulse in the wire A an output signal is induced in the output wire of the core 4 in the second group. A further pulse Q resets the bi-stable device F2. A pulse P3 sets the bi-stable device F3, and the next pulse in the wire A induces an output in the output wire of the core 1 in the third group. After the application of a further resetting pulse Q a pulse P4 sets the bistable device F4 to its second state and a further pulse in the wire A induces an output in the output wire of the core 6 in the fourth group. The pulse generator continues to produce successions of pulses P1, P2, P3 and P4 with intervening pulses Q and so causing each of the four different combinations of all control wires but one, i.e., the four difierent combinations of three control wires, to be energised in succession. Each time the four figure number corresponding to one of the wires A, B, C and so on is required a succession of four properly timed pulses are provided by the source S connected to the selected wire.

In another mode of operation the sources S provide alternating current signals in the wires A, B, C and so on. If the currents in the control Wires are made of sufficient magnitude the alternating current signals will be unable to desaturate the core which they thread and which is also threaded by an energised control wire and, as in the previously described embodiment, an output signal will only be induced in the output winding of a core of the group whose control wire is not energised.

Referring now to FIG. 2, there is shown a similar array of forty cores which are in this instance however, cores of a ferro-magnetic material having a hysteresis loop of the shape known in the art as rectangular. The cores are again provided with individual output wires and a plurality of input wires A, B, C and so on. Each input wire threads one core from each of the four groups of ten cores. Control wires K1, K2, K3 and K4 are again provided. The bi-stable devices are replaced by twogates G1, G2, G3, G4, energised by the pulse generator. The gates are arranged to produce outputs in succession in each cycle of operations. Thus, each gate has one input connected to a common lead L and another input connected to a lead in a series L1 to L4 individual to the gate. The pulse generator provides a pulse P1 of relatively long duration in the lead L and, in succession, pulses P2, P3, P4 and P5 in the leads L1 to L4 respectively. A reset pulse is applied to a lead RR threading all forty cores following the application of each of the pulses P2 to P5. On the coincident application of pulses P1 and P2 to the gate G1 an output pulse is provided in the lead K1. This is of half the amplitude necessary to switch a core from the datum state to the alternative state. Each source S provides a current in its associated input wire A, B, or C and so on, likewise of half the amplitude necessary to switch the cores threaded by that wire from the datum state to the alternative state. Accordingly, on the application of an input current in the wire A which, as will be seen, corresponds to the numher 2, 1, 4, 2, when the gate G1 produces an output pulse P2 an output signal is produced in the output wire of the core 2 in the first group. Thereafter a reset pulse in the lead RR resets this core to the datum state. The subsequent output pulse P3 from the gate G2 causes an output pulse to be induced in the output wire of the core 1 in the second group. The subsequent application of further reset pulses and the pulses P4 and P5 cause output signals to be induced in the output wires of the core 4 in the third group and the core 2 in the fourth group.

This embodiment may again be operated in alternative ways. For example, the pulse generator may energise the lead RR with a continuous current of magnitude and sign such as to switch any core in the alternative state to the datum state. The currents in the Wires A, B, C and so on are then made of sufficient magnitude to, by themselves, switch the cores threaded by the wires from the datum state to the alternative state. The current puEs in the control wires 1(1 to K4 are made of similar amplitude. Again, only a core threaded both by an energised wire in the Wires K1 to K4 and an energised input wire will have its state switched to the alternative state, therer i by inducing an output pulse in its output wire. The core thus switched is immediately returned to the datum state by the continuing current in the lead RR when the current pulse in the energised control wire ceases.

If required, the output wire of each core CS may be provided with a rectifier in order that output pulses may only be passed when the cores change from the datum state to the alternative state or from the alternative state to the datum state.

In a further embodiment the lead lRR is dispensed with. The current supply in the wires A, B, C and so on are made of suflicient amplitude to switch all the cores threaded by the wire from the datum state to the alternative state. Rectifiers are included in each of the output wires coupled to the cores and so poled that no current is passed when the cores are switched from the datum state to the alternative state. The output pulses from the gates G1 to G4 are made of amplitude and sign such that they return any core in the associated group in the alternative state to the datum state. Thus on the application of a current to the wire A the cores corresponding to the numher 2, 1, 4, 2 are set to the alternative state. Pulses are provided in succession by the gates G1, G2, G3, G4, resetting these cores to the. datum state in turn .and producing output pulses in their output wires in turn.

I claim:

1. An electrical code translator comprising a plurality N of groups of cores of saturable, non-rectangular hysteresis loop ferro-magnetic material, a plurality of output wires individual to said cores respectively, a plurality of input wires, each magnetically coupled to a different set of said cores, each said set including one core from each group, a plurality N of control wires including one wire for each group magnetically coupled to all the cores of said group, a control circuit and means connecting said control circuit to said control wires, said control circuit comprising a plurality of energising means individual to sad control wires respectively for applying control signals to said control wires to drive all cores coupled to said wires to saturation in a predetermined sense and means for selectively controlling said energising means to apply control signals in succession to each of the N different combinations of control wires consisting of all said control wires but one, the translator further comprising input means and means coupling said input means to said input wires, said input means applying input pulses to selected input wires in such a sense as to tend to magnetise the sets of cores in said predetermined sense.

2. An electrical code translator according to claim 1 wherein said control circuit comprises a plurality of bistable circuits having output terminals connected to said control wires respectively, each bi-stable circuit applying a control signal to the control wire connected thereto in one state and applying no control signal to the control wire connected thereto in the other state, the control circuit further comprising a pulse generator for providing 7 input pulses to said bi-stable circuits fior selectively and sequentially setting them to their first and second states. 3. An electrical code translator comprising a plurality N of groups of cores of saturable, non-rectangular hysteresis loop ferromagnetic material, a plurality of output wires individual to said cores respectively, a plurality of input wires, each magnetically coupled to a diiferent set of said cores, each said set including one core from each group, a plurality N of control wires including one wire for each group magnetically coupled to all the cores of said group, a control circuit and means connecting said control circuit to said control wires, said control circuit comprising a plurality of energising means individual to said control wires respectively for applying control signals to said control wires to drive all cores coupled to said wires beyond saturation in a predetermined sense and means for selectively controlling said energising means to apply control signals in succession to each of the N different combinations of control wires consisting of all control wires but one, the translator further comprising input means and means coupling said input means to said input wires, said input means applying alternating input signals to selected input wires of magnitude less than that sufiicient to desaturate said cores driven beyond saturation.

4. An electrical code translator comprising a plurality of groups of cores of ferro-magnetic material, an individual output wire for each of said cores magnetically coupled to the respective core, a plurality of input wires, each input wire being magnetically coupled to a set of said cores, each said set of cores including one core from each group, and individual control wire for each group of cores magnetically coupled to apply a magnetomotive force to all the cores of the respective group in response to a control signal in said wire, input means and means connecting said input means to the input wires whereby an input signal may be applied to any selected one of said input wires to apply a magnetomotive force to each of the cores magnetically coupled to said selective one of input wires, each said core being responsive to both an input signal and a control signal in respective input and control wires associated with said core to cause an output signal to be generated in the output wire for the core, and a control circuit means and means connecting said control circuit means to said control wires, said control circuit means being so constructed and operatively connected to apply control signals selectively to said control wires in predetermined timed relationship with respect to the input signals in the selected input wire to cause said output signals from the cores of the set corresponding to the selected input wire and located in the different groups to be generated individually and selectively in timed sequence.

5. An electrical code translator according to claim 4, wherein said cores are switchable cores and wherein said control circuit comprises individual energising means for applying currents in said control wires of the sense and approximately half the magnitude necessary to switch the cores from the datum state to the alternative state and means for selectively controlling said energising means to apply currents in sequence to said control wires, said input means being so constructed and operatively connected for applying currents to selected input wires of the sense and approximately half the magnitude necessary to switch the cores from the datum state to the alternative state.

6. An electrical code translator according to claim 5, further comprising a reset wire coupled magnetically to all said cores and means connecting said reset wire to said control circuit, whereby said reset wire can be energised to return to the datum state each core set to the alternative state.

7. An electrical code translator according to claim 4 comprising an inhibit wire magnetically coupled to all said cores, means connecting said control circuit means to said inhibit wire, said control circuit means comprising individual energising means for applying currents in said control wires of the sense and magnitude necessary to switch the cores from the datum state to the alternative state and means for selectively controlling said energising means whereby currents can be applied to selected control wires, said control circuit means further comprising energising means for applying a current in said inhibit wire of the sense and magnitude necessary to switch the cores from the alternative state to the datum state, said input means being solely constructed and operatively connected for applying currents to selected input wires of the sense and magnitude necessary to switch the cores from the datum state to the alternative state.

8. An electrical code translator according to claim 4, wherein said control circuit means comprises a plurality of gating devices having outputs connected to said control wires respectively, and each having a pair of input terminals, said control circuit means further comprising a pulse generator adapted to apply a relatively long operat ing pulse to one input terminal of each gating device and during the application of said pulse to apply a sequence of relatively short operating pulses to the other inputs of said gating devices respectively, whereby said control wires are energised in succession and output signals from the different cores of a set are generated only at times selected for each of said groups respectively.

2,734,184 Rajchrnan Feb. 7, 1956 8 Abbott July 15, Auerbach July 22, Yetter Aug. 5, Miller Oct. 14, Lawrence Aug. 25, Buchholz et a1 Mar. 29,

FOREIGN PATENTS France Nov. 15, Great Britain Mar. 6,

Claims (1)

1. 4. AN ELECTRICAL CODE TRANSLATOR COMPRISING A PLURALITY OF GROUPS OF CORES OF FERRO-MAGNETIC MATERIAL, AN INDIVIDUAL OUTPUT WIRE FOR EACH OF SAID CORES MAGNETICALLY COUPLED TO THE RESPECTIVE CORE, A PLURALITY OF INPUT WIRES, EACH INPUT WIRE BEING MAGNETICALLY COUPLED TO A SET OF SAID CORES, EACH SAID SET OF CORES INCLUDING ONE CORE FROM EACH GROUP, AND INDIVIDUAL CONTROL WIRE FOR EACH GROUP OF CORES MAGNETICALLY COUPLED TO APPLY A MAGNETOMOTIVE FORCE TO ALL THE CORES OF THE RESPECTIVE GROUP IN RESPONSE TO A CONTROL SIGNAL IN SAID WIRE, INPUT MEANS AND MEANS CONNECTING SAID INPUT MEANS TO THE INPUT WIRES WHEREBY AN INPUT SIGNAL MAY BE APPLIED TO ANY SELECTED ONE OF SAID INPUT WIRES TO APPLY A MAGNETOMOTIVE FORCE TO EACH OF THE CORES MAGNETICALLY COUPLED TO SAID SELECTIVE ONE OF INPUT WIRES, EACH SAID CORE BEING RESPONSIVE TO BOTH AN INPUT SIGNAL AND A CONTROL SIGNAL IN RESPECTIVE INPUT AND CONTROL WIRES ASSOCIATED WITH SAID CORE TO CAUSE AN OUTPUT SIGNAL TO BE GENERATED IN THE OUTPUT WIRE FOR THE CORE, AND A CONTROL CIRCUIT MEANS AND MEANS CONNECTING SAID CONTROL CIRCUIT MEANS TO SAID CONTROL WIRES, SAID CONTROL CIRCUIT MEANS BEING SO CONSTRUCTED AND OPERATIVELY CONNECTED TO APPLY CONTROL SIGNALS SELECTIVELY TO SAID CONTROL WIRES IN PREDETERMINED TIMED RELATIONSHIP WITH RESPECT TO THE INPUT SIGNALS IN THE SELECTED INPUT WIRE TO CAUSE SAID OUTPUT SIGNALS FROM THE CORES OF THE SET CORRESPONDING TO THE SELECTED INPUT WIRE AND LOCATED IN THE DIFFERENT GROUPS TO BE GENERATED INDIVIDUALLY AND SELECTIVELY IN TIMED SEQUENCE.

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