BE536724A - - Google Patents

Description

       

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   The present invention relates to test circuits for automatically testing and adjusting the permanent magnetic polarization of polar relays.
A pole relay is a relay which comprises an energizing winding and at least one contact, comprising a permanent magnet and a movable magnetic armor magnetically attracted to said contact by said magnet and movable under the influence of said winding and said. magnet towards or away from said contact, when said winding is excited by a current of specified magnitude and polarity.

   Such a relay can be enclosed in a glass casing, a typical example being that set forth in U.S. Patent No. 2,609,464, which has a movable frame arranged to make contact with one. or the other of two contacts which are supplied, by capillary action, with mercury coming from a reservoir in the casing, a permanent polarizing magnet for each contact being located outside the casing and the excitation coil surrounding the envelope. This relay is also described in the "Bell System Technical Journal" of November 1953. A similar type of relay, but having only one bias magnet, is described in US Pat. No. 2,577,602.



   The two directions of armature movement are often referred to as "actuation" and "release" and this terminology will be used herein. Current or currents to determine actuation or release of armature. a particular relay are generally referred to as "sensitivities" for actuating and releasing the relay. The main object of the present invention is to achieve automatically, quickly and accurately any value or sensitivity values desired for any relay.



   The general steps of the process employed are described in United States Patent No. 2,590,228 and are as follows
1. Magnetize both magnets completely with a suitable flux.



   2. With the armature starting on one contact, gradually decrease in small steps the magnetization of the magnet on this side until the armature operates just for the other contact with the excitation coil. carrying the current for this direction of movement.



   30 With the armature starting on the other contact, gradually decrease in small steps the magnetization on this side until the armature just drops from this contact with the exciter coil carrying the desired current for this second direction of movement.



   4. Repeat steps 2 and 3 until the relay for just in both directions for the respective current values read.



   Steps 3 and 4 are necessary in a balanced pole relay because the force on the armature is affected by both magnets and an adjustment of the magnetic force of one of them will dominate the effect of the au - be. In the case of the unbalanced polar type of relay having only one magnet, the process would be completed after step 2.



   According to the present invention, there is provided a counter-circuit responsive to a switch having at least two positions in the first of which the control circuit is made to connect a source of pulses of magnetization current to. a coil magnetically coupled to the permanent magnet, the amplitude of these pulses being such that it over-magnetizes the permanent magnet, and in the second of which the control circuit is caused to connect to the coil a source of variable current pulses for demagnetization, of gradually increasing magnitude, the circuit

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 EMI2.1
 of comma---.de connecting # <- ¯ ## ôi seleti: 7 \ ;; :::: ie: r ± t to the actuating coil of the pole relay one soù., - ;;;

   the (jOt ± 'll1j of the establishment of sufficient magnitude to maintain the armatare of the relay on the demagnetized contact during the application of the demagnetization pulses or by connecting during the intervals between the pulses a current source d 'test the magnitude of which is that necessary to drop the armature of this contact when the relay is correctly adjusted and a detector responding to the movement.
 EMI2.2
 ment of the reinforcement s ë = o-taxt d. contact to cause the control circuit to complete the series of demagnetization pulses.



   When the relay to be set has two contacts each of which has an aid
 EMI2.3
 polarizing mant Se .. à 'A detector is provided for each contact, the control circuit being such that operation of the first detector to indicate the release of the armature from the first contact causes the control circuit to apply demagnetization pulses to the demagnetization coil associated with the second contact and that the operation of the second detector indicates? the release of the armature of the second contact causes the control circuit to reapply demagnetization pulses to the demagnetization coil associated with the first contact,

   the demagnetization pulses being thus applied alternately to the two demagnetization coils until the detectors indicate an immediate release of each contact in turn, when the adjustment is completed.



   In the embodiment described later, the switch is manually operable, so that the magnetization step is first performed.
 EMI2.4
 started by putting the COLlliit1.:tateur in position cf "almantatiowl, the switch is then brought to the position of 'deamantat: iori2 and after that the adjustment is carried out automatically under the supervision of the command or control circuit.



   The adjustment steps in the case of a relay with two magnets are as follows:
 EMI2.5
 1. By m.¯., T93 = .t-on dV'l.1.n switch in "magnetization" position, a relay circuit applies a chosen polarity of half a cycle of alternating current as magnetization pulses to electromagnets,
 EMI2.6
 which pulses 3¯-¯ <= Lr- thus the two polarization magnets of the relay.



   By manipulating said switch to a position of
 EMI2.7
 "demagnetization" .. the relay eircait chooses the other ac polarity of half a c3-cie to 1 "apply to one electromagnet at a time, thereby demagnetizing either of the polarization magnets to the
 EMI2.8
 both under the control of a c, ui 'relay control and a selector.



  This control circuit causes the armature of the relay under test to be actuated to one side, for example the "actuation" side, applies a "test" current to the relay, applies a pulse of relatively low demagnetization of specified magnitude of the half cycle chosen as determined by the selector to the associated solenoid, apply a "reset" current to the relay under test to force the armature to operate towards said side, apply a current test to said relay under test and detects whether or not the armature of the relay under test moves to the other side in response to said test current.

   If the armature does not move this way, then the control circuit causes the selector to pre-select a slightly larger magnitude of demagnetization current and apply that slightly larger demagnetization pulse to the associated electromagnet and then repeat the rest. of the above process. If the armature moves, then the control circuit will adjust itself to be able to follow the same process on the other side, that is, the "free" side.

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 tion ", using the other electromagnet, of course, and starting the magnitude of the demagnetization pulses from a specified low value of demagnetization current, as before,
3.

   At the end of the demagnetization cycle on the release side, the control circuit will switch to the actuation side and continue again because the adjustment of the release side will have caused an error in the adjustment of the actuation side. previous.



   4. This process is continued in one direction and the other of the actuating and releasing sides until the detection means in the relay control circuit indicates (for example by rapidly alternating flashing of two associated lamps each side of the relay) that the armature moves in the correct direction for the correct sensitivity or test current applied respectively to the coil of the relay under test.



   Two embodiments of the invention are described in the subsequent detailed description, taken together with the accompanying drawings in which - Figure 1 shows in block diagram form a functional arrangement of a typical adjustment device arranged for demagnetization; FIG. 2 illustrates how to arrange FIGS. 6 and 7 to show a complete circuit according to one of the embodiments of the invention; the figure illustrates how to arrange FIGS. 8 and 9 to show a complete circuit according to another embodiment of the invention; FIG. 4 shows a curve or graphical report of test data applicable to the circuit of FIGS. 6 and 7, which representation is considered in the detailed description as an aid for understanding the operation of the circuit of FIGS. 6 and 7;

   - Figure 5 shows data similar to those of Figure 4 but associated with the circuit of Figures 8 and 9; FIG. 1 shows a functional block diagram of an arrangement of a device for automatic adjustment of a relay, according to the present invention. The relay subject to adjustment, relay 100, is shown with its housing open to show the armature 108 with an exciter coil 111 surrounding it and two contact elements 109 and 110 each including a permanent magnet. The relay 100 is placed inside a suitable frame which carries two arrangements of magnetization and electromagnetic de-magnetization chops, such as 101 and 102.

   A control circuit 103 is arranged to select in certain circumstances specified polarities of alternating current half-cycle pulses and to apply these through the actuation or release path through the respective initial and release steps. end of the energy magnitude selectors 104, 105, 106 and 107 to one or the other of the electromagnets 101 and 102.

   The control circuit 103 also, at times, exerts an actuate-release control and a test reset control by actuating the test circuit in cooperation with certain current control circuits of the test circuit. relays under test which apply test current values and. re-establishment for the directions of actuation and release of movement of armature 108.



   A table of abbreviated notations used in the drawings is given at the end of the description.

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   In short, the operation of the circuit is as follows. Assuming that the direction of release of movement of the armature 108 goes from contact 109 to contact 110 and that the direction of actuation is the opposite direction and assuming that the armature is initially in contact with the contact 110, the relay current setting circuits are first established so that when an actuating or releasing current for the test, or test reset, is to be transmitted by coil 111 of relay 100, these values are those specified for the relay being set. Selector switches 105 and 107, including fine adjustment, will be set to their minimum voltage indications.

   The variable autotransformers 104 and 106, including the coarse adjustment, will be adjusted to some predetermined value, of relatively large value. In response to the operation of a manual switch, the power control circuit 103 will apply to the two electromagnets 101 and 102 a few half cycles of specified polarity (e.g. positive half cycles) of alternating current energy, in so that each of the permanent magnets 109 and 110 comprising the relay contacts are over-magnetized.

   After that, the coarse controls 104 and 106 are manually set to a chosen position of minimum voltage and the control circuit 103 will choose the autotransformer 106, the selector switch 107 and the electromagnet 101, and will only pulse. Half cycles of reverse polarity, relatively low level, of demagnetization current will be applied to the electromagnet 101 for the purpose of partially demagnetizing the magnet contact 110 of the relay 100.

   While this particular half cycle of demagnetization current is applied to the electromagnet 101, the release recovery current value will be applied to the coil 111 of the relay 100 to ensure that the armature 108 remains on. contact with the actuated magnet contact 110. As soon as this demagnetization current de-: ni-cycle pulse is completed, the control circuit 103 will cause the release current test value to be applied. to winding III to determine whether or not the armature 108 will pass from contact 110 to contact 109.

   Normally, in response to the first demagnetization pulse, armature 108 will not function as desired, after which control circuit 103 will release the power selector to self-adjust to a small magnitude. greater demagnetization voltage and will again apply this increased demagnetization voltage to electromagnet 101 at the same time as the stated amount of release recovery current will be applied to coil 111. As soon as this second demagnetization pulse is At this point, the test release current is reapplied to winding 111.

   This process is repeated until the moment when the actuation contact magnet 110 is sufficiently demagnetized to allow the armature 108 to move towards the release contact magnet 109.



   The control circuit 103 detects the displacement of the armature from the actuator contact 110 to the release contact 109 in response to the pre-selected value of the release test current. Then the control circuit 103 switches its power control from the release side to the actuation side, thereby enabling the autotransformer 104 and the selector 105 to apply demagnetization pulses only to the e- electromagnet 102.

   The above process, by which successively increasing increments of half-cycle demagnetization pulses are applied to the electromagnet 101, is repeated with respect to the electromagnet 102 except that the reset and test current adjustment circuits that are used are the actuation values instead of the release values. Optionally, the armature 108 will move in response to the actuation test current of the release contact magnet 109 to the actuation contact magnet 110 as an indication that

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 mant 109 has been demagnetized to the extent necessary.



   The demagnetization process continues on either side until the control circuit 103 detects that the setting of the two magnets
109 and 110 is relatively close to the desired final settings, and then can, according to one embodiment of the invention, engage the fine-tuning selector switches 105 and 107 instead of the autotransformers 104 and 1060. the control of the fine adjustments, the deactivation continues with the successive adjustment of the magnets 109 and 110 until the armature 108 is activated and it releases in response to the aotation and release currents of the desired way.

   This represents a state, as detected by control circuit 103, indicating that relay 100 has been properly set and the test is complete.



   Figure 4 illustrates generally what happens during the various adjustment sequences where a shift is provided between coarse and fine power controls which exists in the embodiment of Figures 6 and 7 'At sequence 0, the sensitivity release and the triggering sensitivity of the relay under test are -20 ampere-turns and +43 ampere-turns respectively. This represents the super-magnetization state of the two magnets before the demagnetization process.



   The first set of settings, whereby magnet 110 (the energizing magnet contact) is demagnetized until the armature moves to the release contact 109 in response to the pre-selected value of current. release test, puts the relay under test in a state where the sensitivity. respective release and actuation are +10 and +82 ampere-turns. Thereafter, an adjustment sequence is carried out on the magnet of the energizing contact 109, & la. end of which the respective release and actuation sensitivities are +3 and +56.



   After that, the circuit alternately causes an adjustment sequence towards the release and actuation sides. at the ninth adjustment sequence, the relay release sensitivity is +30 and the aotation sensitivity is +47, these values being assumed to be the final values of the relay sensitivities,
Somewhere, approximately in the vicinity of the fourth or fifth or sirth sequence, the circuit will automatically switch from re-, lA ,.

   coarse to fine tuning Fig. 5 is an illustration of what happens during the various tuning sequences of a test run according to another embodiment of the invention, as set out in figures 8 and 9, in which there is no change from coarse to fine tuning, but in which the whole process is controlled by fine tuning.



     Based on this box each of the decametization and actuation adjustment sequences * will bring the particular contact magnet under treatment to its respective test values. Each liver, however, due to the interaction of the two magnets, successive adjustments on the opposite sides will influence the previous adjustment on the other side. Eventually, however, as was the case in Figure 4, the ninth setting will be close to the desired final test values.



   In Figures 4 and 5, it will be appreciated that each of the lines on the curves marked with a black arrow represents an entire adjustment sequence of the particular release or actuation side, as indicated, and that each of these Tuning sequences may include any number of separate consecutive demagnetization pulses and current and recovery tests for that side.



   In the embodiment of Figures 6 and 7, the relay 1 to

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 Figure 7 is the relay under test and is shown as comprising an armature 718, an energizing winding 719, an actuating contact 716 with an associated permanent magnet 717 and a release contact 714 with an associated permanent magnet 715.

   Located near the respective magnets 717 and 715 are the magnetization and demagnetization coils 713 and 7120 The armature 718 will be in contact with one of the contacts, for example, with the release contact 7140
With the two-pole double-push switch 723 in either of its two positions and with switch 724 open, a circuit is closed from the voltage divider comprising resistors 721 and 722 to the battery terminals. , going to switch 723 via mili- ammeter 725, exiting switch 723, passing through the secondary of transformer 726, winding 719 of relay I, contact 1 of relay H, contact 1 of relay C to the potentiometer 702 comprising part of the voltage divider including potentiometer 702 and resistor 703 at the battery terminals.

   By observing milliammeter 725 and adjusting potentiometer 702, the desired predetermined value of actuation test current can be established. By activating switch 720 to the reset position, relay H. will be activated, extending winding 719 of relay I through contact 2 of relay H and contact 1 of relay D to potentiometer 705 which includes part of the relay. voltage divider including resistor 704 in series with potentiometer 105 across a battery. By moving the bipolar double push switch 723 to the appropriate position and adjusting the potentiometer 705, the pre-selected value of the actuation recovery current can be set.



   With relay H actuated, actuation switch 737 in the released position actuates relays N and M of figure 6 and relays B, C and D of figure 7. The operation of relays N, K and B is uninteresting at the moment. Relays C and D are actuated in a circuit extending from earth to the negative pole of the battery, passing through switch 737, conductor 638, the windings of relays C and D in parallel. With switch 723 in the correct position, a circuit is now closed by milliammeter 725 and the second of transformer 726, winding 719 of relay J, contact 2 of relay H and contact 2 of relay D to the switch. potentiometer 709 comprising part of the voltage divider, including resistor 707 and potentiometer 709 at the battery terminals.

   By observing milliammeter 725 and adjusting potentiometer 709, the pre-selected value of the release state restoration current can be properly set.



   By keeping switch 737 in its released position and returning switch 720 to its test position, relay 4 will be released, after which the circuit described previously, which passes through coil 719 of relay I is switched. on contact 1 of relay H and contact 2 of relay C at potentiometer 708, by means of which setting the test value of the current can be established, at the end of which the switch 720 can be momentarily placed in its position reset to apply the current release reset value to winding 719 to ensure that the armature 718 of that magnet contacts release contact 714.

   Then, switches 737 and 720 can be returned to their respective actuation and test positions leaving armature 718 in the position shown in Figure 7.



   To put the circuit into an automatic state, switch 724 is closed to bypass meter 725 and switches 737 and 720 are placed in their respective "on" positions. In this state, all the relays of the circuit in figures

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6 and 7 are in the states shown.



   In Fig. 6, after the switch 614 is closed, the alternating current power source 633 is applied by the two bus bars marked 01 and # 2 which go to the terminals of the same indication of; autotransformers 604 and 609, to the primaries of transformers 612 and 613, and to potentiometers 610 and 611. Hand tuning knobs, such as 605, can be moved to tune autotransformers and potentiometers 604, 609, 610 and 611 to their minimum voltage positions corresponding to phase 01. This manual adjustment is possible because magnetic clutches, such as electromagnet 603 and friction clutch 602 associated with autotransformer 604, are not energized.



   With these various initial settings of the coarse and fine energy selection controls for the actuation and release sides, it will be noted that the cursor of the autotransformer 609 carries the zero voltage with respect to phase 01 and apply it to terminal # 1 of the potentiometer
611, whereupon the slider of the potentiometer 611 takes the zero voltage with respect to # 1 and applies it through the conductor 636 in figure 7 to the right of the electromagnet 713, the left side of the magnet of winding 713 extending to contact 2 of relay B.

   Similarly, in Figure 6, the slider of autotransformer 604 takes the zero voltage with respect to phase # 1 and applies it to terminal # 1 of potentiometer 610, so that the slider of potentiometer 610 carries zero voltage. with respect to # 1 and applies it through conductor 35 in Figure 7 to the left of the coil of the electromagnet 712, the right side of the coil of the latter extending to contact 1 of the relay B.



    In Figure 6, phase 01 of the alternating current power distribution bar extends through resistor 634 and through the conductor
637 in figure 7, up to the contact of relay A. It will therefore be visible that when relay A is actuated, phase 01 of the alternating current energy will be applied by conductor 637 through the contact of re - leave A to the armature of relay B, after which, depending on whether relay B is released or activated, phase 01 will extend through contact 1 or 2 of this and through the respective electromagnet 712 or 713 to the driver 635 or 636 extending in Figure 6 to, fine and coarse energy selector controls associated with respective electromagnets 712 and 713,

   namely the actuation and release commands. It will also be noted that any increase in power which may have been chosen by the energy control circuit of FIG. 6 with respect to phase 0. will then be applied by conductor 635 or 736 to the electromagnet. associated magnetization-deactivating 712 or 713. In FIG. 6, the zero points for the energy increases with respect to phase 01 are indicated by arrows associated with the cursors of the autotransformers and potentiometers.



   To begin the test, the cursor of the autotransformer 604 is set to a position which represents an AC voltage sensitive magnitude on the cursor relative to the wire terminal. A similar adjustment is made at the autotransformer 609. this quantity of energy in alternating current goes through the conductors 635 and 636 to the electromagnets.
712 and 713, returning to contacts 1 and 2 of relay B, either of which will be extended to the armature of relay A.



   The magnet-demagnetize switch 615 will now be actuated to its upper or magnetization position, causing the following circumstances to occur:
1. At its outer right switching blade, switch 615 interconnects conductors 640 and 641 which, as will be seen at

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 figure 7, amounts to short-circuiting contacts 1 and 2 of relay Bo This puts the electromagnets 712 and 713 in parallel between their respective power source conductors 635 and 636 and the contact 1 of relay B which, when the relay A is actuated, will be extended by conductor 637 in figure 6 and by resistor 634 to phase # 1 of the alternating current power source.



   2e With switch 615 in its upper or de-magnetizing position, phase # 2 of the alternating current power source 633 is extended on the inner left blade of switch 615 towards the vibrating arm of relay L, to the winding of relay K, to the primary windings of transformers 623 and 624, to the winding of relay N, and through conductor 638 in figure 7 to the windings of relays '13, C and D.



  The only important connections in this respect are that phase # 2 is connected to transformers 623 and 624 and to the vibrating armature of relay L.



   3. A circuit is closed from phase # 2 on the armature of relay L, by contact 2 of relay L, conductor 642 in figure 7, by potentiometer 727 to phase # 2 on conductor 639 returning to Figure 6. There is therefore no AC power applied to transformer 726 when switch 615 is in its upper or magnetization position.



   4. Phase # 2 goes from the armature of relay L through contact 1 of the latter to the right terminals of the actuation and release control motors 600 and 6060. The left terminals of these control motors are extend to the respective contacts 1 and 2 of relay K and by the armature of relay K, depending on whether relay K is released or activated, returning to the phase # 1 bar. The right terminals of the energy control motors at the end of adjustment 607 and 608 extend through the contact of relay M to contact 3 of relay L. It is thus visible with relay L in the In the position shown in Fig. 6, the coarse tuning motors 600 and 606 are made to operate and the fine tuning motors 607 and 608 are switched off.

   The opposite is true, as will be underlined in the following description, when relay L is actuated so that its armature makes contact with its 3rd contact.
Autotransformer 620 chooses a suitable magnitude of AC voltage on the secondary of transformer 624, a part of this appearing across resistor 622 in the voltage divider comprising resistor 621 and 622 in. being applied to the series circuit comprising the winding of relay E and capacitor 632. This causes a specified level of alternating current to flow in this circuit through the winding of relay E, which level is too low to make. operate relay E on alternating current alone.

   However, it will be observed that the negative pole of the battery (the positive pole being earthed) is applied by the armature of relay E and its contact 2, by potentiometer 630 and by resistor 631, by l winding of relay E and ground through resistor 622. Also, it will be observed that capacitor 632 shunts the lower side of the winding of relay E to ground. In this position of relay E, capacitor 632 will acquire a charge at a rate determined by the adjustment of potentiometer 630. The variables of the air-cured are preferably chosen so that the maximum value of direct current which can flow through l The winding of relay E is less than the actuation value of the current for relay E.



   As the direct current flowing through the relay winding

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E increases exponentially (then as the charge of capacitor 632 increases), the arrangement is such that for a certain suitable value, it will be sufficient, with the alternating current injected into the relay circuit, to actuate relay E When this happens, the armature of the relay
E moves from its contact 2 to its contact 1. This removes the DC load circuit for capacitor 632 and allows capacitor 632 to discharge in the circuit comprising resistor 622 and the coil of relay E. The voltage across capacitor 632 will therefore decrease at an exponential rate determined by the resistance in this discharge circuit.

   Since this resistance is fixed for any setting of autotransformer 620, the time constant of the discharge circuit for capacitor 632 is substantially constant. When the discharge current in this circuit, including the relay winding
E, has decreased to a sufficient extent, relay E will drop again, after which the armature of relay E again makes contact with its contact 2 to cause the cycle described above to repeat.



   Potentiometer 630, as discussed above, changes the time constant in the charging circuit of capacitor 632, thereby varying the magnitude of time from a specific starting point for which relay E will operate. Potentiometer 630, therefore, may be referred to as "close proportion control";

   that is, it will control how long the armature of relay E is in contact with its contact 1 in comparison to the total time compressing the previous one plus the time during which the armature of relay E is in contact with contact 20
At the moment when the armature of relay E makes contact with its contact 1, a circuit is closed, starting from the negative pole of the battery, passing through the armature of relay E, contact 1 of relay E, resistor 629, potentiometer 628, the winding of relay F, the secondary winding of transformer 623, contact 2 of relay J, to earth.

   The phasing of transformers 623 and 624 is arranged such that the upper side of the winding of relay F carries the same phase of alternating current as the upper winding of relay E, as shown in figure 6 by the sign corresponding to the same phase. Potentiometer 628 simultaneously adjusts the levels of the alternating and direct currents which are allowed to flow through the winding of relay F and thus sets the time at which the composite current through the winding of relay F reaches for the first time the actuation value, at which moment the armature of relay F will change from its contact 2 to its contact 1.



   When relay F passes to its contact 1, a circuit is closed from earth, passing through the armature and contact 1 from relay F to conductor 644 extending in figure 7, through the winding from relay A, and up to the negative battery blade passing through a parallel circuit of capacitor 701 and potentiometer 700, and conductor 644 extends through the positive passage of switch * 720 to actuate relay E in a goal to be described later. Capacitor 701 in the circuit of relay A instantaneously shorts across potentiometer 700 and allows relay A to operate very quickly after conductor 644 has grounded. Sooner or later, next When setting potentiometer 700, capacitor 701 will have sufficient charge to cause relay A to drop out.



   The settings of potentiometer 628 in the circuit of relay F and of potentiometer 700 in the circuit of relay A can be considered, respectively as a start of pulse and end of pulse potentiometer, so that the specific instant determined with respect to the waveform of the alternating current for which relay A will operate is

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 determined by potentiometer 628 and that the specific instant of release of relay A by comparison with the same alternating current waveform is determined by the setting of potentiometer 7000
The net effect of this relaxation oscillator type relay circuit is that relay E will be actuated and released at a frequency which is preferably a sub-harmonic of the alternating current wave frequency,

   (but in general can be any whole multiple of the cycle time or period of 1 wave of alternating current), such as for example 4 or 5 times per second compared to a source of alternating current with 60 periods and such as the relay A can be actuated and released at specific times with respect to the alternating current waveform.
As previously described, phase # 1 of the alternating current energy in Figure 6 is applied by resistor 634 and by conductor 637 in contact with relay A.

   If relay A is activated, phase # 1 is extended from conductor 537 through the contact of relay A and through contact 1 or Z of relay B or both to solenoid 712 or 713 or both , and then returns through lead 635 or 636 or both, to the slider or sliders of the fine-tune energy control potentiometers, 610 or 611 or both, to apply a pulse of alternating current energy to either or both of these electromagnets during the time when relay A is actuated An oscilloscope can be mounted across resistor 634 to observe the half cycle of alternating current energy which is transmitted by the contact of relay A.

   With such a continuous indication, the various settings, such as those of 1 autotransformer 620 and potentiometers 630, 628 and 700, can be set such that the fraction of ac energy delivered by the closed contact of the relay A can be exactly a positive or negative half cycle
These energy half-cycle pulses of chosen polarity are considered as magnetization pulses, so that each of the permanent magnets 715 and 717 associated with the release and actuation contacts 714 and 716 of relay I (the relay to be tested) are over-magnetized.



   After the operator has satisfied himself that sufficient time has been allowed for these magnetization pulses to become effective (in fact a single pulse is sufficient) switch 615 is transferred from its upper position to its lower position or demagnetization, and transformers 604 and 609 are manually set low to their # 1 terminals. As a result of these operations
1. The phase of the alternating current energy applied to the primaries of transformers 623 and 624 is inverted so that the energy pulses which are transmitted by the contact of relay A are of reverse polarity with respect to a those described previously o These new energy pulses will be called demagnetization,
2.

   Phase # 1 will be applied to the outer left blade of switch 615 to the armature of relay L and from there through contact 2 of this one and conductor 642 at the top of potentiometer 727, so that current AC will be betrayed by transformer 726 to be injected in series with the DC test and restoration values, pre-selected by potentiometers 702, 705, 708 and 7900
3. The right outer blade of switch 615 removes the short between conductors 640 and 641, which removes the short to the wires.

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 terminals 1 and 2 of relay B in figure 7.

   This allows relay B to choose by releasing or actuating which of the two electromagnets 712 and 713 will be allowed to receive the demagnetization pulses transmitted by the contact of relay A.



   4. A circuit is closed, consisting of earth, the inner right blade of switch 615, resistor 617, and the battery, passing through the windings of all of the magnetic clutch magnets, such as magnet 603, causing all clutches, such as the clutch
602, engage, so that the respective drive motors, if supplied with power, will, by their respective reduction gears, such as 601, cause the associated sliders of the autotransformers
604 and 609 and potentiometers 610 and 611 move slowly from their terminals 01 to their terminals # 2. 5. A circuit is closed, which includes the earth, the right middle blade of switch 615, resistor 618 and the negative pole of the battery, by the winding of relay L.

   Capacitor 646 across the coil of relay L will receive a load which is insufficient to cause relay L to operate, but sufficient for relay L to operate when actuated by other means.



   At the same time as the operation of relay F from its contact N 1 to its contact N 2 which, as indicated previously, actuates relay A by applying earth to conductor 644, relay H is also actuated. by an extension of conductor 644 by the on position of switch 720. Relay H, while operating, applies the recovery current value coming from potentiometer 705, by contact 1 of relay D and contact 2 of relay H by winding 719 to the relay under test I, by the secondary winding of transformer 726 and by switches 723 and 724 to the connection of resistors 721 and 722.

   As explained previously, this value of the re-energizing current will ensure that the armature 718 of relay I remains in contact with its contact 714 during the time when relay A is actuated to apply a demagnetization pulse to the electromagnet. 712.



   Relay A will drop out, terminating the application of a demagnetization pulse to the electromagnet 712, at a time determined by the setting of potentiometer 700, as previously described. As soon as relay F drops back to contact 2, relay H drops out.



   Releasing of relay H, therefore, occurs during the time when relay A is also released, which represents the time interval between applications of demagnetization pulses to electromagnet 712. Relay H, on releasing , closes a circuit starting from potentiometer 702 and passing through contact 1 of relay C, contact 1 of relay H, through winding 719 of the relay under test I, through the secondary of transformer 726, etc. to apply the prescribed value of the actuation test current to the winding 719 of relay I. As discussed previously, this actuation test current value is the value which will cause the armature 718 of relay I from contact 714 to contact 716 of relay I when the permanent magnet 715 has been properly demagnetized.

   However, a suitable amount of alternating current is injected by transformer 726 so that armature 718 will complete the transfer earlier in the demagnetization cycle of permanent magnet 715 than would otherwise be the case.



   If the armature 718 of relay I does not perform the requested transfer, there is no change in the operation of the circuit and relay A is actuated again at the same time as relay H to apply another pulse. demagnetization with the electromagnet 712, this

 <Desc / Clms Page number 12>

 times by a slightly increased magnitude due to the fact that during the intermediate time the autotransformer 604 has moved further from its terminal # 1. When operating relay H, as before, the pre-selected value of the operating recovery current is applied to winding 719 of relay I to ensure that armature 718 remains in contact with release contact 714. of relay Io After that, as soon as relay A has dropped and relay H has dropped,

   as proof of the fact that the demagnetization pulse has passed, the relay H having fallen again again applies the actuation test current value to the winding 719 of the relay Io
This process continues until 1 armature 718 of relay I passes to its actuating contact 716 during the time interval between the applications of the demagnetization pulses to 1 electromagnet 7120 When this transfer takes place, a circuit is closed starting from the negative pole of the battery, by armature 718 of relay I, contact 716, resistor 729,

   to the right side of the lower winding of relay G and to conductor 643 extending towards the earth passing through contact 2 of relay Fo Note that capacitor 736 bypasses the lower winding of relay G thus causing a slight delay in the operation of relay G, after which delay the armature of relay G will be actuated to make contact with its contacts 2 and 30
After the armature of relay G has moved to the right, the earth is extended by the armature of this relay and by contact 3 of relay G, by capacitor 733 and by conductor 645 on the upper side of the relay. winding of relay Jo This earth impulse increases the load existing on capacitor 647, so that the relay will cause its armature to switch from contact 2 to contact 1,

   where the armature of relay J will remain for a short interval of time depending on the time it takes for capacitor 733 to charge. After this short interval of time, relay J will fall back on its contact 2 During the time when the relay is actuated on its contact 1, the relay @ will be actuated in an obvious circuit for a purpose which will be described later. The relay J, operating for a short time, immobilizes the relay F circuit, thus allowing the armature of relay F to remain in contact with its contact 2, and thus preventing the immediate reactivation of relays A and H when relay E continues to oscillate
Relay G, by actuating its armature to the right, also closes a circuit going from the earth, by its contact 2, by the on position of switches 737,

   to conductor 638 which, obviously, causes the operation of relays B, C and Do The earthing of conductor 638 in FIG. 6 causes the operation of relays N and K.



  Relay N, while operating, applies an earth pulse through its L contact through capacitor 626 and through resistor 619 at the left side of the L relay winding. Capacitor 626 goes very fast, however. , acquire a load which then removes 1 additional pulse from the coil of relay L, and relay L is arranged so that this single pulse will not make it operate. Relay K, when operating, transfers phase # 1 of AC energy from its contact 1 to its contact 2, thereby stopping the operation of the motor 600 and starting the operation of the motor 606.

   In addition, during the time that the armature of relay G is in contact with its contacts 2 and 3, capacitor 732 previously charged associated with contact 1 of relay G will discharge through resistor 7350
After relay J in figure 6 drops out, after its momentary operation as described, the circuit for relay F is again

 <Desc / Clms Page number 13>

 closed and the relaxation oscillation relay circuit comprising the relays E and F comes into play to produce the operation of the relay A of FIG. 7 to reapply a demagnetization pulse through its contact.

   However, with relay B actuated, this demagnetization pulse, the magnitude of which is determined by the now continuously increasing value of the alternating current voltage selected by the autotransformer 609 under the control of the motor 606, will be transmitted by the contact 2 from relay B to solenoid 713. During the time interval when relay A is actuated, relay H will be actuated again, as previously described, and a circuit will be closed by release reset potentiometer 709 ' by oontacts 2 of relays D and H to apply to the winding 719 of relay I the predetermined value of release restoration current so that armature 718 of relay I is forced to remain in contact with contact d 'actuation 716 of relay I.



   During the interval between the pulses when relays A and H are released, as described above, a circuit is closed by the release test reset potentiometer 708 through contact 2 of relay C and contact 1 of relay C. relay H, so that the predetermined value of release test current is applied to winding 719 of relay I to determine whether or not armature 718 will return to release contact 714. As explained previously, this release test current is increased again by the AC portion transmitted by transformer 726.



   If armature 718 does not return to contact 714, the demagnetization process described above is repeated so that another demagnetization pulse is transmitted to electromagnet 713.



   When armature 718 performs the desired transfer or passage, a circuit is closed, comprising the battery by its negative pole, armature 718 of relay I, contact 714 of relay I and resistor 728 up to right side of the upper winding of relay G. Relay G will operate in the same way as described above, after a short delay caused by the short-circuit effect of capacitor 730, to move its armature from right to left, thus releasing relays B, C, D, N and K.



   This returns the entire control circuit to its state where the demagnetization pulses will again be applied to the electromagnet 712 associated with the release contact 714 of relay I.



   This back and forth or forward and backward process will continue under the control of the coarse control autotransformers 604 and 609, until relay G operates and drops out of its contact A at a sufficient speed such that relay N in figure 6 is actuated and released at a very rapid rate, so that a succession of earth pulses are applied by contact 1 and relay N to the coil of relay L. J is also actuated and kept actuated by the rapid beats of relay G by contacts 3 and 2. This immobilizes relay F and activates relay 14, thus stopping the de-magnetization process.

   Such a rapid beating in the winding of relay L will cause capacitor 646 shunted on it to acquire a sufficiently increased charge to cause relay L to activate its armature by putting it in contact with its contact 3, the armature then being maintained. in this position because of the continuous charge of capacitor 643.

   Relay L, by operating in this way, causes the energy circuit for motors 600 and 606 to be open and causes the energy circuit for motors 607 and
608 is closed by contact 3 of relay L and the relay contact. (at. the instant when relay M drops when releasing relay J in contact with contact 2 of relay J as described previously),

 <Desc / Clms Page number 14>

 of relay L, in addition to activating the control or fine-tuning command in the upper right-hand part of figure 6 instead of the coarse command as carried out previously, also removes from contact 2 of relay L the circuit described beforehand so that the transformer 726 of figure 7 receives energy in alternating current o This stops the oscillation of the relay I,

     after which relays M and J drop and relays N and G alternately cease to function and drop again. This means that during the remaining part of the relay setting there will be no more alternating current superimposed on the test currents injected into winding 719 of relay I and the circuit can continue its automatic operation while that the sliders of the end of energy control potentiometers 610 and 611 move slowly from their terminals 01, towards their terminals # 2 to apply a very small but nevertheless increasing magnitude of alternating current demagnetization pulses to the two electromagnets 712 and 7130 Optionally,

     a point will be reached where the armature 718 of relay I will even faster and faster move forward and backward between contacts 716 and 714, and in turn will cause the relay to switch rapidly into one and the other direction between its contacts 1 and 3, after which sufficiently fast pulses will be applied to conductor 645 to cause relay J to remain actuated in the position where contact I of relay J is continuously earthed. This causes a continual operation of the relay M so as to open the actuation circuit for the motors 607 and 608 on contact with it to stop any new demagnetization process.



   This state of affairs is visually indicated by the two lamps 710 and 711 in figure 7 which, in this state, will flash very quickly At this point the operator will move the switch 615 to the disengaged position and remove the mounting of electromagnet in preparation for repeating the previous test on a new relay.



   Before starting a new test, the operator will readjust the end adjustment potentiometers 610 and 611 to their minimum or to positions # 1 and may or may not return the autotransformers 604 and 609 to their starting positions. In figure 6 the switch "end" 627 can be closed by hand, if desired, assuming a coarse setting of autotransformers 604 and 609 has been predetermined. This will cause relay L to act immediately, as it will be. obvious, so that only motors 607 and 608 controlling the fine tuning energy control will be effective.



   The embodiment of Figures 8 and 9 differs from the embodiment of Figures 6 and 7 by the following main features:
1. The means by which successively increasing variations in demagnetization current are provided by the ac power source include a pair of stepping switches shown at the top left of Figure 8. These The switches return to normal on their own and therefore do not need to be manually readjusted to their starting positions before each relay setting cycle.



   2. There is no rough control of the variations in magnitude of the demagnetization pulses. The total variation of the step selectors provides equal variations of energy during the entire test and there is no alternating current superimposed on the relay test currents.

 <Desc / Clms Page number 15>

 



   3. A number of additional control or command relays are provided, as will result from the following description.



   Referring to Figure 9, the relay under test is shown at the right-hand side in the manner previously discussed with respect to Figure 7. With the main power switch 802 in Figure 8 not actuated and with magnetization switch 900 and demagnetization switch 901, on switch 902 and on switch 904 also not actuated, the various actuation and release currents of the values of reset and test can be set on potentiometers 906, 909, 912 and 913 in much the same manner as described with respect to the circuit of Figures 6 and 7.



   With release switch 903 and reset switch both unactuated, relays 3, 4 and 5 will be in the position shown in figure 9. After that, by manipulating the switch
915 in one direction or the other according to the polarity of the current to be read by the measuring instrument 917 (assuming that the switch 916 is open), the adjustment of the potentiometer 906 allows that the predetermined value of the current d The actuation test flows in a circuit extending from the cursor of potentiometer 906, passing through contact 1 of relay 3, contact 1 of relay 5, winding 921 of the relay under test, contact 1 or 2 of switch 915, measuring instrument 917, contact 3 or 4 of switch 915, up to the cursor of potentiometer 914 and thence to the battery.

   Meter 917 will indicate when the setting of potentiometer 906 has been set to the prescribed run test current value. Now, with switch 903 closed, actuating relays 3 and 4 in an obvious circuit to ground, which passes through contact on switch 903, potentiometer 912 will operate through contact 2 of relay 3 and contact 1 of relay. 5 to establish the prescribed value of the test release current. With switch 903 actuated, switch 905 is also actuated, thus actuating relay 5 in an obvious circuit, potentiometer 913 can be set so that it acts by contact 2 of relay 4 and contact 2 of relay 5 to adjust the prescribed value of the release recovery current.

   Now with switch 905 activated and switch 903 released, thus maintaining relay 5 activated and releasing relays 3 and 4, the potentiometer
909 acts by means of contact 1 of relay 4 and contact 2 of relay 5 to establish the prescribed value of the actuation recovery current. Switches 903 and 905 can then be released and switch 916 can now be closed to bypass meter 917.



   When the main power switch 802 in Fig. 8 closes, AC power is applied from its source 800, through fuse 801 and switch 802, to both power lines. AC current designated as phase 01 and phase # 2. This applies energy to the primary windings of transformers 816,
810, 804 and 803 and also applies AC power to the variable autotransformers 811 and 805.



   To carry out the initial over-magnetization of the permanent magnets
925 and 924, associated with the respective release and actuation contacts 922 and 923 of the relay under test, the magnetization switch
900 will be closed, causing the following operations
1. The relays 15 and 16 of figure 8 will be actuated in a circuit starting from the ground and passing through the contact 4 of the switch.
900 and conductor 845 to the winding of relays 15 and 16.

 <Desc / Clms Page number 16>

 



   2. A circuit is closed, starting from the earth and passing through the contact 5 of the switch 900, the conductor 838 in figure 8 and through the contact of the relay 11 to earth at the bottom terminal of the nut. - secondary element of transformer 8030
3. Earths are extended by contacts 1 and 3 of switch 900 and by respective conductors 848 and 856 extending in FIG. 8 to respective sliders 820 and 824 of the two pitch selectors.



   4. A circuit is closed to actuate relay 14 in figure 8, extending from phase # 2 to phase # 1 of the power line, passing through the winding of relay 14, driver 851, switch contact 2 900, driver 8520
Relay 9 of FIG. 8 operates in the same manner as previously described for relay E in FIG. 6;

   that is to say that the relay 9 will make its armature oscillate in one direction and the other between its contacts 1 and 2 at a frequency which is preferably a sub-harmonic of the frequency of the alternating current (such as only three to five cycles per second for a source of 60 periods) The frequency at which relay 9 oscillates is determined primarily by the settings of autotransformer 825 and potentiometer 826, both including, in fact, a frequency adjustment. The length of time that the armature of relay 9 sticks to its contact 2, compared to the total time that it sticks to its contacts 2 and 1, is adjustable by means of the percentage setting potentiometer, 829.



   Each time relay 9 brings its armature against its contact 2, relay 10 will be actuated by a combination of alternating current and direct current, and will operate at an instant, relative to the waveform of alternating current, which will be determined by adjusting the oscillation start potentiometer, 930.



   Each time relay 10 operates and turns its contact to earth, earth is applied to the winding of relay 1 and by conductor 843 in figure 9. Relay 1 will then operate and will remain energized for. a short time interval following the setting of the pulse stop potentiometer 858, which sets the circuit time constant so that the capacitor 859 acquires sufficient charge to cause relay 1 to drop.



   The various settings including auto transformer 825, frequency potentiometer 826, percentage set potentiometer 829, pulse start potentiometer 820 and stop potentiometer 858 are preferably made. with an oscilloscope connected across resistor 846, so that relay 1 closes its contact when the alternating current waveform crosses zero in one direction and opens its contact when the current waveform AC goes through zero in the other direction, that is to say that the contact of relay 1 will be closed only during half a cycle of alternating current of the chosen polarity, all this as described previously with regard to the relay 1 in figure 7.



   During the operation of relay 1, a circuit is closed from phase 0 of the power line by the contact of relay 15, in parallel with contacts 1 and 2 of relay 16, by conductors 857 and 844 in figure 9 , on the respective right and left sides of the windings of the electromagnets 919 and 917, returning via the respective conductors 850 and 849, to the respective contacts 2 and 1 of the relay 2. It will be noted that the

 <Desc / Clms Page number 17>

 contacts 1 and 2 of relay 2 are short-circuited by means of contact 1 of actuated relay 14.

   Therefore, no matter what position relay 2 may be in, the circuit continues through its armature through resistor 846 and fuse 847 and through contact 2 of relay 14 to the top terminal of inverter 811 which will carry phase # 2 of alternating current energy. Selected half cycles of a specified polarity of the ac energy are, therefore, applied to both electromagnets 917 and 919 to super-magnetize them.



   In the event that the two step switches are not in the positions shown in figure 8, the grounds on conductors 848 and 856 of figure 8 will be extended by the respective slider arms 820 and 824 and by the contacts of the respective stepping magnets SEL 1 and SEL 2 to actuate them. Immediately after being actuated, these respective stepping magnets SEL 1 and SEL 2 open their own actuation circuits, thus releasing and advancing the associated slider arms, one step in the directions shown by the figures. arrows. Note that, for example, the cursor arms 817, 818, 819 and 820 are associated with the stepping magnet SEL 1 and that the cursor arms 821, 822, 823 and 824 are associated with the step magnet. magnet step by step SEL 2.

   Each of these stepper switches continues to advance automatically until it reaches position 22, at which time the earth will be extended by sliders 819 and 823 to the battery through the right windings of the respective relays 7 and 8. These relays 7 and 8 will then bring their armatures into the positions shown, in contact with their respective contacts 1. If the respective step switches are initially in the position shown, the respective relays 7 and 8 will therefore nonetheless. less in the position shown. Note that with relays 7 and 8 in the positions shown, the primary windings of transformers 812 and 808 are short-circuited so that there will be no voltage or alternating current induced in them. secondary of these transformers.



   Magnet switch 900 will now be released in preparation for establishing the circuit for automatic operation, thus releasing relays 15 and 16, removing ground from sliders 820 and 824 of the stepping switches, releasing relay 14 and removing the earth of conductor 838 so as to stop the oscillations of relay 9, etc ...



   To begin the demagnetization process, switches 902 and 904 are placed in their on positions and demagnetization switch 901 is closed. Closing the demagnetization switch performs the following operations: The earth is extended by contact 4 of switch 901 to conductor 938 to start the oscillations of relay 9, etc.



   2. Earth is extended through contact 3 of switch 901 to lead 853 extending in Figure 8 to cause relays 17 and 18 to operate.



   3. Earth is extended through contact 1 of switch 901 to conductor 837 extending in figure 8 and to the battery through the left windings of relays 7 and 8. This does not operate relays 7 and 8. , but will keep them actuated if caused to operate when and if the respective stepping slider arms 819 and 823 ground the terminals 22 of their respective arcs of contact, as previously described.



   4. The conductor 843 of figure 8, which is earthed oha-

 <Desc / Clms Page number 18>

 that once relay 10 is actuated, is extended in figure 9 by the contact of switch 904 to the coil of relay 5 and is extended by contact 2 of switch 901 to conductor 854 returning to figure 8 to l winding of relay 13. Therefore, each time relay 10 is actuated, (actuating relay 1 as previously described), relay 5 will operate to cause the current to operate or release restore value. is applied to the relay in progress and the relay 13 will be actuated to extend a pulse-source earth by its contact and by contact 1 or 2 of relay 6 towards the respective step magnets SEL 2 or SEL 1 at the figure 8.

   As soon as the earth is removed from conductor 843 in Fig. 8, when relay 10 drops out, relays 5 and 13 also drop out, thereby bringing into play the actuation or test release value of the current for the current respectively. relay being tested and allowing the actuated stepping magnet, SEL 1 or SEL 2, to drop to advance the associated stepping switch one position.



   With the relay under test in the position shown in figure 9, that is to say with its armature 720 in contact with its release contact 922, a circuit will have been closed so that the relay 12 of the figure 8 operates and is put in the position shown with its armature in contact with its contact 2. This circuit starts from the battery, passes through the armature 920 of the relay under test, contact 922, resistor 926, conductor 840 through the winding of relay 12, conductor 841, resistor 927 to earth through actuation lamp 929. Actuation lamp 929 will not illuminate in this circuit due to impediments in its circuit. The release lamp 928 will light up, being connected directly to the battery through contact 922 and armature 920 of the relay under test.

   The fact that the release lamp 928 is on indicates the condition of the attempted relay to the operator. With relay 12 in the position shown, earth is removed from its contact 1 and conductor 839, which extends through the contact of switch 902 to relays 3 and 4 in figure 9 and through conductor 855 in figure 8 to the windings of relays 2 and 6.



  These relays 3, 4, 2 and 6, therefore, will be released and in the positions shown in the drawing.



   Under these conditions, a circuit is closed each time Relay 1 is actuated, to apply a reverse polarity (that is to say, the reverse of the magnetization pulses) of al- current energy. This relates to the electromagnet 917 associated with the permanent magnet 925 which comprises part of the release contact 922 of the relay under test.



    This circuit extends from phase 0 of the power distribution line in figure 8, passing through the contact of relay 18, through fuse 847 and resistor 846, the contact of relay 1. resistor 823, the con - tact 1 of relay 2, the conductor 849, by the winding 917 of the electromagnet, the conductor 844, the contact 2 of the relay 17, the cursor arm 822, the cursor 809, the secondary of the transformer 808 and the cursor of the 805 autotransformer, to return to phase # 2 of the line. Note that the polarity of this circuit is reversed with respect to that which was previously described with regard to the part of the process relating to magnetization.

   Due to the fact that the primary of transformer 808 is short-circuited on contact 1 of relay 8 (note that the transformer disconnected or supplied 812 represents a sensibly constant impedance), the only voltage available in this deactivation path is the voltage available to inverter 805, and the small fraction of voltage represented by the position of cursor 809 which is of no particular importance except that it can be set to one position or to

 <Desc / Clms Page number 19>

 the other in order to balance out small differences between transformers, such as 812 and 816 or 808 and 810. At the same time, with the closing of relay 1, as explained before, conductor 843 is set. earth by the operation of relay 10,

   after which relay 5 is actuated by the contact of switch 904. This causes the actuation reset value, current, to be applied to the potentiometer.
909 to the 921 winding of the relay to be tested to ensure that the armature
920 remains in contact with contact 922.



   As soon as the relay 10 drops out, the relay 5 will drop out, thus causing the actuation test value, of the current, to be applied by the potentiometer 906 to the winding 921 of the relay in progress. test. In the meantime, relay 13 has been actuated and released once, causing the SEL 2 stepping magnet to operate and drop once, advancing the associated slider arms one step.



   If the armature 920 of the relay under test does not pass to its contact 923, another demagnetization pulse will be applied to the electromagnet 917 when relay 10 restarts. This demagnetization pulse will be of a slight weight. increased, as determined by the one step advance of cursor 822. Simultaneously with the application of this next demagnetization pulse to the solenoid 917, the relay 5 is reactivated to reapply the value. to restore current actuation, to winding 921 of the relay under test. As soon as relay 10 drops out, relay 5 is released to cause the current actuation test value to be applied to winding 921.

   In the meantime, the stepping magnet SEL 2 is again reactivated and released to cause the associated slider arms to advance yet another step.



   This process continues uninterrupted until the armature 920 of the relay to be tested in response to the application to the coil 921 of the actuation test value of the current moves from its contact. 922 to its contact 923. This causes the release lamp
928 goes out and the actuating lamp 929 lights up. This also makes a circuit is closed, starting from the battery and passing through the armature
920, contact 923, resistor 927, conductor 841, coil of relay 12, conductor 840, resistor 926, to ground through release lamp 928.

   This battery pulse applied to the coil of relay 12, by and above the permanent charge maintained on capacitor 861, is sufficient to cause relay 12 to move its armature from its contact 2 to its contacts 1. and 3. This movement of the armature of relay 12 causes the charge previously acquired by capacitor 833 to dissipate in resistor 835 and causes an earth pulse to be applied by the armature of relay 12, by its contact 3 through the capacitor 834, to the winding of the relay 11, which earth, increasing the load normally carried by the capacitor 860, will cause the relay 11 to operate momentarily until the capacitor
834 can acquire sufficient charge for relay 11 to drop.



   This momentary operation and release of relay 11 opens the circuit between grounded conductor 838 and the bottom terminal of the secondary winding of transformer 803, thereby causing relay 9 to stop oscillating. Earth is also applied by contact 1 of the relay
12 to conductor 839 extending in Figure 9 and through the contact of switch 902 to operate relays 3 and 4 and extending through conductor 855 in Figure 8 to operate relays 6 and 2.



   When releasing relay 11, after a momentary delay, mentioned above, relay 9 can oscillate again to make

 <Desc / Clms Page number 20>

 again that the relays 10, 1 and 5 are operating to cause the application of a demagnetization pulse to the solenoid 919.

   The circuit for this demagnetization pulse goes from phase # 1 of the power supply line through the contact of relay 18, through fuse 847, resistor 846, contact of relay 1, resistor 832, contact 2 of relay 2, conductor 850, winding of electromagnet 919, to return through conductor 857, contact 1 of relay 17, to cursor 818 of the upper step switch and from there to cursor 813, by the secondary of the transformer 812, returning to the cursor of the autotransformer 811.

   The only voltage available in this deactivation pulse circuit is the voltage derived from the slider arm of the autotransformer 811 and the small fraction of the voltage available due to the position of the slider arm 813, due to the fact that the relay 7 short-circuits the primary of transformer 812.



   Because relay 4 is actuated during this demagnetization pulse and because relay 5 is actuated as well, potentiometer 913 will cause the recovery current value to be applied to winding 921 of the current relay. test to force armature 920 to remain in contact with actuation contact 923 of the relay under test. As soon as the demagnetization pulse has passed, as indicated by releasing relay 10, relay 5 will drop out and, in combination with the operation of relay 3, potentiometer 912 will apply to winding 921. of the relay under test the present value of the release test current.

   If armature 920 does not return to contact 922 in response to this release test current value, another demagnetization pulse of slightly increased amplitude is applied to electromagnet 919. This amplitude increased demagnetization pulse is produced because during the operation and release of relay 10, conductor 843 is grounded and detached from earth, which in turn causes relay 13 to operate and then falls. Operation and release of relay 13 causes an earth pulse to pass through its contact and contact 2 of relay 6 to the winding of the stepping magnet SEL 1, after which the stepping magnet SEL 1 operates and falls, causing the associated cursor arms to step forward.



   This process continues with armature 920 in contact with actuation contact 923 until armature 920 switches to release contact 922 in response to the prescribed release test current value. , after which relay 12 is actuated again to cause the armature to make contact with its contact 2. This momentarily actuates relay 11 to stop the oscillation of relay 9 which stops the application of demagnetization pulses. to the electromagnets and releases the relays 3, 4, 2 and 6 to return the relay control circuit to the state described previously, so that new demagnetization pulses can be applied to the electromagnet. magnet 917.



   The process described above is repeated back and forth with respect to electromagnets 917 and 919 until a point is reached where armature 920 moves back and forth between contacts 922 and 923 immediately. in response to the respective application of the values of the release and actuation test currents. This will cause relay 12 to oscillate similarly back and forth between its contacts 2 and 3 so that a succession of earth pulses is applied to the winding of relay 11 at a frequency high enough to keep relay 11 actuated continuously. The continuous operation of relay 11 immobilizes the demagnetization process by causing the re-

 <Desc / Clms Page number 21>

 left 9 stops oscillating.

   The rapid flashing of the two lamps 928 and 929 gives a visual indication to the operator that the relay under test is correctly set.



   As soon as the magnetization switch 900 is actuated with the demagnetization switch 901 released at the start of setting a new relay, the two stepping mechanisms in figure 8 will automatically adjust themselves to their positions. normal starting points.



   We will now give some indications which will facilitate the reading of the drawings: - In figure 1, D means demagnetization.



   M at the beginning (by hand).



   FA final stages (automatic).



   With actuation.



   The liberation.



   CS selector switches
II 1/2 cycle pulses.



   CAL actuation-release control.



   CDE test-demagnetization control. th try, r recovery.



   R relay under test.



   CB coil current.



   EM electromagnet, mounted.



   AP permanent magnets.



  - In figures 4 and 5, S = sequence of adjustments.



   AT = ampere-turns.



   SBA = actuation sensitivity.



   SBL = "release ve = test values.



  - In figure 6, GR = coarse, F = fine. re = gearboxes. p = polarized.



   A and L have the meanings of figure 1. a = magnetization - d = demagnetization - de = release.



  - In Figures 8 and 9:
AE = actuation test.



   AR recovery of actuation.



   THE liberation test.



   LR release recovery. m walking.

 <Desc / Clms Page number 22>

 th test. r recovery. p polarized.



   R relay to try. f actuation.



   1 release # # (in figure 8) = same phase.



   R actuation.



   CLAIMS
1. Circuit for automatically adjusting the permanent magnet polarization of a pole relay, characterized in that it comprises a circuit responding to a switch having at least two positions, in the first of which the control circuit is brought to. connecting a source of magnetizing current pulses to a coil magnetically coupled to the permanent magnet, the amplitude of these pulses being such that they over-magnetize the permanent magnet, and in the second of which the control circuit is brought in connecting to the coil a source of variable demagnetization current pulses of gradually increasing magnitude,

   the control circuit also selectively connecting to the actuating coil of the polar relay a source of restoring current of sufficient magnitude to maintain the armature of the relay on the deactivated contact during the application of the demagnetization pulses or connecting during the intervals between the pulses a source of test current of the magnitude necessary to release the armature from this contact when the relay is correctly set, and a detector responding to the movement of the armature is moving away from the contact to cause the control circuit to complete the series of demagnetization pulses.


    

Claims (1)

2. Circuit according to Claim 1, in which the polar relay is a relay having two contacts, each with a permanent magnet, characterized in that a detector is provided for each contact, the control circuit being such that operation of the first detector to indicate release of the armature of the first contact causes the control circuit to apply demagnetization pulses to the demagnetization coil associated with the second contact and operation of the second detector to indicate that the armature has left the second contact causes the control circuit to re-apply demagnetization pulses to the demagnetization coil associated with the first contact, demagnetization pulses thus being finally applied to both demagnetization coils until the detectors indicate immediate release from each contact in turn, when adjustment is complete. 3. Circuit according to claim 1 or 2, characterized in that the variable demagnetization pulses are produced by a potentiometer which can be varied continuously and by an autotransformer which can vary continuously, which is supplied. alternating current, the control circuit choosing only half cycles of one polarity. 4. Circuit according to claims 1, 2 or 3, characterized in that the application to the coil or coils of demagnetization pulses is commanded or controlled by a beating relay. <Desc / Clms Page number 23> 5. Circuit according to claim 4, characterized in that the operation of a detector to indicate the movement of the armature has the effect of deactivating the beating relay. 6. Circuit according to any one of the preceding claims, characterized in that the application of the test and reset currents is controlled by a pair of relays.