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Showing papers on "Relay published in 1968"



Journal ArticleDOI
TL;DR: In this article, the authors describe the factors involved in applying underfrequency relays to achieve a desired "deficient generation" protection level and a calculating method to achieve optimum relay settings.
Abstract: During severe emergencies which result in insufficient generation to meet load, an automatic load shedding program throughout the affected area can prevent total area collapse. It also helps to achieve fast restoration of all affected loads. This paper describes the factors involved in applying underfrequency relays to achieve a desired "deficient generation" protection level and a calculating method to achieve optimum relay settings.

134 citations


Patent
Robert G Dale1, Gary V. Fay1
19 Jul 1968
TL;DR: In this paper, a relay and triac are connected in series with the AC source and the load, and circuit means are connected between a gate electrode of the triac and circuit input terminals to which the source is connected.
Abstract: Disclosed is circuitry for controlling the flow of current from an AC source to a load and includes a bilateral semiconductor switch such as a semiconductor triac connected in parallel with the contacts of an electromechanical relay. The relay and triac are connected in series with the AC source and the load. Circuit means are connected between a gate electrode of the triac and circuit input terminals to which the AC source is connected and provides turn-on gate current for the triac prior to and during the closure of the electromechanical relay contacts to prevent effects of contact bounce. This circuit means also provides a sustaining or hold current to the triac subsequent to the opening of the relay contacts and thereby prevents contact arcing. The triac conducts before the relay contacts close and after the relay contacts open.

61 citations


Patent
22 Mar 1968
TL;DR: An automatic lamp disconnecting system for vehicle lighting systems having a lamp energizing circuit including a normally open relay switch in series with a manual lamp control switch was presented in this article. But the relay switch was not considered in this paper.
Abstract: An automatic lamp disconnecting system for vehicle lighting systems having a lamp energizing circuit including a normally open relay switch in series with a manual lamp control switch. Magnetic means for closing the relay switch is energized through the vehicle ignition switch and through a separate holding circuit comprising, in series connection, the relay switch, the lamp control switch, and a normally closed thermal time delay switch which has a heating element responsive to energization of the vehicle lamp only when the ignition switch is opened to effect opening of said time delay switch a predetermined time after opening of the ignition switch.

41 citations


Patent
12 Jul 1968

24 citations


Patent
10 Oct 1968
TL;DR: In this article, a relay controlled alternating current load circuit with relay switch contacts connected in series with the load across the alternating current source is provided with a bilateral thyristor triode connected in parallel with the switch contacts and gated through the relay coil.
Abstract: A relay controlled alternating current load circuit having a set of relay switch contacts connected in series with the load across the alternating current source is provided with a bilateral thyristor triode connected in parallel with the switch contacts and gated through the relay coil and a control switch connected in series to one side of the alternating current source for arc suppression

24 citations


Journal ArticleDOI
01 Feb 1968
TL;DR: In this paper, a phase comparator with a polarised-mho characteristic is presented, and a minimum inherent operating time of one halfcycle of the power frequency can be defined for this comparator arrangement and both the static and dynamic operating characteristics are predictable over the whole working range.
Abstract: The ease with which transistor comparators for distance relays can be designed for high-speed operation must be tempered with consideration of overall performance and integrity of operation. Operating speed must be defined over the whole of the working range of the relay, and neither the speed nor the measuring accuracy should be unduly affected by the severe transients generated by modern e.h.v. networks. The comparator, as well as being proof against damaging voltage surges, must operate accurately in the presence of long-duration offset transients accentuated by low-loss modern-plant parameters and the random point-on-wave inception of faults due to natural hazards and closure or reclosure of modern pressure-head circuit breakers. The attainment of high-speed operation under these practical conditions precludes the adoption of many, apparently practical transistor-comparator circuits and favours the adoption of circuits with well defined dynamic performances.Extensive laboratory investigation has shown that the block-average comparison principle is amenable to precise design in all respects, and practical fast-operating relays can be designed with good transient-free characteristics. The results obtained on such a practical relay are presented in the paper for a phase comparator with a polarised-mho characteristic. It is shown that a minimum inherent operating time of one halfcycle of the power frequency can be defined for this comparator arrangement and that both the static and dynamic operating characteristics are predictable over the whole working range. Equivalent performance for the amplitude-comparator counterpart is justified in an appendix, and underlines earlier work.Relays using the block-average comparison principle have been used successfully in field trials since 1957, and this principle now forms the basis for various production designs. Sufficient field experience is now available to justify the theoretical analysis and laboratory test results given in the paper.

22 citations



Journal ArticleDOI
01 Mar 1968
TL;DR: In this article, a sampling technique has been developed which allows a comparison of instantaneous values derived at different instants of time, thereby dispensing with the need to phase shift or mix signals derived from the primary line quantities.
Abstract: A sampling technique has been developed which allows a comparison of instantaneous values derived at different instants of time, thereby dispensing with the need to phase-shift or mix signals derived from the primary line quantities. Both amplitude and phase comparisons are used to derive a variety of impedance characteristics. The relays combine high sensitivity with a high resistance to interference. Detailed results are presented for a current-polarised relay with a characteristic surrounding the probable fault area.

16 citations


Patent
04 Apr 1968
TL;DR: In this article, the relay station selects the fields of special user information for transmission to the special receivers and also substitutes for such fields adjacent fields of general user information so that a continuous stream of GUs can also be transmitted to the plurality of general information receivers.
Abstract: A television system includes a central television transmitter, a relay station, a plurality of general information receivers and a plurality of special receivers. The central transmitter transmits at least fields of general user information interplexed with fields of special user information to the relay station. The relay station selects the fields of special user information for transmission to the special receivers and also substitutes for such fields adjacent fields of general user information so that a continuous stream of general user information can also be transmitted to the plurality of general information receivers.

14 citations



Patent
21 Oct 1968
TL;DR: In this paper, a double-throw transfer switch was used to couple a magnetic lutch relay and a capacitor to a movable contact of the relay in a shift register circuit.
Abstract: Shift register circuits in which each register stage comprises a magnetic lutch relay and a capacitor adapted to be coupled to a movable contact of said relay through a double-throw transfer switch, two stationary contacts of said relay being connected respectively to a reference potential and a first power source of a first potential, coil of said relay having one end connected to a second power source of a second potential lower than said first potential and the other end adapted to be coupled to the capacitor in the immediately preceding stage through the double-throw transfer switch in the immediately preceding stage.


Patent
12 Aug 1968
TL;DR: In this article, an apparatus for sensing drowsiness of an operator of a motor vehicle which includes a multiple contact sensing switch coupled to or actuated by movement of the steering mechanism of the motor vehicle, means for maintaining a predetermined charge on a condenser in a relay time constant circuit under one condition of motor vehicle operation, and means for discharging said condenser at a predetermined rate if the mode of steering the vehicle is changed, and alarm means acteduated by said relay when the condenser''s charge level reaches a predetermined level and the output of a generator mechanically coupled
Abstract: The invention relates to apparatus for sensing drowsiness of an operator of a motor vehicle which includes a multiple contact sensing switch coupled to or actuated by movement of the steering mechanism of the motor vehicle, means for maintaining a predetermined charge on a condenser in a relay time constant circuit under one condition of motor vehicle operation, means for discharging said condenser at a predetermined rate if the mode of steering the vehicle is changed, and alarm means actuated by said relay when said condenser''s charge level reaches a predetermined level and the output of a generator mechanically coupled to the vehicle drive means and electrically coupled to the alarm circuit exceeds a predetermined voltage. The output of this generator increases with an increase in road speed of the vehicle. An alarm relay placed in series with the time delay relay contacts controls the operation of the alarm signal. The pull in voltage for this relay is selected so that only when the vehicle reaches a certain selected minimum speed will it be possible to have the alarm relay actuate. It will actuate at any speed above the minimum speed if the driver does not actuate the steering wheel within the time delay interval.


Patent
03 Dec 1968
TL;DR: In this paper, an AC enable gate circuit is proposed to perform logic gating in binary data signal systems and interlocking relay functions in safety monitoring systems, which is adaptable to perform diverse functions in which failsafe properties are desired.
Abstract: A novel electronic switching circuit is operated as an AC enable gate circuit which is adaptable to perform diverse functions in which failsafeness is desired. These functions include logic gating in binary data signal systems and interlocking relay functions in safety monitoring systems. The switching circuit construction yields an enable gate circuit operation mode which relies upon two dynamic signals to thereby provide virtually total failsafeness. The gate switching is performed by actuating an active amplifying device between its ENERGIZED and DEENERGIZED states to provide the OPEN and CLOSED enable gate circuit conditions, respectively. A gate actuation signal input network of the circuit derives the device energizing signal in response to a dynamic actuation signal, which is one of the dynamic signals relied upon for failsafe properties. The enable gate channel of the circuit is of a construction which passes only a dynamic, or AC carrier signal above a predetermined threshold. The carrier signal is the other of the dynamic signals relied upon for failsafe properties. The AC carrier is amplified and then attenuated in its passage through the enable gate channel to cooperate with a thresholding in other circuits which may be connected in cascade.

Journal ArticleDOI
01 Jan 1968
TL;DR: In this paper, an evaluation of the protection coverage afforded by earth and phase-fault distance relays in terms of the range of apparent impedances presented to them for which the protection correctly operates and initiates circuit-breaker tripping is presented.
Abstract: The paper is devoted to an evaluation in detail of the protection coverage afforded by earth- and phase-fault distance relays in terms of the range of apparent impedances presented to them for which the protection correctly operates and initiates circuit-breaker tripping. This requires a knowledge of both the effective polar characteristics of relays for specified system-fault conditions and also, for the same conditions, the apparent impedance to which the relays respond. Owing to the wide variation encountered in both of these in practice, the ordinary static characteristics of relays provide only a limited indication of the discriminative properties of distance relays in different applications, but it is shown how a comprehensive assessment may be made. In particular, investigations are described of the performance of mho relays when applied to 132kV and 400kV circuits, and the results of the investigations are summarised. The studies include the response to faults within the protected zone, the discrimination against external reverse faults, against healthy-phase relay operation and, on double-circuit-line constructions, the discrimination against healthy-circuit relay operation. The time response of comparators in impedance measurement is introduced, and it is explained how, evolving from this, the coverage afforded by the protection may be directly related to its operating time. In this way a basis is provided on which the operating time of distance relays may be systematically linked to its discriminative properties.

Patent
04 Nov 1968

Patent
19 Dec 1968
TL;DR: In this paper, a manually operable switch is operated to render conductive a first bidirectional current-conducting semiconductor device in a sensing circuit when a load is connected between output terminals to condition a power application circuit for supplying alternating current to the output terminals and to energize a relay and close contacts to complete the power application circuits to the load.
Abstract: A manually operable switch is operated to render conductive a first bidirectional current-conducting semiconductor device in a sensing circuit when a load is connected between output terminals to condition a power application circuit for supplying alternating current to the output terminals and to energize a relay and close contacts to render conductive a second bidirectional current conducting device and to complete the power application circuit to the load. Disconnection of the load from the terminals return the bidirectional current conducting semiconductor devices to a nonconductive state and disables the load sensing and power application circuit until a load is connected across the terminals and the switch is operated.


Patent
Andrew F Deming1
30 Apr 1968
TL;DR: In this article, a remotely controlled radio receiver circuit which may be used to control a garage door operator, for example, from a low-power remote transmitter, is described, where a first time delay capacitor is connected in a circuit to give only time delay of turn turn-on of a load relay, and a second time delay capacitance was connected in circuit, and in this manner telemetering or other relatively rapid pulsed signals, even of the proper carrier and audiofrequencies, do not actuate the relay.
Abstract: The disclosure shows a remotely controlled radio receiver circuit which may be used to control a garage door operator, for example, from a low-power remote transmitter. The signal emitted by the transmitter includes a carrier as modulated by a lower frequency, for example an audiofrequency, which signal is amplified in the receiver, detected and supplied to an audiofrequency resonant load and to a resistance load. These two loads are connected in opposition so that if the received signal is of the proper carrier frequency to be amplified and passed through the first stages of the receiver and if the audiofrequency is of the proper preselected frequency to be resonated by the audiofrequency resonant circuit, a resonant voltage signal is passed. A first time delay capacitor is connected in a circuit to give only time delay of turn turn-on of a load relay, and a second time delay capacitor is connected in circuit to give only time delay of dropout of the relay, and in this manner telemetering or other relatively rapid pulsed signals, even of the proper carrier and audiofrequencies, do not actuate the relay. The foregoing abstract is merely a resume of one general application, is not a complete discussion of all principles of operation or applications, and is not to be construed as a limitation on the scope of the claimed subject matter.

Patent
09 Jul 1968

Patent
01 Oct 1968
TL;DR: In this paper, relay operated switch switches are used for programmating a regulated power supply system using a control bridge circling circuit, and adjustments to compensate for the switch resistances are made.
Abstract: RELAY OPERATED SWITCHES ARE PROVIDED FOR PROGRAMMING A REGULATED POWER SUPPLY USING A CONTROL BRIDGE CIRCUIT. BIRDGE CURRENT AND VOLTAGE CONTROL RESISTORS ARE DIGITALLY SELECTED ADJUSTMENTS TO COMPENSATE FOR THE SWITCH RESISTANCE ARE USED FOR IMPROVING ACCURACY IN SUCH A CONFIGURATION.

Patent
12 Apr 1968
TL;DR: In this paper, the variations in capacitance to ground of an antenna due to proximity or remoteness of a person or object causes variations in the output of an oscillator, and the oscillator output decreases or increases (respectively) and thereby causes switching circuitry to energize or deenergize both of two relays, thus causing energization of a load.
Abstract: The variations in capacitance to ground of an antenna due to proximity or remoteness of a person or object causes variations in the output of an oscillator. In one embodiment, when antenna capacitance either increases or decreases with respect to a predetermined level, the oscillator output decreases or increases (respectively) and thereby causes switching circuitry to energize or deenergize (respectively) both of two relays, thus causing energization of a load. At the normal antenna capacitance, one relay is energized and the other is deenergized, and the load is deenergized. In a second embodiment, the same load-controlling functions are achieved with a circuit employing a single relay.

Patent
12 Jun 1968
TL;DR: In this paper, a relay is employed which has normally open contacts and normally closed contacts, and a solenoid for actuating the camera release button is employed for camera release.
Abstract: A relay is employed which has normally open contacts and normally closed contacts. A first series electrical circuit is formed from a source of electrical power through a manually operable switch, the normally closed contacts, and a solenoid for actuating the camera release button. A second series electrical circuit is formed through the relay coil, the flashlight contacts of the camera (which are closed when the shutter is operated) and the source of power. A capacitor and adjustable resistor are connected in series across the relay coil. The normally open relay contacts are connected in a series circuit with a signal light and the source of power.

Journal ArticleDOI
TL;DR: In this paper, it was shown that conditions which guarantee that a relay system will have no symmetric periodic solutions are also sufficient to insure the absolute stability of the origin of the relay system.
Abstract: The global asymptotic stability of third-order relay control systems with real, nonpositive eigenvalues is related to conditions necessary for the existence of periodic solutions of such systems. By application of Popov's theorem it is shown that conditions which guarantee that a system will have no symmetric periodic solutions are also sufficient to insure the absolute stability of the origin. This result allows a relay system to be designed by choosing the switching function subject to the constraint that the switching plane avoid a certain easily defined region of state space.

Patent
05 Dec 1968
TL;DR: In this paper, a turn signal system is described, which includes a turn signal switch for CONTROLLING ACTUATION of one or both ARMMs of a DUAL ARMATURE RELAY to ENERGIZE the APPROPRIATE TURN SIGNAL LAMPS.
Abstract: A TURN SIGNAL SYSTEM IS DISCLOSED WHICH INCLUDES A TURN SIGNAL SWITCH FOR CONTROLLING ACTUATION OF ONE OR BOTH ARMATURES OF A DUAL ARMATURE RELAY TO ENERGIZE THE APPROPRIATE TURN SIGNAL LAMPS. ONE OF THE RELAY ARMATURES CARRIES A SWITCH OPERATING GEAR WHICH IS ADAPTED TO BE COUPLED TO THE ODOMETER DRIVE MECHANISM OF THE VEHICLE TO OPEN THE CIRCUIT TO THE RELAY AND DENERGIZE THE SIGNAL LAMPS AFTER THE VEHICLE HAS TRAVELED A PREDETERMINED DISTANCE.


Patent
03 Jan 1968
TL;DR: In this paper, the charging current to a battery is controlled in dependence of the rate of change of battery voltage, which is measured by a volt meter which gives an indication of the change of voltage.
Abstract: 1,097,451. Battery charging systems. D.P. BATTERY CO. Ltd. June 10, 1965 [March 11, 1964], No. 10331/64. Heading H2H. The charging current to a battery is controlled in dependence of rate of change of battery voltage. The charging current is arranged in three stages. In the first, the output of a bridge 23-26 is applied to capacitor 30 which is periodically connected through contacts 9/1a, 9/1b operated by a timer 9 in a cycle of about five minutes, to the input of a D.C. amplifier 32. When a Zener diode 28 breaks down on the battery voltage rising to say 2.3 volts per cell the bridge output is reversed and the amplifier 32 operates a relay 1 which is held by standing current until de-energized by timer contacts 9/2. Operation of relay 1 energizes a relay 3 and hence a relay 6 which initiates stage 2. Capacitor 30 is again periodically connected to the amplifier in series with another capacitor 31 which is charged after a number of cycles to approximately the voltage of the capacitor 30 on the previous cycle. On the next occasion the relay 1 is operated through timer contacts closing, the relay 4 is operated and held through coil Y, relay 8 also being maintained energized through contacts 4/2. So long as the battery voltage continues to rise the relay 1 will be energized each timer cycle, but when the change of voltage is insufficient to cause the relay 1 to be energized the relay 4 is released by the opening of timer contacts 9/4 hence the next time contacts 9/3 open, the relay 8 is released, contacts 8/2 breaking the charging supply circuit, and contacts 8/1 energizing relay 5 which is held through coil Y and contacts 5/1. Contacts 5/3 change the bridge series resistance from 21 to 22 and contacts 5/4, 5/5 reverse the input to the capacitor 30. Contacts 5/2 opening releases relay 6 hence contacts 6/1 shunts capacitor 31 and reconnects the capacitor 30 directly to the amplifier input. The resistor 22 passes an increased current through the bridge so that the Zener diode 28 breaks down at a lower battery voltage. When the battery voltage drops te say 2.2 volts per cell the Zener ceases to conduct hence the next time contacts 9/1A, 9/1B change over, relays 1, 4 and 8 are energized until broken by contacts 9/4, after say four minutes, after which the cycle is repeated when the battery voltage again falls. If the battery is disconnected a potential divider 36 and Zener diode 38 causes a transistor 37 to conduct energizing a relay 2 and disconnecting the supply through contacts 2/1 and relay 8. In an alternative arrangement the capacitors are eliminated and the resistance 22 is replaced by a motor driven rheostat which is advanced each time the relay 1 is operated. The circuit may be modified by replacing the relay 1 by a volt meter which gives an indication of rate of change of voltage. Alternatively the amplifier output may be connected to a null reading potentiometer or to a computer giving a continuous indication of battery performance.