Showing papers on "Relay published in 1980"

Automatic light control for automotive vehicles

Abstract: An automatic light control for automotive vehicles includes a relay connected to a power source by way of a main switch and an electronic switch, and a control circuit for on-off control of the electronic switch. In the control circuit, a brightness sensor produces a signal representing the ambient brightness which is compared with a predetermined reference signal by comparator means. The electronic switch is turned on or off in response to the difference in output of the comparator means to energize or deenergize the relay to thereby turn the vehicle lights on or off. The control may include two main light control circuits of identical configuration arranged in parallel, each of which serves as a back-up circuit for the other, and a monitor circuit adapted to issue an alarm when the two circuits produce unequal outputs.

Minimum size, integral, A.C. overload current sensing, remote power controller

Abstract: An A.C. overload current sensing, remote power controller of minimum size and weight and integral construction. Current rate sensing wound toroids are used that are small enough to fit around the line terminal studs without having to enlarge the prior insulator space available therein. The electronic overload current detecting and tripping control circuit is replaced by a pair of modules, detector and control modules, having improved performance and a shape and size such that they fit within the relay housing alongside its operating magnet. The detector module has integrator means for converting current rate of change signals into current magnitude indicative signals thereby enabling use therewith of rate sensing wound toroids of about one-tenth the size of equivalent current transformer wound toroids. It fully meets the calibrated step function overload trip time requirements while also providing protection for unusual overload conditions such as varying overloads including pulse accumulation effects or repetitive reset, and simulates the response of a thermal element to prevent excess heating of the wire or load that it is protecting under any overload conditions. Moreover, one version of the control module incorporates a single standard CMOS IC logic element that provides a digital solution to the combinations of control conditions requirements while at the same time reducing the number of conventionally-required cutthroat contacts from two to one and isolating the control input from the relay power circuit. Another version provides reset lockout.

Digital Programmable Time-Parameter Relay Offers Versatility and Accuracy

Abstract: The authors have developed, implemented, and tested an improved time-parameter relay The relay principles are suitable for all time-overcurrentli- applications, and are also suitable for any time-parmeter function Specific advantages include: protection of multiple phase; high accuracy, especially for long operating times; inclusion of a reclosing relaync - function; any time-parameter curve characteristics; and straightforward implementation of input parameter- metering The relay hardware is essentially an analog- to-digital conversion scheme followed by a dedicated microprocessor which processes samples of the input quantity in accordance with the principles and algorithms described in this paper The magnitude of the input quantity, which is assumed to be an AC voltage or current, is determined from four samples per cycle DC components of the input quantity are ignored However, the relay could be adapted to DC applications by simple modification of the magnitude estimating functions The accurate long-time characteristics and the selectable reset characteristics suggest this relay is especially applicable to the protection via thermal characteristic emulation of electrical equipment, such as motors or cables, from overheating

Automatic balancing system for exchange

Abstract: PURPOSE:To realize the automation while avoiding a big recrease of the cost for the exchange by combining the automatic balancing operation with the program control via the central control unit. CONSTITUTION:When the subscriber number along with the information of the impedance measurement are thrown into central control unit 26 from input/output device 24, test relay contacl t in line circuit 14 switches subscriber lines 12 and 12' to selective connection unit 20. At the same time, line 12 and 12' are connected to impedance measuring device 34. The impedance measured is transmitted to unit 26 to decide the optimum balancing network value. And the relay selection signal is given to signal distributor 30 to energize, for example, relay N1, and thus relay contact n1 is closed in 2-wire/4-wire converter circuit 16. And balancing network BN1 is connected to hydrid coil HYB.

Method and apparatus for relaying signals between a ground station and a satellite using a ground relay station

Abstract: In satellite communication systems it is often necessary to relay the signal between terminal stations and the satellite through ground relay stations remote from the terminal stations. Normally, in systems using composite multi-carrier signals for transmission through the satellite, the composite multi-carrier signals are reduced to baseband in the ground relay station prior to retransmission. To reduce the amount of equipment and the cost of such a ground relay station, a method and apparatus for relaying the composite multi-carrier signal through the ground relay station without reducing it to baseband in the ground relay station is provided. Thus, with this arrangement, the composite multi-carrier nature of the signal is preserved throughout the ground relay station.

Power factor control system

Abstract: A control system for automatically adding and subtracting capacitors to and from an electrical supply line for regulating the power factor of the supply line. A three-phase transducer is connected to the supply line and supplies a signal in direct proportion to the VARs of the supply line to a double setpoint meter relay. The meter relay is connected to a pair of timing relays which are selectively energized in response to a capacitor "add" or "subtract" signal from the transducer. If the signal is maintained for a predetermined period of time on one of the timing relays, a motor of a respective "add" or "subtract" cam-actuated switch is activated. The cam switches are programmed to energize or deenergize control relays, which in turn actuate capacitor contactors to add or subtract the next available capacitor. The cam switches are in independent circuits so that the cycling of each capacitor is in a next-one-available cycle, whereby the first capacitor added is the capacitor which was removed the longest from the supply line, and the first capacitor removed is the capacitor which has been energized the longest. This sequence provides uniform usage of all the capacitors and the associated controls.

ROM Controlled protective relay system for power transmission network

Abstract: A digital protective relay system includes a read only memory (ROM) in which a program for executing calculations on a judgment formula for a predetermined protective relay function is stored. Switching of the judgement formula, from one form (e.g., over current protection) to another form (e.g., undervoltage protection), is facilitated by a setting unit and an operation mode switching unit which permit changing of judgement formula constants without changing the ROM program. The setting is used to input desired relay operation threshold values. The operation mode switching unit is used to specify the kind and sign of constants contained in a predetermined term in the judgment formula and also the kind of inequality in the formula. A digital data processing unit performs protective relay calculations by applying input data obtained from the power transmission system, which data has been pre-processed by an A/D converter and related circuitry and stored in a data memory, to a relay operation decision formula determined by the data stored in the ROM, the setting unit, and the operation mode switching unit.

Self-checking safety switch control circuit

Abstract: The present invention relates to a self-checking safety switch control circuit for a power combustion system. The circuit comprises a safety switch, a combustion blower relay, a thermal pilot switch, and a fuel supply system. The safety switch operates to detect flow through the combustion system. The safety switch either operates the pilot switch directly or operates the fuel supply system directly to shut down the system if no flow through the combustion system is detected. The circuit has a self-checking feature because combustion cannot be initiated in a subsequent cycle of the system if the safety switch remains in the proven condition from the previous combustion cycle.

Main station connection system of key telephone system

Abstract: PURPOSE:To make it possible to connect easily a main station in a key telephone system not by making the connection of the main station by a mechanical main-wire acquisition switch but by discriminating by the acquisition signal of the main station whether or not the connection is possible. CONSTITUTION:When hook switch 24 is closed by lifting the handset of main station 3, its channels 21 . 22 are connected to directcurrent supply resistances 10 and 11 by contacts 4b-1 and 4b-2 and hook switch detection circuit 29 operates by the information to send out its signal to main-wire acquisition switch 7-1 via line 30. Therefore, the signal is sent, with switch 7-1 closed, to main-wire acquisition holding circuit 31 in parpllel to control part 6, thereby resetting relay 4b. As a result, main station 3 is connected to main wires 8 . 9 by contacts 4b-1 and 4b-2 via relay 5b to make contact 5b-1, thereby maintaining a main-wire acquisition state until the call ends.

Electric iron stand with time delay safety switch arrangement

Abstract: A stand for an electric iron incorporates an automatic time delay safety switch arrangement which reduces the chances of fires being started by an unattended iron and serves to save a substantial amount of electric energy by cutting off the current to the iron when it is left turned-on but unattended. The stand includes a hinged, spring biased platform of insulating material for supporting an electric iron during non-use periods. Placement of the iron on the platform causes the platform to pivot closing a normally open switch. Closure of the switch energizes a standard electrically energized time delay relay mounted on the platform. After lapse of a predetermined time period, the time delay relay actuates a manually resettable electric relay from a first condition allowing the electric iron to be energized from a power supply socket on the platform to a second latched condition whereby the iron is deenergized. Should the iron be removed from the platform before the lapse of the predetermined time period, the iron remains energized and the time delay automatically resets itself for the next placement of the iron on the platform. Actuation of the resettable relay to its second position also causes the time delay means to be automatically reset. However, a manual reset button on the resettable relay must be actuated to return the resettable relay to its first condition from the second condition to again energize the iron.

Control system for dual coil pilot valve burner system

Abstract: There is disclosed a control system for a gas burner appliance having an interrupted pilot burner operation. The system employs serially-connected first and second (main) electromagnetic operated valves. The first valve has a dual coil construction with a hold coil which can retain the pilot valve open and a pick coil which, acting in concert with the hold coil, can move the first valve to its open position. The control system utilizes one double pole, double throw relay in circuit with a lockout switch, the voltage source, the thermostat switch, and the cold switch contact of the flame switch. The igniter and pick coil are in circuit to the normally open contact of the relay thus being deenergized after a flame is detected at the pilot burner. The coil of the main gas valve is in circuit with the voltage source, the thermostat switch, the normally closed contact of the relay and the hot contact of the flame switch. The hold coil of the first valve is in circuit with the voltage source and the thermostat switch. The system is also provided with a serially-connected lockout switch with its heater in the relay coil circuit. A protective fuse and fuse blowing circuit is also provided.

A Software Design for a Computer Based Impedance Relay for Transmission Line Protection

Abstract: The design of a computer based impedance relay is discussed and a multi-function approach is proposed which incorporates metering, fault arcniving and frequency monitoring. Results from a prototype installation are presented.

Data relay system

Abstract: A data relay system transmits addresses from a host device sequentially to each of a plurality of data relays and for transmitting data sequentially through each of the plurality of data relays to the host device. Serial addresses are placed on the data bus by the host device and received by a Signal Conditioner in the data relay and passed through an Address Parallelizer and Address Selector. If the address is recognized by the Address Selector, then a Data Group is counted by the Data Group Counter while the Data Group is enabled. The enabling of a selected Data Group will result a selected parallel data being supplied to the Data Group Serializer which present the parallel data for serial transmission to the host device.

Remotely-controllable relays

Abstract: A ripple control relay is arranged (i) to delay implementation of a received command until the end of a predetermined time interval following reception of the command; (ii) to delay implementation as in (i), and to implement the complementary command automatically after a further predetermined interval; or (iii) to repeat the sequence as in (ii) cyclically.

Circuit arrangement for monitoring and controlling closing and opening movements

Abstract: Closing and opening movements are effected by a reversible motor M. The motor M receives its power from a supply U via a feed circuit which includes switch contacts r 1 , r 2 controlled by a relay R. The arrangement is such that a closing movement takes place when the relay is energized and an opening movement when the relay is deenergized. To select these two movements there is provided a selector switch S in the feed circuit which has two operative positions and an intermediate neutral position. The excitation winding of the relay R is included in a monitoring circuit in parallel with a strip-like safety switch SL. The strip-like safety switch SL is positioned in the path of the closing movement and has two strip-like contact bands 1, 2 which are pressed together if an object should become trapped in the path of the closing movement. If this occurs the excitation winding of the relay is short circuited and it automatically reverses the motor to convert the closing movement into an opening movement. A follower contact F is associated with the selector switch S and serves to short circuit the monitoring circuit during the opening movement so that it is only connected operatively in parallel with the feed circuit during the closing movement. The series arrangement of the contact strip 1, the excitation winding of the relay R and the contact strip 2 means that a breakage in either of the contact strips, i.e. a faulty safety sensor, will prevent potentially dangerous closing movements from taking place. A number of alternative embodiments are shown including variations using DC, single phase and three phase motors.

Control circuit for vehicle turn-signal flasher systems

Abstract: A control circuit for the turn-signal flasher system of an automotive vehicle. The flasher system includes a relay having switch contacts which are serially connected, together with a direction indicator switch, between the vehicle battery and the turn-signal lamps. A measuring or sampling resistor is connected between the battery and the relay contacts. First and second pulse generators are connected between a first voltage indicator and the relay coil, and are selectively gated to interrupt the relay during normal lamp load conditions. The first pulse generator provides a normal mark-to-space ratio whereas the second pulse generator provides a reduced mark-to-space ratio for use during night driving conditions. Third and fourth pulse generators are responsive to corresponding voltage indicators connected to the measuring resistor. The third and fourth generators function to respectively provide different mark-to-space ratios in response to, and indicative of, lamp outage or current-overload conditions.

Solid state self-checking relay

Abstract: A solid state relay is disclosed which is failsafe in the sense that it is prevented from failing in a closed circuit condition. The relay comprises a main switch adapted to be connected in series with a load and voltage source and responsive to relay opening and closing signals. A secondary switch is connected in parallel with the load and is switched a sense opposite that of the main switch by the relay opening and closing signals. If the main switch fails to open, the secondary switch is closed and the load is short circuited by it. Additionally, a fuse in series with the main switch is blown by the current through the secondary switch to latch the relay in the open circuit condition. Self-checking circuits are provided to latch the relay an open circuit condition if there is any circuit failure.

Remote power switching circuit for TV or radio - has rechargeable power source for initial relay operation in transistor control circuit

Abstract: The power is switched using relay contacts in the mains supply circuit to the equipments power supply circuitry (5). The circuit does not rely upon a stand-by mains power feed to operate the remote control switching. Whilst the equipment is in operation one output feed (U1) from the power circuit (5) is used to recharge a battery (8). Transmitting an 'ON' signal from the remote control (9) causes the receiver (6), powered by the battery (8) to feed a "turn-on" voltage via a potential divider circuit (11,12) to a switching transistor (13). This allows current to flow in the relay coil (4) to operate the mains contacts (3). A relay (4) holding current is obtained from the power supply (5). Operating the manual switch (1) with its ganged contact (2) also passes a turn on voltage through to the switching transistor (13) to operate the holding relay (4). Turning off is accomplished by turning off and blocking the controlling transistor (13).

Development of New Relays With Significantly Improved Performance Against Badly Distorted Transient Waveforms

Abstract: A series of new relays with excellent distortion-tolerating characteristics was successfully developed as a result of designs based on a thorough analysis of the transient waveform distortion phenomena present in actual EHV systems. The performance of the relays was assessed by unique test methods. The developed relay system now in actual use is described.

Pilot wire relay protection system for electrical distribution networks

Abstract: A pilot wire relay protection system for detecting and responding to phase-to-phase, three-phase, phase-to-phase to ground, and ground current faults including relatively low level ground current faults occurring within an electrical power network is disclosed. The pilot wire relay protection system includes current transformers coupled to transmission lines of the electrical power network for developing coupled currents representative of the transmission-line currents. The current transformers are positioned at the ends of a section of the electrical power network for which protection is desired. The coupled currents from the current transformers are inputted to pilot relays having an analog device for producing a composite signal indicative of the condition of the protected section of the network. The pilot wire relay also includes an electronic device to detect if preset fault limits have been exceeded. Upon detecting a condition indicative of a fault within the protected section, the pilot relay transmits an electrical signal to a power circuit breaker which in turn disconnects the protected section of the electrical power network from the remainder of the network.

Energization circuit for a microwave oven

Abstract: An energization circuit for a microwave oven employs a PTC thermistor to eliminate high transient current surges resulting from energization and deenergization of induction elements therein to provide circuit protection both during oven start and operation. The energization circuit comprises first and second parallel circuit portions for energizing a transformer used to energize a magnetron that produces microwave energy, the first circuit portion including a normally open start switch and a current limiting PTC thermistor coupled in series relation and the second circuit portion including a relay operated switch, a relay for operating the relay operated switch, and a relay circuit portion connected to the first circuit portion between the start switch and PTC thermistor for energizing the relay upon closure of the start switch and then through the PTC thermistor upon opening of the start switch. During start-up, power is briefly supplied to the magnetron through the PTC thermistor to reduce high current surge flow to the transformer until the relay operated switch closes and supplies full power to the transformer and thus to the magnetron. The relay first is energized directly through the start switch upon closure of the latter and then by reverse current flow through the PTC thermistor upon closing of the relay operated switch and opening of the start switch.

Interactive Computation System of Distance Relay Setting for a Large Scale EHV Power System

Abstract: In this paper, discussion is carried about an CRT interactive computation system of distance relay setting for back-up protection.

Electronic remote control D.C. power controller and circuit breaker

Abstract: An electronic remote control D.C. power control and overload circuit breaker for the cockpit controlled D.C. power system of an aircraft or the like. Electronic sensing of overcurrent conditions provides better accuracy, stability and reliability and easier adjustment or adaptation to specific applications. These are attained by using a combination of a shunt resistor in the D.C. line feeding a transient suppressing input bridge and an instrumentation amplifier with common mode rejection followed by a trip time delay network, a threshold comparator and logic and relay control circuitry, as well as supply voltage regulation plus secondary regulation of the comparator reference voltage. A remote cockpit unit affords control and indication. Modifications afford bidirectional sensing of the D.C. bus overload as well as different trip time delays for the two polarities of overload currents.

Dump truck with safety circuit

Abstract: An electrical circuit for driving an electrically driven vehicle such as a dump truck is capable of preventing occurrence of accidents caused by an erroneous operation and thereby increasing safety by providing an arrangement such that the vehicle cannot start unless all necessary operations have been completed before starting. For this purpose, a power source of a control box controlling an exciting current for a generator is turned on to generate the exciting current only when all necessary operations have been completed. This is achieved by connecting a plurality of switches corresponding to various operations in series to a power source relay and thereby causing the power source relay to be actuated upon closing of all of these switches. The circuit also enables the motors to be utilized as generators to provide dynamic braking for the truck.

Submersible remote control switch assembly

Abstract: An electrical shock free submersible, remote control switch assembly for controlling the operation of electrically powered apparatus used with swimming pools, spas and the like is disclosed. The switch assembly includes a permanent magnet actuated reed switch mounted in a battery powered, low voltage electrical circuit. The low voltage circuit, in turn, is optically coupled by an opto-isolator to a relay circuit, which is used to open and close the high voltage circuit powering the electrical pumps, lights, blowers, etc. at the pool or spa.

Automatic power supply system

Abstract: An automatic power supply system for an acoustic apparatus having at least a cassette deck box and an audio box connected thereto, the deck box including an automatic power supply circuit and a tape/radio selector switch. A power source +B is supplied to the automatic power supply circuit or a relay control circuit of the audio box through the selector switch. The power source +B is further supplied to an audio amplifier through a relay which is adapted to be energized or deenergized by the relay control circuit.

Model train crossing gate

Abstract: A detector circuit for a model railroad employs two pairs of magnetically-operated relays positioned on either side of a grade crossing along a set of tracks. In addition a single magnetically-operated relay is located at the grade crossing and is given an orientation orthogonal to that of the two pairs of relays. A locomotive of the model railroad is equipped with a first magnet for operating the pairs of relays and at least one car has a second magnet for operating the relay at the grade crossing. A control circuit is connected to the relays such that crossing gates at the grade crossing are lowered, a bell is sounded, and lights are flashed whenever the locomotive magnet passes over the pairs of relays traveling toward the grade crossing. The control circuit also raises the crossing gate and deactivates the bell and flashing lights whenever the car magnet moves over the relay at the grade crossing or the locomotive magnet moves over one of the pairs of relays while traveling away from the grade crossing.

Fast relay turn on circuit with low holding current

Abstract: A drive circuit responsive to an applied electrical signal for generating a voltage to control the actuation of an electromagnetic relay is disclosed. The voltage has a first and a second level for picking-up and holding-in, respectively, the relay. The first voltage level has a peak value which is developed by an internal charging circuit and is additive to the second voltage level supplied by an external source. The first voltage level is higher than required to actuate the relay which enhances the pick-up speed of the relay.