Abstract: An apparatus and method as disclosed for converting an input data character stream into a variable length encoded data stream in a data compression system. The data compression system includes a history array means. The history array means has a plurality of entries and each entry of the history array means is for storing a portion of the input data stream. The method for converting the input data character stream includes the following steps. Performing a search in a history array means for the longest data string which matches the input data string. If the matching data string is found within the history buffer means, the next step includes encoding the longest matching data string found by appending to the encoded data stream a tag indicating the longest matching data string was found and a string substitution code.

Abstract: A surge suppression circuit for use in a high frequency communication network, having a primary line and a ground line, includes a gas tube connected between the primary line and ground line, a bi-directional avalanche diode and one or more ferrite beads connected in series between the primary line and ground line, and a metal oxide varistor connected in series in the primary line.

Abstract: A high tension circuit breaker comprising at least one circuit-breaking chamber and, in parallel with the circuit-breaking chamber, firstly a varistor in series with an interrupter, and secondly a tension-distributing capacitor. The circuit breaker has a linear resistor having a resistance lying in the range range 30 ohms to 300 ohms inserted in series with the varistor. The invention is particularly suitable for reactance circuit breakers.

Abstract: A device for suppressing electromagnetic static and voltage surges induced on radio frequency transmission cables is disclosed. The device comprises a blocking capacitor connected to prevent the conduction of DC currents but to permit the transmission of radio frequency signals. An inductor coil is connected between one side of the capacitor and ground. The inductor coil is of a value that blocks conduction of radio frequency signals but allows static and low frequency DC voltage surges to be conducted to ground. A gas discharge unit is also connected from the same side of the capacitor to ground. The discharge unit is a secondary discharge device that only operates when the transient speed and magnitude of the surge is sufficient to cause a back emf to develop across the inductor coil above a predetermined limit. The gas discharge unit assures that the capacitor is not damaged by the back emf.

Abstract: An integrated circuit is shown in which provision is made for terminating or locking out the operating circuitry when the supply voltage has fallen below a level that can cause anomalous or unreliable operation. Certain selected transistors are provided with saturation sensors which operate to produce a current when the transistors go into collector saturation. When any of the sensors indicates the onset of saturation, clamping circuitry is energized to provide lock out. In addition, a temperature compensated dummy bandgap circuit is included to sense extremely low supply voltages and provide the lockout function under conditions where a reliable saturation indication might not be available.

Abstract: An arcing fault detector is set up to identify arcing faults and to distinguish them from other disturbances in a circuit. A plurality of electrical conditions are monitored and the conditions are tested against predetermined parameters for establishing a series of logical conditions relating to the presence of an arcing fault. A logic circuit combines the logical conditions for deciding on the presence of an arcing fault. An output signal of the logic circuit is used to activate a relay for interrupting the supply of electrical power to the circuit.

Abstract: A protection circuit for use with an electromagnetic interference filter used in conjunction with a three phase power circuit operating at a particular line frequency includes three capacitors which are coupled to the output terminals of the electromagnetic interference filter. The electromagnetic interference filter and the power circuit have a resonant frequency which is substantially equal to the line frequency. The capacitors of the protection circuit have values which are selected to change the resonant frequency of the electromagnetic interference filter and power circuit such that the resonant frequency is not substantially equal to the line frequency. A protection circuit assembly for use with an electromagnetic interference filter includes a base plate, three ceramic capacitors, three heat conducting substrates, and a protective cover which is mounted on the base plate. The capacitors are mounted on the heat conducting substrates, and the substrates are mounted on the base plate.

Abstract: A protective device for portable apparatus supplied from a high-voltage line is disclosed, which includes a connecting line from an electrical supply. The device also includes a protective switch with contact sets located in the supply lines and pre-stressed contact springs which are maintained in a closed position by a hoop-like fusible wire. An electronic firing circuit is disposed on a flat plate, together with the protective switch and the connections to the supply line and to the apparatus. The two-pole outlet of the firing circuit terminates in contact lugs with which the ends of the fusible wire can be connected mechanically and electrically. The circuit plate is, preferably, seated in the housing of a right angle plug, the contact pins of which are cast or pressed into the bottom of the housing and support the circuit plate while, at the same time, their heads constitute the opposite contact for the contact springs of the protective switch.

Abstract: A non-fragmenting surge arrester with a staged pressure relief mechanism includes a liner with outlets formed in the walls thereof, a gas expansion chamber within the liner and a housing having weakened-wall regions adjacent to the outlets in the liner. Ionized gas formed by an internal failure is vented from the expansion chamber through the outlets and, upon generation of sufficient pressure, fractures the housing at the weakened-wall regions. In this manner, the generated gas forms a lower impedance path for the current which is thereby shunted around the failed internal components, preventing the generation of further internal pressure which could cause a catastrophic failure of the arrester.

Abstract: A Hall-effect magnetic sensor arrangement comprising Hall-effect IC, an anti-surge electric source protective circuit electrically connected to the Hall-effect IC, and a substrate for mounting thereon the Hall-effect IC and the protective circuit. The Hall-effect IC as well as the protective circuit mounted on the substrate are in the form of a hybrid IC.

Abstract: A circuit for controlling the orientation of magnetic fields is provided. The circuit has particular application to a flux shunt trip device in a circuit breaker. The flux shunt trip device has a spring-loaded plunger which when released to its extended position causes the circuit breaker to trip. Under normal operating conditions, the plunger is maintained in a retracted position by the force of a permanent magnet. A trip coil is mounted adjacent to the plunger. When the trip coil is energized a magnetic flux is generated opposing the magnetic flux of the permanent magnet. When the opposing flux neutralizes the flux of the permanent magnet the spring-loaded plunger is released to its trip position. A control circuit is provided to aid in maintaining the plunger in its retracted position under high current conditions close to, but below, the trip value.

Abstract: A recloser apparatus is provided with an enclosure or tank (40) in which a current interrupter assembly (49) is disposed that includes a pair of relatively movable contacts (50, 54) movable between a closed, current-carrying position and an open, current-interrupting position. An opening assembly (60) is included for opening the contacts to the current-interrupting position and a closing assembly (66), including a high voltage solenoid coil (61) and plunger (116) moves one of the contacts (54) to the closed, current-carrying position. An operating assembly (43) is manually accessible from outside the tank (40) and includes an operating arm (44) which is movable between an upper, intermediate and lower position, and a contact closing circuit for initiating operation of the contact closing assembly (66) when the operating arm (44) is manually moved to the upper position.

Abstract: A system for preventing voltage drops when a load circuit is connected and preventing arcing when a load is disconnected from an energized bus includes a current limit device and low impedance shunt that bypasses the current limit device when activated. The system activates the low impedance shunt only after a load capacitance is charged when the load is connected and deactivates the low impedance shunt prior to disconnecting the load.

Abstract: The optional functions of a microprocessor-based trip device are selected by means of keys of a keypad. the different options are displayed sequentially on a display during running of a selection subroutine contained in a read-only memory (ROM), the keypad enabling the selected option to be stored in an EEPROM memory.

Abstract: An electrical recloser apparatus includes a tank (10) having bottom, top and side walls (18, 22, 16) which define an interior, sealed space (14), and a current interrupter (44) disposed within the sealed space (14) and including a pair of relatively movable contacts (46, 48) which are movable between a closed, current-carrying position and an open, current-interrupting position. A control assembly (30) is provided for electronically controlling the opening and closing of the contacts (46, 48), the control assembly (30) initiating operation of the contact moving means (58) to move the contacts (46, 48) to the open position in response to a fault current sensed by a sensing means (66), and initiating operation of the contact moving means (58) to move the contacts (46, 48) to the closed position after each one of a predetermined number of opening operations.

Abstract: A surge preventing circuit for an electromagnetic induction cooker comprising a heating plate temperature sensor, an upper plate temperature sensor, a collector voltage limiting circuit, an abnormal condition sensor, a gate circuit, a minimum turn-on time setting unit, and a minimum turn-on time output controller.The surge preventing operation is carried out by applying a detection signal to a microcomputer when the temperature of the heating plate and the upper plate rises excessively or when the collector voltage of the power transistor is greater than a rated value and cutting off an output voltage of an integrator to be applied to a charge/discharge unit, an then when the output voltage of the charge/discharge unit is lower than a rated value, cutting off the driving of an inverter circuit, thereby preventing a large surge voltage from generating at the inverter circuit.

Abstract: A connector is disclosed which includes a plurality of leads and a conductive plate. The plate includes a number of bores extending through it. The leads are spaced apart the walls of the bores. A quantum mechanical tunneling material is placed between the leads and the walls of the bores in order to support the leads. This configuration serves to connect the leads to the plate by quantum mechanical tunneling when the voltage between the leads and the plate exceeds a predetermined voltage.

Abstract: A circuit is provided which responds to single or multiphase low or lost voltage situations and in the case of multiphase systems to phase reversals or shifts to disconnect a single or multiphase load from its source. A timing circuit is provided which prevents reactivation of the load until a prescribed time interval has elapsed. The reactivation may be either automatic or manual.

Abstract: The sectionalizer control provides a restraint signal responsive to a harmonic current which exceeds a threshold current for less than a preset time.

Abstract: The switch has a gas discharge chamber, in which two electrodes, namely a cathode (11) and an anode (12), are contained, which are spaced a distance (d) apart and are separted from each order by an electrically insulating wall (9a) made of ceramic material or of glass. The cathode (11) is formed with a hole (5). The electrodes (11, 12) are joined to the insulating wall (9a) by a tight metal-ceramic joint or fused joint. The gas discharge chamber is filled with an ionizable low-pressure gas under such a pressure p that the product p.times.d has such a value that a gas discharge between the electrodes (11, 12) will be fired in response to a voltage applied thereof which is disposed in that branch of the firing voltage-pressure characteristic in which the firing voltage descreases as the pressure rises.