Abstract: A method and circuit for determining and extinguishing electrical faults includes a power supply, and electrical load, a controller module, and electrical sensors, and when the controller module does not extinguish the electrical fault, another switch blows a fuse.

Abstract: A relay for closing or interrupting the electric circuit between two relay connection contacts includes two contact springs which are each fixed in an electrically conductive manner to the relay connection contacts with the spring ends thereof facing away from each other and which face each other with the other free, deflectable spring ends thereof. A stationary, electrically conductive contact bridge, against which the free spring ends abut in the closed relay position and from which the free spring ends are lifted in the open relay position, is included. A single solenoid-operated mechanism is for the synchronous, parallel deflection of the two contact springs into the closed or open relay position.

Abstract: A voltage switchgear assembly is disclosed, which includes a short-circuiting unit having short-circuiting devices arranged as a three-phase unit. A support is configured to receive the short-circuiting unit and is configured to be inserted into and withdrawn from an openable section of a switchgear assembly housing.

Abstract: Methods and techniques to implement a digital signal processor for avoidance of audio feedback are disclosed, in particular, audio signal processing systems that reduce the requirement for physical segregation of sound acquisition and diffusion zones. In a more general aspect, the components and techniques described herein provide a for a sound space and sound processing equipment such that sound travelling electronically in a loop through the sound processing equipment that is output into a physical sound diffusion zone, received at the input to the sound processing equipment, and then re-amplified, etc. is attenuated over that loop by frequency modification. The frequency modification is such that, at least for some signals, on each pass through the loop, the sound processing equipment will attenuate or amplify individual sub-bands of the frequency spectrum of the audio signal that is received at the input of the sound processing equipment.

Abstract: An input circuit includes an interface structured to output a logic signal from an alternating current signal of a pair of elongated conductors. A load is switchable to the elongated conductors. A processor outputs a control signal to switch the load to the elongated conductors asynchronously with respect to the alternating current signal for a first predetermined time, inputs the logic signal, determines if the input logic signal is active a plurality of times during the first predetermined time and responsively sets a first state of the alternating current signal, and, otherwise, sets an opposite second state of the alternating current signal, and delays for a second predetermined time, which is longer than the first predetermined time, for the opposite second state before repeating the output, and, otherwise, delays for a third predetermined time, which is longer than the second predetermined time, for the first state before repeating the output.

Abstract: A self diagnostic solid state relay for converting a low current input into a high current output and providing the combined functions of silent switching and visual indication of circuit status. A three dimensional polygonal shaped housing encloses a printed circuit board. A MOSFET field effect transistor, a pair of female circuit board terminals, and a pair of LED elements are electrically communicable with a first side of the printed circuit board, the LED elements further being viewable from an exterior location of the housing. A fuse including first and second spaced apart and extending blade portions engage, respectively, with the first and second female terminals through openings defined in the housing. A plurality of male circuit board terminals are in electrical communication with a second side of said printed circuit board and extend from further selected exterior locations of the housing.

Abstract: A method of analyzing an electromagnetic interference amount of an LSI includes an equivalent impedance information calculating step of calculating and estimating equivalent impedance information based on circuit information of an LSI chip and package information of the LSI chip, and an electromagnetic interference noise calculating step of calculating an electromagnetic interference noise based on the equivalent impedance information.

Abstract: An H-type motor bridge coil driver circuit is implemented with an electronic switch in each leg segment of an H-shaped circuit, this bridge circuit having its side legs each connected between a power supply and ground, with the inductive load of a motor coil being connectable as the cross leg of the H-shaped circuit. An alternate current path, voltage level stabilizing element may be connected across each leg segment electronic switch. A coil excess energy storage element may be connected to the coil nodes of the circuit, through alternate current path elements and utilized to temporarily store the discharging of the excess coil energy normally available because of the lagging nature of the motor coil current. This temporary storage element then may discharge this energy back to the power supply through a passive circuit element, and reverse polarity protection is included for the power supply.

Abstract: The high transient current sustained by arcing during opening of the main contacts of a miniature circuit breaker is commutated out of the bimetal by deflection of the bimetal in response to the overcurrent to close secondary contacts on the free end of the bimetal and on a low resistance by-pass conductor shunting the bimetal. The by-pass conductor can be extended toward the movable contact arm carrying the movable main contact to commutate some of the overcurrent into the by-pass conductor earlier in the opening sequence to reduce the energy input to the bimetal and reduce the force closing the secondary contacts.

Abstract: A combined ground fault and arc fault circuit interrupter includes a differential current transformer, a hot electrical line and a neutral electrical line passing through the current transformer and forming the primary thereof, an asymmetrical current transformer having a core through which the hot and common electrical leads pass, and a secondary wound on the core for producing a signal more strongly responsive to the current in the common line than in the hot line. An arc fault detector is connected to the secondary of the second transformer, while a ground fault detector is connected to the secondary of the first transformer, and the outputs of the ground fault and arc fault detectors are both connected to a circuit interrupter arranged for disconnecting the circuit when either a ground fault or an arc fault is detected.

Abstract: A circuit protection apparatus includes a circuit breaker coupled in series with a circuit to be protected. The circuit breaker has a trip input and is responsive to a trip signal at the trip input for changing from a closed circuit condition to an open circuit condition to thereby remove electrical current from the circuit to be protected. A thermal trip element is coupled in series with the circuit to be protected and is responsive to a predetermined current/time characteristic of current flow in the circuit for delivering the trip signal through the thermal trip element to the trip input.

Abstract: An overcurrent trip device includes a capacitor 13 that stores power for driving a trip electromagnet 7, and a charging current generating means 18 that starts charging the capacitor 13 upon detection of an overcurrent and that completes the charging of the capacitor 13 until a trip control circuit 5 outputs a trip signal. The operation of the trip electromagnet 7, which is driven with the charges of the capacitor 13 by causing a thyristor 12 to be turned on by the trip signal, is continued until the charges of the capacitor 13 are lost, and even after the power supply from a rectifying circuit 4 is stopped due to the opening of a circuit breaker 8, it is made impossible to reset and re-close the circuit breaker 8 for a predetermined time.

Abstract: A residual current safety switch has a residual current transformer (3) connected to an evaluation circuit (5) that controls an electromagnetic trigger device (K1) for actuating switching contacts (1, 2). An overvoltage protection circuit (V1), for example designed as a voltage-dependent resistor, is provided. The evaluation circuit (5) and/or the overvoltage protection circuit (V1) are/is connected to terminals that supply them with voltage when the switching contacts (1, 2) are closed through lines (7, 8), with one of the lines extending through the residual current transformer (3) and the other not. The supply current of the electronic components and/or the current that flows through the overvoltage protection circuit (V1) is lower than the triggering current when the nominal voltage is applied.

Abstract: A circuit interrupter provides a conducting path between two conductors and interrupts the conducting path in response to overcurrent conditions in the conductors. The interrupter includes a magnetic core around which the conductors are disposed. Each conductor is electrically coupled to an arc runner and a spanner is biased into contact with the arc runners to compete a conducting path between the conductors. A secondary response mechanism is provided adjacent to the core and includes arms extending around the core and a magnetic body. In response to overcurrent conditions of a first magnitude the body of the secondary response mechanism is attracted to the core causing the arms to displace the spanner out of contact with the arc runners. In response to overcurrent conditions of a second magnitude, such as due to direct short circuits, the spanner is repelled rapidly to a non-conducting position and the secondary response mechanism is attracted to the core to hold the spanner in the non-conducting position.

Abstract: A circuit breaker/surge arrestor package for plug-in installation in the space of two standard one-inch openings in a contemporary residential load center. The electrical and thermal characteristics of the components are selected such that a threshold of a substantially continuous current through a Metal Oxide Varistor in the surge arrestor causes the circuit breaker to trip magnetically before being able to trip thermally.

Abstract: In this power control apparatus, a current flowing in a main current (201) is detected by a current transformer (202) and a zero-phase current transformer (203), provided in the main circuit. A value of this current is provided to a CPU (214) included in an intelligent controller (207). A maximum peak value and the like are evaluated by the CPU to be compared with predetermined set values. If those values are equal to or higher than the set values, an excitation signal is applied to a tripping device (205) to release a latch by a latch scheme (206) and thus to trip the circuit breaker. The CPU alters the set value when supplied with a setting alteration instruction from a central monitor (40), and causes the circuit breaker to be tripped when supplied with a stop instruction therefrom.

Abstract: An apparatus for protecting the fault current intolerant elements of a motor starter circuit or the like is comprised of a protective shunt which bypasses the fault current intolerant elements in response to the detection of high fault currents. The protective shunt is formed of a "U" shaped conductor which flexes in response to the magnetic field created by the flow of the high fault currents through the "U" shaped conductor. Electrical contacts place on one leg of the "U" shaped conductor and on a stationary conductor form a shunting switch which conducts high fault currents around the starter circuitry. In a second embodiment, the stationary conductor is replaced with a flexible conductor which carries an armature. The magnetic armature is attracted by a focussed magnetic field from a magnetic yoke positioned around one leg of the "U" shaped conductor.

Abstract: A wound bobbin coil (A) and a fuse (B) are interconnected electrically in series. The coil and the fuse are mounted closely adjacent and molded into a tough, nylon encapsulation (C). The series connected coil and fuse are connected with electrical terminals (26, 30) to form a unitary electrical component which is readily connected with associated circuitry. In this manner, when the coil becomes damaged sufficiently to blow the fuse, both the coil and the fuse must be replaced. A repairman cannot short the fuse or merely replace the fuse and allow a damaged coil to continue functioning. In the preferred utilization of the present coil in a freezer compartment ice maker, coil failures can cause flooding, overheating, and other catastrophic damage to a refrigerator/freezer.

Abstract: A changeover contact-making apparatus with interlocking member and module of protection protected against overcurrents is provided. In a same case, two contact-making systems and coil switches are disposed on each side of a median plane PP' in which the interlocking member is placed. In one of the case inner volumes defined by the plane PP' are placed a single protection module, a tripping mechanism and the respective connection terminals.

Abstract: A wound bobbin coil (A) and a fuse (B) are interconnected electrically in series. The coil and the fuse are mounted closely adjacent and molded into a tough, nylon encapsulation (C). The series connected coil and fuse are connected with electrical terminals (26, 30) to form a unitary electrical component which is readily connected with associated circuitry. In this manner, when the coil becomes damaged sufficiently to blow the fuse, both the coil and the fuse must be replaced. A repairman cannot short the fuse or merely replace the fuse and allows a damaged coil to continue functioning. In the preferred utilization of the present coil in a freezer compartment ice maker, coil failures can cause flooding, overheating, and other catastrophic damage to a refrigerator/freezer.

Abstract: A modular ground fault circuit breaker is provided by the arrangement of a ground fault module and signal processor module operatively connected with a circuit breaker module. EAch of the modular components are individually tested and calibrated prior to assembly. The circuit breaker module consists of an automated residential circuit breaker modified to receive the ground fault and signal processor modules.

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.

Abstract: A detecting circuit comprises a magnetic core having a rectangular magnetic characteristic, a first winding coupled magnetically to the magnetic core, for applying a current to be detected, and a second winding coupled magnetically to the magnetic core, for applying a reference current. An output signal is derived from the second winding.