Abstract: An overload protector for a telecommunications system with an overcurrent protection device for each signal line in a chamber formed between a housing and a base and in which the base carries the line and ground pins and also an overvoltage device for each pair of the signal pins, the overvoltage device disposed at the base. In one construction, each overvoltage device comprises a solid state semi-voltage surge protection device at the base and a ground conductor extends laterally of the base between the ground pin and the device.

Abstract: A current-limiting load cutout includes at least one contact pair (1, 2) with one contact (3, 5) rigidly linked to electrodynamic current limiter (9, 10) that is electrically connected to controllable pulse current supply (17), and at least one emergency state sensor (12, 13, 14) kinematically linked to contact displacement and clamping assembly (11) which is kinematically linked to the other contact (4, 6) of contact pair (1, 2). The current-limiting load cutout is equipped with a pair of power terminals (20, 21, 22, 23) per each contact pair (1, 2) with one power terminal connected to the other contact (4, 6) of the contact pair (1, 2) and the other power terminal connected to contact (3, 5) which is rigidly linked to electrodynamic current limiter (9, 10) equipped with terminal (15, 16) to which a controllable pulse current supply (17) is connected via an emergency state sensor (12).

Abstract: A fault-powered, processor-based tripping system includes a solenoid for interrupting a current path in response to a trip signal generated by a processor. The processor analyzes current provided by a current sensor, by way of an interface circuit, to determine when the trip signal should be generated. A power supply provides a reference signal to the processor to indicate the amount of power it is capable of delivering to the solenoid. Before attempting to engage the solenoid, the processor checks the level of the reference signal to determine whether or not the power supply is at that time capable of supplying the solenoid with a sufficient amount of power to effect interruption of the current path thereby avoiding a power loss by inappropriate engagement of the solenoid. If the power level is sufficient to engage the solenoid, the processor generates the trip signal to interrupt the current path.

Abstract: A surge absorber utilizes a varistor electrically connected to a surge absorbing element. The varistor voltage and nonlinearity factor are chosen so that the varistor has a preselected voltage-current characteristic which prevents the varistor from breaking down and short circuiting and resulting in a thermal runaway.

Abstract: A proximity switch assembly (10) for signaling the location of a movable member (36) at either of opposite end limits of movement relative to a stationary frame (44, 46) includes a compact elongate housing (58) adapted to be mounted on the frame to extend along the path of movement of a power driven member (32), such as the piston rod of a hydraulic cylinder, which shifts the movable member between its end limits. The proximity switch is fixedly mounted in the housing and carries a switch actuating member (68) mounted for sliding movement over a relatively short distance sufficient to move an actuating target (74) into and out of actuating proximity of an air core proximity sensing coil (120) within the housing. Lost motion abutment shoulders (70, 72) on the switch actuation member and power driven member (54) move into engagement with each other as a power driven member approaches each end of its stroke.

Abstract: A terminal connector or plug protector is selectively configurable for coupling or coupling and protecting an electronic communication circuit to a communication line. The plug protector has a housing and a circuit board which is received in the housing. The circuit board has thereon a circuit which includes a plurality of circuit elements removably received in the circuit board. The circuit is coupled to the communication circuit and to the communication line with the circuit elements coupled therebetween. The circuit elements are selected from among a plurality of circuit element types, i.e., jumper wires, solid state voltage suppressors, and fuses, to configure the plug protector for the selected coupling or coupling and protecting.

Abstract: Surge suppression is provided by varistors connected between, respectively, hot and neutral conductors and hot and ground conductors, each through a common fuse that avoids hazardous overvoltages on the varistors. A first indicator circuit portion provides an indication that the power is on and surge protection is present and includes a first indicator device such as a green light-emitting diode that is energized when the fuse is intact, and a second indicator circuit portion is provided for indicating power is on and surge protection is lacking that includes a second indicator device such as a red light-emitting diode that is energized by the line conductors when the fuse has been interrupted. The surge suppressor and dual indicator apparatus can be contained within a wiring device such as a receptacle. A single varistor unit containing two varistor disks with three leads, including a center tap, allows three effective surge suppressor circuit branches in a compact configuration.

Abstract: A fault indicator which senses current in a cable, resets in response to a minimum current and arms a trip arrangement in response to current rising a predetermined amount with respect to time. If the rising current also opens a circuit breaker within a predetermined time and cuts off current to the cable, the indicator trips. If no zero current occurs within the time period, the trip arrangement is disarmed for the next current rise.

Abstract: A load cell includes a load sensing section which is formed by a rigid load introduction section, a rigid load support section and a strain sensing section, and a base plate having a neck and two parallel plate-shaped rigid sections. One part of the plate-shaped rigid section of the base plate is integratedly fixed to the load sensing section, and the strain gauges are mounted on the strain sensing section formed on the load sensing section so as to detect a load applied to the load introduction section and convert the magnitude of a measured load into a quantity of electricity.

Abstract: An electronic flash charging circuit for use with a camera having a power source common to a microcomputer that controls a plurality of camera functions and to an electronic flash. The charging circuit has a booster circuit for boosting a charging voltage with which a main capacitor of the electronic flash is charged and a controller that causes the booster circuit to operate intermittently, thereby intermittently charging the main capacitor.

Abstract: A safety device for a vehicle occupant comprising a restraint for the vehicle occupant, a sensing circuit for evaluating a vehicle condition, a control circuit for actuating the restraint in response to a predetermined vehicle condition, and two separate reserve energy storages for supplying electrical energy to the sensing and control circuits, respectively.

Abstract: A temperature switching device for an electrotechnical part to be protected against an excess temperature due to a fault, with a first bimetallic switch and an ohmic resistor connected in parallel thereto, so that, after opening the bimetallic switch as a result of an excess temperature, the flow of current takes place across the ohmic resistor, which produces heat and as a result the bimetallic switch is kept open even in the case of the cooling of the excess temperature initially triggering the switching process due to a malfunction of the electrotechnical part to be protected, as a result of the evolution of heat of the ohmic resistor. At least the ohmic resistor is connected in series with a further automatically resettable thermal switch having an opening temperature above that of the first thermal switch, but well below temperatures causing irreversible damage to bimetallic elements and the two thermal switches being in close thermal contact.

Abstract: A multiple element current sharing surge voltage protector is connected in parallel between a voltage source and the input of an electrical load. The protective network includes a low pass shunt capacitor filter, a first suppressor having a selenium varistor clamping device connected in parallel shunt relation with the low pass capacitor filter, and a second suppressor having a plurality of MOV varistor clamping devices connected in parallel shunt relation with the low pass capacitor filter and the selenium suppressor. The parallel connected MOV varistors remain substantially in a non-conducting, open circuit condition until the surge voltage exceeds the turn-on clamping voltage of the MOV suppressors. After turn-on of the MOV varistors, the total surge current flow is divided through the selenium varistor and the multiple MOV varistors, and the shunt capacitor.

Abstract: A device for protecting delay-line modulators of this type by detecting turn-off of the discharge thyristor by a comparator so as to prevent closing of the charge thyristor as long as the discharge thyristor is in the conducting state. This has the effect of preventing short-circuiting of the feed source.

Abstract: A meter base surge suppression system is mountable on a meter mounting panel and is adapted to receive and hold a conventional electric meter. The surge suppression system includes a base plate having a plurality of openings through which contact prongs may be inserted, and an electrical contact element disposed about one of the openings for making electrical contact with a prong inserted through the opening. A surge suppression device is disposed on an upper side of the base plate and is coupled between the contact element and ground potential. A receiving plate is mountable on the base plate and is adapted to receive and hold a conventional electric meter. The receiving plate includes a plurality of buss elements which extend downwardly through the receiving plate and through the openings in the base plate to engage and be received into prong receptacles of a meter mounting panel on which the urge suppression system is mounted.

Abstract: There is disclosed a superconducting switch including two superconducting coils wound on a common bobbin wherein these coils have the same critical current value, and are connected in parallel so that magnetomotive forces which are the same in magnitude and opposite to each other in direction are produced. This superconducting switch is non-inductive and responds to an overcurrent to securely operated at a high speed. There is also disclosed a current limiter including a current limiting coil connected in parallel with the superconducting switch used as a trigger coil. The superconducting switch exists within a magnetic field produced by the current limiting coil. There is further disclosed a current limiter such that the current limiting coil is constructed to be of non-inductive type using two coils, and a superconducting switch is connected to either of these coils.

Abstract: A tingle voltage filter, comprising a saturating reactor connected between the neutral and the local bonding to ground of an electrical service so as to reduce ground currents, is associated with a device to determine whether the potential, referred to a remote ground, at the bonding significantly exceeds that at the neutral, also referred to a remote ground, thus indicating a wiring fault which may make desirable removal of the impedance of the filter from the local connection between the neutral and the bonding. Upon detecting such a condition, the device closes a switch to bypass the filter. The device also contains indicators of elevated potential of the local ground bonding relative to the remote ground, and elevated potential of the neutral relative to the remote ground, to provide further indications of abnormal conditions and of proper operation of the filter.

Abstract: An apparatus for flicker protection when a servo motor driven sewing machine starts utilizing comparators. Setting the original voltage as the reference voltage and the dropped voltage as the monitor voltage, the comparator compares the voltages and, if the difference exceeded more than the predetermined value, signals for setting the maximum electric current to the servo motor are attenuated such that the voltage drop of the electric source will be reduced.

Abstract: An apparatus for monitoring phased currents in a first winding and a second winding of a transformer and for disconnecting the transformer from a power source supplying the transformer when a difference between the magnitude of the current in the first winding and the magnitude of the current in the second winding exceeds a predetermined amount to indicate a fault condition is disclosed. The apparatus is used in combination with circuitry for generating first and second current signals each having a phase and magnitude which is a function of the phase and magnitude of the phased currents in the first and second windings, respectively.

Abstract: The diagnostic circuit comprises a comparator having a first input connected to the power device and a second input connected to a reference voltage generator. A signal generator is connected to the output of comparator so as to generate a diagnostic signal when comparator detects a current in the power device which is higher than a preset value corresponding to said reference voltage. A thermal protection unit sensitive to the temperature of the power device acts on the reference voltage generator so as to reduce the value of said reference voltage in response to an increase in the temperature beyond a preset limit.