Abstract: A switching regulator power supply has multiple regulated and isolated voltage outputs. This is accomplished without the use of separate voltage regulators for each output voltage or extra transformer windings in the input circuitry of the power supply. Instead of an inductor, the primary winding of a transformer is used as the inductive component required in switching type regulators and is connected in series with the first output voltage. The secondary winding provides an isolated second output voltage. The primary to secondary turns ratio of the transformer determines the magnitude of the voltage.

Abstract: A device for connecting standard plastic covered fiber optic cable and armored fiber optic cable to a housing for electrical or electronic equipment. The device consist of a portion of the housing having a passage between an exterior surface of the housing and a interior surface of the housing. At the interior end of the passage is an aperture sized to receive a standard plastic covered fiber optic cable. The passage is tapered such that the interior end has a smaller diameter than the exterior end and the passage is threaded. A bushing is received in the passage. The bushing has a passage through its center through which the fiber optic cable passes. One end of the bushing is threaded and has an aperture in the center thereof sized for receiving a standard plastic covered fiber optic cable. The threaded end of the bushing also includes a longitudinal slot.

Abstract: An AC power amplifier (50) with a pair of push-pull transistors (Q1, Q2) driving opposite sides (36, 38) of the primary winding of an output transformer (T1) controlled by a pair of variable duty cycle, pulse width modulated width trains (A, B) generated on the output of a pulse width modulator (26) controlled, in turn, through means of a wave shaping feedback system to cause the AC output at the secondary winding (20) to track the output of a precision reference sine wave oscillator (12) and through means of another feedback system for automatic DC compensation including a pair of CMOS analog switches respectively driven by the two pulse width modulated pulse trains (A on 28, B on 30) to produce a pair of feedback signals.

Abstract: A photoelectrical sensor (10) provided with a multistaged, filtered amplifier circuit (16) for amplifying voltage pulses from a phototransducer (12) and a filtering I/V converter (14) includes three voltage amplifier stages (28, 30, 32) and three respectively associated band pass filters (34, 36 and 38) for cascade connecting the amplifier stages (28, 30, 32) between the phototransducer (12) and the detector circuit (18) and accumulating attenuation of response to signals at a frequency equal to the frequency of full wave rectified AC line voltage to maximize desensitization of the photoelectrical sensor (10) to AC powered ambient light fluctuations while broadening the pass band at the low frequency end for maximum response to the desired signal. A gain control circuit (40) is associated with the first stage amplifier (28), while a temperature compensation circuit (42) adjusts the gain of a second stage amplifier stage (30) to correct for temperature variations.

Abstract: A wire protection device and system that can operate in combination with non-metallic and metallic enclosures to help prevent damage to branch wiring during drywall installation. In some instances, the device serves to prevent the branch wires from being dislodged from the enclosure. The wire protection device may also be made to fit into a wire clamping system that is molded integrally with non-metallic enclosure.

Abstract: A circuit breaker (51) includes an arc stack of metal plates (52), each of which is disposed parallel to the movement of the contact arm (12), whereby lug strikes which may pass through the vent holes (32) in the housing (16) to the lug (18) are avoided. The arrangement of the metal plates (52) provides protection from such unintended lug strikes without requiring the use of additional parts (e.g., barriers, insulators, and deflectors). A contact arm (12) is provided that is light in mass, but which is still strong enough to resist bending caused by the contact blow off loop forces which occur during fault conditions. Contact arms (12) which have I-beam construction, as well as hollow cylindrical and hollow polygonal construction are capable of carrying currents found in intermediate range circuit breakers; however, they are lighter in mass than solid contact arms and thereby enable faster contact separation and reduced arcing currents.

Abstract: An electric current responsive actuator has a thermally responsive force generator and an electromagnetically responsive force generator. The force generators are coupled together to produce a resultant force on a movable trip actuator. In the preferred specific embodiment of the invention, a shape-memory alloy element serves as the thermally responsive force generator.

Abstract: A dual SIP package for encapsulating a plurality of semiconductor die includes a first group of elongated metal leads each having first and second end portions, and a first group of enlarged metal pads each attached to the first end portion of one of the leads of the first group, a second group of elongated metal leads each having first and second end portions, and a second group of enlarged metal pads each attached to the first end portion of one of the leads of the second group, each of the pads of the first group being parallel to and aligned with a corresponding pad of the second group to form a pair. The first end portion of each of the leads of the first group is parallel to and aligned with the first end portion of a lead of the second group. Each of the die is disposed between and connected to a pair of the pads. The bottom electrode of each die is attached to a pad of the first group, and the top electrode of each die is attached to a pad of the second group.

Abstract: An improved low-cost circuit breaker mechanism is provided which dispenses with the complicated and costly conventional use of latch mechanisms for realizing the tripping action. The circuit breaker mechanism essentially comprises an input electrical terminal having an associated contact where current is received, an output electrical terminal where current is delivered out of the breaker, and a conductive deformable section cantilever blade formed of thermostat metal and adapted to establish a conductive current path between the input contact and the output terminal. The cantilever blade is disposed in a normally closed position with a first end affixed to the output terminal and a second free end contacting the input contact, and is adapted to deflect from its normal closed position to an open position for interrupting current flow when the temperature of the cantilever blade increases as a result of the monitored current exceeding a threshold value.

Abstract: A method of manufacturing a circuit breaker comprises the steps of preassembling the movable parts of the circuit breaker between a pair of frame members and providing a housing that is configured for supporting the unitary breaker assembly without attachments. Other circuit breaker components, attached to the unitary breaker assembly, are also supported in the housing without attachments. A cover is secured to the housing to complete the circuit breaker. Another version of the invention preassembles the movable parts of the circuit breaker and the stationary contact mechanism and trip coil, with the line and load terminals attached, between a pair of supporting frame members to form an operable circuit breaker module. The module is in turn supported in a housing without attachments. The circuit breaker module may be tested and adjusted prior to final assembly.

Abstract: A housing for enclosing a power supply circuit board assembly of the type used in programmable logic controllers is disclosed. Through the use of an adapter plate, the housing can accommodate a wide variety of power supply circuit boards that have multiple input and output components that must be accessible to the outside of the housing. Incoming power is supplied through a terminal block on the front of the housing and output power is presented to an edge connector for supplying control voltages directly to the backplane of a programmable logic controller. A hinged side wall provides easy access to the power supply circuit board and the components on it and slots on the top and bottom of the housing provide venting for cooling the components.

Abstract: A racking mechanism for a fused circuit breaker includes a drive assembly that is removable as a unit from the breaker and fuse truck. A modular assembly includes a drive unit having a drive shaft and a travelling nut and yoke for rotating a pair of levering arms for moving the breaker among a plurality of positions in a cubicle. All interlocks are included on the modular drive assembly. An indicator is cam operated by the travelling nut and includes a face having indicia that identifies the direction of rotation of the drive shaft.

Abstract: An equipment protection device for a multi pole circuit breaker includes a trip coil, having a plunger with a tang, in an adapter housing that is attached to the breaker housing for tripping the breaker load contacts by means of the tang. The tang extends through an aperture in the side of the breaker. The trip coil is controlled by a toroid that is in a remote housing, displaced from the breaker housing and which includes a sensing winding on the magnetic core of the toroid. A ground fault carrying conductor is passed through the toroid window and connects the neutral of the breaker panel to an earth ground. A test button on the adapter housing completes a circuit for supplying current to a test winding on the toroid to simulate a ground fault condition. The trip coil has two independent windings that are individually connected to the load contacts of the breaker such that either winding can operate the trip coil.

Abstract: A scanning infrared sensor (10) in which the scanner (21), detector (32) and temperature converter (35) are all contained in proximity with one another in a single housing assembly (18) enables correction of both emissivity based on emissivity settings (41) for each of a plurality of spot targets (16') along a scan line (16) and correction for DC offset errors based on reference temperature measurement (45) of hot and cold references (34, 36). Correction is performed before digital conversion by an A/D converter (56) by a nulling circuit (46), a programmable gain circuit (50) and a bias circuit (62) to produce corrected digital temperature signals on a plurality of output ports (26) respectively associated to a plurality of spot targets (16') along a scan line (16) on a target (12) which are individually connectable with a multiple temperature display (27), a temperature recorder (28) and a process control (30).

Abstract: The invention provides an oscillatory suppression circuit (54) for use in a photosensor loop circuit (10) employing a phototransistor (14). The oscillation suppression circuit (54) prevents oscillation in the photosensor loop circuit (10) caused by detected unmodulated high frequency light. The oscillatory suppression circuit (54) includes a resistor (58) and a capacitor (62) connected in series, and also connected in parallel with a base resistor (38) of a feedback transistor (26). The oscillatory suppression circuit (54) adds a small amount of phase advance to a feedback circuit (50). This small phase advance counteracts any additional negative phase shift produced when intense light pluses are detected by the phototransistor (14) and amplified by the high gain of the feedback circuit (50).

Abstract: A terminal block adapted for mounting on various domestic and standardized European DIN mounting rails. The terminal block incorporates a number of integral, fixed and flexible retaining members. Each retaining member has one or more slots which, in the proper combination, engage various mounting rails for attachment of the terminal block.

Abstract: A residual current circuit breaker 1 has a partition wall 3 which separates an over-current protection device 4 from a residual current detection circuit 5. A plunger rod 24 extends through a bore 23 in the armature 21 of a coil 20 and is moved independently through the coil 20 to trip the breaker if a residual current is detected by the circuit 5. The plunger rod 24 is moved by a drive rod 31, the operation of which is controlled by a permanent magnet which retains the drive rod 31 retracted and an electromagnet which allows the drive rod 31 to drive forwardly under the action of a spring 32 in the event of a residual current being detected. The plunger rod 30 is reset by a reset lever 40 which is moved when an operating handle 18 of the breaker moves from a non-tripped to a tripped position upon tripping of the breaker.

Abstract: A fault-powered, processor-based circuit breaker tripping system employs a reliable low power trip indicator circuit that is normally powered from the tripping system. A liquid crystal display is used to indicate the status of the system, and a battery is used as a secondary power source after a trip terminates the power to the system. The battery is enabled by a manual switch or by a latch which responds to one of a plurality of trip signals from the processor. The latch also provides signals to a driver circuit to drive the LCD. Once enabled, the battery provides power to the latch and the LCD so that the cause of the trip may be displayed during a power fault. The manual switch can be used to select status signals to be displayed on the LCD, and to indicate the condition of the battery. The LCD includes a segment for indicating that the system is energized and power is being drawn from the current path but that amount of power is below all fault levels and insufficient to operate the system.

Abstract: The invention is a direct current bus voltage regulator for an alternating current inverter, where draws direct current from a DC bus, and the inverter supplies alternating current having a controlled frequency to an AC motor. The alternating current frequency controlled by a signal received through a precedence determining circuit that determines which signal will control the AC current frequency. This circuit receives signals from a ramp generator, an AC current limiting circuit and a DC bus voltage sensing circuit. The precedence determining circuit passes the signal with the highest priority on to a voltage control oscillator which in turn controls the AC current frequency delivered to the AC motor, thereby controlling the motor speed. The ramp generator signal indicates an operator input motor control command and has the lowest priority of the three signals.