Abstract: A weld controller employs a stepper program for increasing heat boost in one percent increments or steps to provide compensation for contact tip wear. The weld controller acquires weld current data in the form of current samples for each step to create a characteristic curve or nominal current profile for the stepper program. Subsequent operations of the weld control utilize high and low current limit thresholds that track the nominal current profile. The thresholds can be defined as a fixed offset from the profile or as a percentage of the profile at each step of the stepper program. This allows the use of current limits to be established in close proximity to the nominal weld current at all times, enabling the use of tighter tolerances.

Abstract: A dry type transformer has an iron core, high voltage windings embedded in cast resin, and low voltage windings resin encapsulated. The iron core is manufactured with stacked core steel. After the core is stacked, instead of using banding straps, a heat shrinkable material is wrapped around the core legs and is heated to enable the shrunken material to apply uniform compression over the core legs. This will facilitate coil loading, reduces audible core noise and reduce core losses. In place of shrink wrappable material, a film material with elastic properties could be used.

Abstract: A high current capacity blade for a circuit breaker, comprises a conductive blade body having front and rear sections connected to one another, where the rear section includes a surface attachment area for fastening a flexible connector of the circuit breaker thereto. A strain relief tang extending from the rear section of the blade body is used to engage the flexible connector so as to stabilize the fastening of the flexible connector to the surface attachment area. A broad conductive lateral section is connected to and extends laterally from the front section, and includes a blade tab for engaging a toggle spring of the circuit breaker. A broad moveable contact is mounted on the broad lateral section and is adapted to interface with a stationary contact of the circuit breaker. A pair of substantially parallel L-shaped blade legs are spaced from one another to permit the toggle spring to pass therebetween.

Abstract: A current mode control apparatus generates an AC power output from a DC input source. The apparatus includes a pulse width modulator (PWM) to produce gate drive signals for driving a power output section having an output inductor and connected across the DC input source. An inner current error control loop coupled between the AC power output and the PWM, controls the average current in the output inductor by generating a current error signal for inputting to the PWM for conversion to the gate drive signals. The current error signal is the difference between the average current and a voltage controlled input signal. An outer voltage error control loop coupled between the AC power output and the inner current error control loop generates a voltage error signal based on the difference between the AC power output and a reference AC voltage.

Abstract: A power output driver circuit that converts a DC voltage into an AC voltage includes a gate driver circuit for turning on electronic switching devices. The gate driver circuit allows for a rapid turn-off of the conducting electronic switching device by having a first conduction path for the gate drive signals that turn-on the switching devices and a second conduction path that rapidly discharges stored energy in the gate/drain capacitance of the switching devices, resulting in a faster turn-off time. A transistor in the gate circuit shunts the stored charge directly to the source terminal of the switching device.

Abstract: A blade suspension assembly for a circuit breaker includes a first electrical contact, an elongated contact arm having a second electrical contact adjacent a first end of the contact arm, a compression spring, and an elongated lever. The second electrical contact is movable about a first pivot axis between a contacts-closed position and at least one contacts-open position with respect to the first electrical contact. The lever has a first end adjacent a second pivot axis, a second end supported by the compression spring, and a contoured support surface between the first and second ends which supports a second end of the contact arm. The compression spring exerts a force against the second end of the lever so that the contoured support surface biases the second end of the contact arm about the first pivot axis in the contacts-closed position during normal operation and in the contacts-open position in response to the contact arm moving to the contacts-open position.

Abstract: A signal distribution and communication arrangement controls the broadcast of different types of signals through speakers located in various zones. The system includes a telephone interfaced with a door speaker controller to allow communication between the telephone and a door speaker. A page may be broadcast over the speakers and subsequently muted to allow private communication when the page is answered. Also included is a doorbell interface circuit that responds to a doorbell source. The doorbell source may be activated by any one of a plurality of doorbell switches.

Abstract: There is provided an enclosure that encapsulates a current transformer by utilizing a snap together design while allowing for electrical coupling between the transformer and external wiring. Two housing members will snap together while capturing the transformer in a rigid fashion to avoid excess vibration or friction, which could fatigue the transformer's wiring.

Abstract: An enclosure for electrical or electronic devices having components requiring periodic adjustment is provided with an access opening to the adjustments for the components including a hinged, attachable door for closing and sealing the access opening.

Abstract: The invention provides a spring exerting a non-linear force between a contact carrier and a contact blade in a circuit interrupter. The inventive spring includes at least one elongated cantilever. The length of the cantilever has the shape of an arch made with a non-uniform angle and is formed from an elastic material. The cantilever is supported at one end against the carrier with the length of the cantilever positioned parallel to the carrier and the opposite end of the cantilever abutting the contact blade so that the carrier supports more of the length of the cantilever as the displacement between the carrier and the contact blade decreases.The invention also includes a method of operating a circuit interrupter by non-uniformly increasing the force exerted against a movable contact as it engages a stationary contact to complete a circuit.

Abstract: An electrical distribution load center consists of a non-conductive enclosure and a circuit breaker bus bar support panel that are interconnected by interlock members that can be snap-fitted to secure the two panels to each other. The support panel also has a latch member so that the bus bars can be mounted onto the panel in a heat-staking, insert-molded or snap-fit arrangement. The support panel also has elements for locking the circuit breakers onto the panels in conducting contact with the bus bars. The enclosure and the support panel are enclosed by a non-metallic trim panel that has a non-metallic door hinged thereto and which carries a latch for latching the door to the trim panel.

Abstract: A machine operator control station circuit which uses capacitive proximity switches to replicate the function of mechanical switches used in prior art control stations. A monitoring circuit for monitoring the "on" state of the capacitive proximity switches used in a two hand industrial machine control station is disclosed. The circuit also reduces the chance of unintended operation of the machine being controlled as a result of emitted or conducted radio frequency interference which might be detected by the capacitive proximity switches. An isolation transformer provides an isolated power supply for the monitoring circuit. The monitoring circuit includes a first capacitive proximity switch for detecting the presence of one of the machine operator's hands, and a second capacitive proximity switch for detecting the presence of the other of the machine operator's hands. Each proximity switch has a monitoring circuit for monitoring the length of time the proximity switch remains in the activated or "on" state.

Abstract: For use in a trip unit, a switched current shunting arrangement in a circuit interruption tripping system couples the current transformers to a relatively low voltage and it accumulates a high level of energy quickly at power-up so that the tripping solenoid can promptly be energized after the detection of a spurious fault condition. The arrangement regulates supply current from the current transformers to a trip voltage capacitor and to a supply capacitor at the input of a voltage regulation circuit. The current transformer charges the trip voltage capacitor to a first prescribed voltage level, and a current shunting circuit shunts current passing from the current transformer to the supply capacitor, such that during normal operation the supply capacitor is charged to a second prescribed voltage level, which is less than the first prescribed voltage level.

Abstract: A semiconductor package houses a plurality of single two terminal semiconductor components. The package is a plastic or ceramic small outline integrated circuit package and is adapted for surface mounting. Each semiconductor element is in a die form and one terminal is directly bonded to one of the external leads. The other terminal is bonded to a jumper that in turn is bonded to the other lead. The resultant package is encapsulated and the external leads are formed for surface mounting. V-shaped grooves formed on the top and bottom of the package separate each semiconductor component and provide a means to separate each or a combination of individual semiconductor components from the package by allowing them to be snapped apart at the V-groove. The resultant package has a very low profile that allows it to be used in thin profile, high density electronic assemblies.

Abstract: A head assembly for a compression tool including a pair of opposite, rotatably mounted jaw members. Each jaw member having a compression end which is moveable between a first position in engagement with the compression end of the opposite jaw member and a second position wherein the compression ends are spaced apart from each other. The compression end of each jaw member having an interior nib surface, a semi-circular groove surface, an engagement surface and distal compression surface. The head assembly includes a center nib which is operably associated with the interior nib surface of each jaw member to provide three generally equidistant points of contact around the circumference of a connector that is placed therebetween for compression.

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 on tripping of the breaker.

Abstract: A speaker support frame structure and optional cover for recessed mounting of a speaker in a wall or the like. The frame structure incorporates a one-piece, unitary molded frame body which has an open central region, a flattened perimeter region adjacent thereto, an adjacent peripheral upstanding shoulder region, and a terminal outwardly turned collar region. A speaker is nestably received thereon. Leg members are associated with a screw that extends through an orifice formed with the frame body. The leg members pivotally outswing and engage wall surfaces with adjustable clamping force. The frame body can be further provided with a frontal first ridge and also with a cover plate which has a rear second ridge so that the first and second ridge can engage mutually in a connecting relationship.

Abstract: The invention provides a mounting frame structure for association with a preformed aperture in a wall and for recessed mounting of a speaker or camera having a housing. The frame structure includes a one-piece, unitary frame body having an open central region for receiving therethrough body portions of the housing. The frame body has a flattened perimeter region and apertures individually located in the perimeter region. The frame structure also includes a shoulder region upstanding rearwardly from and extending substantially about the perimeter region. A mounting flange upstands rearwardly in a perpendicular direction from the perimeter region. The mounting flange has a generally flat shape and at least one aperture therethrough so that the mounting flange abuts and secures to a stud or cross-member of the wall. Optionally, the frame structure is utilized in an assembly with a mounting bracket for the camera or speaker and a cover plate thereover.

Abstract: There is provided a distribution system and a wiring format which will not only provide for a common enclosure, which will help to centralize the entrance of services to a facility, but will also organize the services throughout the facility. In particular, the invention includes an enclosure that will house telephone/audio distribution equipment, video distribution equipment and other systems which are desired by the facility owner.