Abstract: Stray voltage reduction apparatus for installation in an electrical power system to complete a path of electrical continuity between a primary neutral of a power distribution transformer and a grounding conductor at a service entrance, the primary neutral being also attached to a ground connection but nevertheless having a stray voltage relative to true earth which would appear on the grounding conductor at the service entrance if the primary neutral were directly connected to the grounding conductor at the service entrance. The stray voltage reduction apparatus includes a coil having turns wound around a core establishing a magnetic circuit for the coil. The core is made of a material having an initial permeability in excess of about 50,000 and being substantially saturated when the flux density is no more than about 10,000 gauss. The coil is wound around the core to have an impedance at 60 Hz.

Abstract: A method of converting a mechanically operated punch press to a hydraulically operated punch press, the mechanical punch press being of the type having a motor-driven flywheel coupled with a crank journaled between two bearing seats, the method comprising disconnecting the flywheel, replacing the crank with a hydraulic ram having trunnions projecting laterally therefrom and sized and positioned to be journaled in the same bearing seats in which the crank was journaled, and connecting the hydraulic ram to a source of hydraulic fluid. A controller can be interposed between the source of hydraulic fluid and the ram to control the operation of the punch press.

Abstract: Apparatus and method for reducing the voltage drop in an electrical power distribution system during the starting of a multi-phase induction motor having stator windings supplied therefrom and for decreasing the loss in starting torque of the motor. A capacitor is provided for direct connection across each stator phase winding of the motor. These are electrically connected to the stator windings substantially simultaneously with the motor being supplied with power from the distribution system. These capacitors have a capacitance which exceeds that required to raise the no-load power factor of the motor to unity at running speed but is less than that which will correct the power factor of the motor to unity under locked rotor conditions. Preferably these capacitors are electrolytic-type capacitors and have a capacitance which will reduce the motor starting current by at least approximately 30%.

Abstract: A three-phase delta-wound motor adapted for operation from a source of single-phase current, which motor includes first and second terminals adapted to be connected to the single-phase current source and substantially identical first, second, and third phase windings. A capacitor and the first and second phase windings are series-connected one with the other across the first and second terminals, the polarity of the first winding with respect to the second winding being opposite that of a normal delta-wound motor. The third phase winding is connected directly across the first and second terminals in parallel with the serially-connected capacitor and first and second phase windings.

Abstract: A transfer switch comprising a support, first and second fixed contacts mounted on the support and adapted to be connected to first and second sources of power, respectively, a rocker pivotable between first and second positions, a contactor carried by the rocker. The contactor is movable with respect to the first and second contacts and is engageable with the first fixed contact when the rocker is in its first position and with the second fixed contact when the rocker is in its second position. An actuator is provided for moving the rocker between its first and second positions, whereby the movable contactor is adapted to be connected to a first source of power when the rocker is in its first position and to a second source of power when the rocker is in its second position. The actuator comprises a shaft rotatably mounted on the support and an overcentering spring, the shaft having a handle and a crank and the spring being secured at one end to the crank and at the other end to the rocker.

Abstract: A rotary phase converter for connection to a single-phase a.c. power source and adapted to supply polyphase current to a polyphase electrical load. The converter includes a dynamoelectric machine having at least three stator windings and at least first, second and third output terminals, an autotransformer and at least one capacitor. The stator windings of the dynamoelectric machine are oriented symmetrically with respect to each other both physically and electrically and each has a substantially equal number of active turns. The first and second terminals of the dynamoelectric machine are adapted to be connected to the single-phase a.c. power source and they are also outputs of the converter. The autotransformer is connected across the second and third terminals and has at least one tap positioned intermediate the ends thereof to serve as an output of the converter. The capacitor is connected between the first output terminal and the autotransformer tap serving as a converter output.

Abstract: A rotary dynamoelectric machine having a generally annular polyphase stator with a predetermined number of wound poles and an induction rotor. The rotor has a cylindrical laminated ferromagnetic core positioned within the stator for rotation about a central axis thereof when the stator is energized by an a.c. power source. The rotor is of squirrel-cage construction having a plurality of electrically conductive bars each extending the length of the core adjacent the cylindrical surface thereof. Conductive end rings at the ends of the rotor are electrically connected to the ends of the bars at the respective ends of the core. The end rings have a plurality of radial slots therethrough thereby forming a plurality of spaced arcuate ring segments whereby the rotor has a relatively high resistance, e.g., at least three times that of such a squirrel-cage rotor with unsegmented end rings. The stator windings may be interconnected with a source of single-phase a.c.

Abstract: A self-starting rotary converter for connection to a single-phase a.c. power source and for supplying polyphase current to a polyphase electrical load. A generally annular polyphase stator has a predetermined number of poles and at least three stator windings symmetrically oriented physically and electrically. An induction rotor positioned within the stator rotates about a central axis thereof when the stator is energized by single-phase a.c. power. One of the stator windings has at least one electrical tap positioned intermediate its ends, and a second stator winding has one of its ends connected to the tap to effect electrically nonsymmetrical operation of the stator. This maintains the currents supplied to the phases of the polyphase load at its maximum rating substantially balanced.