Abstract: The device provides a power-supply section (3) connected to an AC source (21) and an inverter section (5) for supplying power to an electrical load (9, 11) through an oscillating circuit (13, 15). Two capacitors, a filter and a smoothing capacitor (27, 29) are arranged between a rectifier bridge (25) and the controlled cutouts (33, 35) of the inverter. The power-supply section (3) has an inductor (39) with a value such that the power-supply section (3) exhibits a predominantly inductive behaviour towards the inverter section (5).

Abstract: This invention relates to a dual buck converter used to reduce an unregulated high input voltage without a ground reference to a regulated output voltage. This is accomplished by coupling the inductors of two independent buck converters. The input voltage is split across the dual buck converter and the mid point is balanced by coupling the inductors and switching the two switches at the same time. The inductors are wound on a single core, with the windings magnetically coupled, to form a new coupled inductor.

Abstract: An electronic ballast is used for providing a voltage with a varying frequency to fluorescent lamps. The electronic ballast has an inverter to supply a fluorescent lamp load with a voltage having a high frequency, with the inverter being controlled by a control which generates a switching signal. The ballast further includes a triangular current wave generator which provides a triangular waveform that modulates the frequency of the switching signal controlling the inverter. The modulation of the switching signal causes the frequency of voltage supplied to the fluorescent lamp load to vary from the resonant frequency of the circuit.

Abstract: A mounting assembly secures a generator and facilitates attachment to a railroad railcar on the end of the railcar axle. The generator produces electricity from the axle of a railroad railcar while it is traveling on a railroad track. A generator is mounted with a generator bracket and a backing plate to an existing bearing adapter on the railcar. A drive hub engages axle bolts on the railcar axle. As the railcar axle turns, the drive hub turns and with the drive hub connected to a generator the generator subsequently rotates to supply electricity to the railcar. Different types of generators can be attached with the mounting assembly to the railcar. The mounting assembly allows generators to be mounted without modification to the existing railcar structure.

Abstract: An auxiliary bearing assembly is used to ground the shaft of an electric motor to reduce unwanted currents in the motor bearings. An auxiliary bearing is either initially mounted onto the housing of the motor or retrofitted to attach the motor, so that the shaft of the motor is in electrical and mechanical contact with the center bore of the auxiliary bearing. An electrically conductive grease is then applied via the auxiliary bearing to the shaft of the bearing that is joined to the rotor shaft. A low resistance path to ground is thereby created for the dissipation of the unwanted shaft voltages and consequently prevents harm to the machine.

Abstract: A plastic tube and a method and apparatus for forming it in which a strip of relatively thin plastic sheet material is cut from a roll of the material and wound around a mandrel. Overlapping ends of the strip are sealed to form the tube. The edge of the strip is inwardly bent to form an inwardly extending lip. When used in the manufacture of a capacitor, the tube is placed in a can on top of the disc of insulating material and a capacitor roll is placed in the tube. The edge of the sheet material can be pre-creased so that when folded inwardly, darts of the material form the lip.

Abstract: A family of programmed start parallel-resonant electronic ballast circuits operate in a first mode during a preheat interval following application of power to the ballast, and then afterwards operate in a second mode. The ballast circuits can be based on any of the several forms of current-fed parallel-resonant inverters, all of which have a dc choke inductor. A first embodiment operates such that, during the first mode, the parallel-resonant inverter is inhibited, while an auxiliary transistor develops a trapezoidal voltage waveform across the dc choke inductor. Filament preheating is provided by windings coupled to the dc choke inductor. The ballast output voltage is essentially zero so that no destructive glow current is produced. During the second mode, the auxiliary transistor is inhibited, and the parallel-resonant inverter produces a sinusoidal output voltage.

Abstract: An one-piece plastic protective enclosure is provided for a glow bulb used as a starter for a fluorescent lamp. The enclosure has a latching hinged lid, a partition wall to isolate the glow bulb leads, and integral strain relief. The glow bulb enclosure is mounted inside a ballast assembly and the glow bulb leads are ultrasonically welded to the ballast power supply wires.

Abstract: A pulse-width modulator is disclosed which can be used, for example, in a power factor corrected electronic ballast circuit. The pulse-width modulator circuit combines a reference waveform signal with a second signal to form a composite waveform signal. The composite waveform signal is then compared with a reference voltage. The level of the pulse-width modulator's output depends upon the results of the comparison, such that a change in the level of the second signal causes an adjustment in the duty cycle of the output. In an electronic ballast application, the reference waveform can be a scaled version of the oscillator waveform found in the ballast's inverter circuit.

Abstract: A control circuit and ballasting means controls the light output of a gas discharge lamp in response to switches that are external to the ballast. The invention provides 3 levels of light output with single or multiple lamps. One embodiment of the invention can be mounted in a standard three-way socket for incandescent lamps. Another embodiment can be used to control multiple lamps in a ceiling-mounted fixture, replacing an inboard/outboard configured multiple ballast circuit. Other embodiments provide circuits that allow conventional dimming ballasts which are designed to be controlled with a low-voltage DC input signal to be controlled by a pair of switches connected to an AC power source.

Abstract: A control circuit provides, for connecting a motor to a d.c. voltage source (1), two half bridge (3, 7, 5, 9) each with a respective switch (3, 5) with controlled opening and closing; the first of the half bridge connects a pole of the excitation winding (13) to the source (1) and the second of the half bridge connects a pole of the armature (15) to the source (1). A control unit (11) controls the opening and closing of the two switches (3, 5) of the half bridge and the toggling of the reversing device as a function of the operating conditions of the motor. The control unit (11) is programmed in such a way that in the braking phase it toggles both of the controlled switches (3, 5) cyclically, simultaneously or independently, from an open condition to a closed condition and vice versa.

Abstract: A capacitor arrangement across a direct current bus provides a high ripple current capability and high capacitance at a low cost. The circuit is used in electronic power conversion devices such as electric motor drives and inverters. A combination of film capacitors and electrolytic capacitors are used in the circuit and are placed across the dc bus. The film capacitors carry substantially all of the ripple current, while the electrolytic capacitors provide the majority of the capacitance. A resistor and a diode are used to isolate the electrolytic capacitors from the ripple current. This results in a low cost compact bus capacitor configuration.

Abstract: An electrostatic shielding system is provided for an AC motor to eliminate generation of destructive motor bearing currents. Conductive end turn shields are layered over the stator coil end turns at each end of the stator. Conductive grounding clips mechanically and electrically engage the end turn shields at one end of the clip, and electrically and mechanically engage the slotted openings in the stator at the other end. Conductive strips extend longitudinally along the stator slotted openings.

Abstract: A low cost power supply with enhanced safety protection for neon lamps connected in a midpoint commoned lamp configuration. The power supply has a return path which is isolated from the earth ground so that a fault current does not flow from the output terminals to the earth ground. The windings are phased in a series opposing configuration such that the voltages between the output terminals sum to zero. This power supply of mid-point connected secondary coil design is capable of operating lamp lengths that typically require 15,000 volts of open circuit voltage while not exceeding 7500 volts to ground when any one output terminal is grounded.

Abstract: A housing having a main section for holding an object, such as a ballast transformer, that has side walls and an open top. A lid having a shape conforming to that of the housing main section has side walls that fit over the main section side walls and covers the open top. The lid has an integral bracket of general U-shape that extends from one of the edges of the lid with the open part of the U facing upwardly toward the lid top. The bracket permits the housing and its contents to be suspended from an external mount.

Abstract: The circuit for firing and supplying a discharge lamp, includes:a load circuit (10), with at least one discharge lamp (L) and a voltage supply for supplying a discharge lamp,a subportion of the circuit is in parallel with the lamp (L). This subportion includes at least one arrangement of capacitors (17, 21) and an inductive impedance which can be varied in a controllable manner in order to modify the value of the total impedance in parallel with the lamp.

Abstract: One half-connector terminates leads in the ballast, carrying electricity to and from the ballast coils. Another half-connector terminates leads outside the ballast, connected e. g. to carry power to lamp sockets. A hook extended from a first of the half-connectors engages a catch formed in a second. A retaining surface, preferably associated with the second half-connector, keeps the hook engaged with the catch. Preferably the space between the retaining surface and the catch is smaller than the unstressed dimension of the hook barb--but during the act of engagement the barb deforms to pass between the catch and surface; then the barb springs back into shape and is held behind the catch. In this process also preferably the retaining surface cooperates with the first half-connector to support the shaft or beam of the hook at both ends--as in a classical double-ended beam spring structure, contrasted with a cantilevered spring in a conventional hook and catch.

Abstract: A universal input dimming circuit for coupling an isolated external control signal into a variable output power supply, particularly those used for driving fluorescent lamps. Circuitry is incorporated which allows to discriminate between a DC control voltage or a relatively low-frequency pulsewidth-modulated signal using the same pair of input leads. By appropriate conditioning and waveshaping, the circuit produces a pulsewidth-modulated output which is then coupled across an isolation boundary and then demodulated to provide a command signal to the dimming ballast.

Abstract: A low cost power supply for neon lamps provides enhanced safety protection. The power supply has a transformer with a return path which is separate from the earth ground so that a fault current can be detected. The power supply has a mid-point connected secondary coil design which operates a mid-point connected neon lamp configuration. A protection circuit detects the fault current flowing between the output terminals and the earth ground. When the fault current is detected, the protection circuit disconnects the input power from the primary winding. An input power reset is required to restart the power supply once the protection circuit has operated.

Abstract: A drive circuit for a switched reluctance motor has phase circuits connected to a common dump capacitor which receives residual magnetic energy from each phase coil when it is switched off. One or more recovering phase circuits are connected to the dump capacitor and comprise a controlled switch and diode whereby energy stored in the dump capacitor is returned to a recovering phase coil in sequence.