Abstract: The invention relates to a current converter of the forward converter type for converting a three-phase primary voltage into a plurality of secondary voltages, with a magnetic intermediate circuit including at least three transformer secondary windings, wherein the current converter on its primary side includes at least three transformers with respectively two primary windings wound in opposition directions and respectively at least one secondary winding, and that two electronic switches are provided, wherein the first switch respectively controls a primary winding of the three transformers via a set of diodes and wherein the second switch respectively controls another primary winding of the three transformers via a second set of diodes.

Abstract: The invention relates to a current converter of the forward converter type for converting a three-phase primary voltage into a plurality of secondary voltages, with a magnetic intermediate circuit including at least three transformer secondary windings, wherein the current converter on its primary side includes at least three transformers with respectively two primary windings wound in opposition directions and respectively at least one secondary winding, and that two electronic switches are provided, wherein the first switch respectively controls a primary winding of the three transformers via a set of diodes and wherein the second switch respectively controls another primary winding of the three transformers via a second set of diodes.

Abstract: A power supply for use in a UV curing lamp assembly is disclosed. The power supply is powered by two intermediate frequency (200-400 Hz) low voltage sinusoidal power sources that drive the primary windings of a dual laminated transformer. The low voltage sinusoidal power sources are configured to have different phases. The out-of-phase low voltage sine wave sources are converted to high voltage sine waves on the secondary windings of the dual laminated transformer having the same phase difference relationship. A single rectifier comprising six high voltage diodes, called a ladder rectifier, combine the two out-of-phase sine waves into a single, approximately DC output power source. By modulating a phase difference between two input sine wave power sources, the approximate DC output voltage exiting the ladder rectifier may be alternated between a low ripple mode of about a 13.84% ripple, a high current mode, a high voltage mode, and an intermediate mode with a ripple in the range of about 13.84% to about 100%.

Abstract: A method and apparatus for providing power in an electrical system is disclosed. The electrical system comprises: a poly-phase electrical source; a plurality of transformers coupled to each other, where each phase of the poly-phase source is coupled to a transformer within the plurality. The electrical system further comprises a plurality of loads, where each load is coupled to a tap point on one of the transformers and where the transformers are capable of being severed at their common connections and coupled to a neutral line.

Abstract: A lighting system and method (1) is disclosed having a pulse-width modulation (PWM) lighting system and method for use in environments where the PWM ratio is variable, for example though not exclusively, in 42V and/or dual-voltage electrical systems in automotive applications.

Abstract: The inventive control circuit 40 serves to render the output voltage to be the output value of any one of the outputs OUT1 to OUT5 when both the main power source A of the power saving device 100 and the control circuit's switch B are in ON state, and to maintain the output value to be constant by the operations of the comparator, CPU or the like in the control circuit 40. In addition, if the input voltage or input current is excessively high or low, the control circuit 40 can cut off the voltage or current, so that the protection device 100 can be protected from abnormal voltage or abnormal current.

Abstract: The inverter for multi-tube type backlight includes two step-up transformers of one-side grounded type, wherein the two step-up tranformers respectively output electric power to one or a plurality of cold cathode tubes, and wherein outputs of the two step-up tranformers are of identical frequency but of mutually reversed phases.

Abstract: A lamp ballast for energizing a lamp has short circuit protection. The lamp ballast contains a transformer that provides an output voltage to the lamp. The transformer has a primary winding, a secondary winding, and a third sense winding. The third sense winding has an output that provides an indication of transformer output voltage. A reference voltage circuit creates a reference voltage that provides an indication of a non-short circuited lamp ballast condition. A comparator compares the reference voltage and the output of the third sense winding to provide an indication if the third sense winding output is below the reference. This indicates if there is a short in the output of the lamp ballast. The secondary is wound on multiple sections of a bobbin with one section being a low voltage section. The sense winding is wound under the secondary in the bobbin secondary low voltage section.

Abstract: A transformer unit connects to an ac outlet and provides ac controlled by an opto-coupled triac to another ac outlet. The transformer unit includes a transformer and a third connector for connection to a control unit separate from the transformer unit. The third connector provides the control signal from the control unit, a low voltage supply for the control unit derived from the transformer, and the timing of the ac waveform, provided by a zero crossing signal or an ac or rectified ac signal which can constitute the low voltage supply. The control unit, electrically isolated from the ac supply, can produce the control signal under manual control or automatically to gradually change the conduction phase angle of the triac. The brightness of a lamp connected to the ac outlet is thereby controlled manually or automatically to provide a simulated dawn or dusk.

Abstract: This invention relates to a supply device for discharge lamps, which comprises, for each lamp:

Abstract: A discharge-lamp illumination circuit has a DC power supply circuit, a DC-AC conversion circuit, and a control circuit for controlling a voltage from the DC power supply circuit. The DC power supply circuit has a transformer and a first switching element connected in series with a primary coil of the transformer. The activation/deactivation of the first switching element is controlled by the control signal from the control circuit. The transformer is equipped with secondary coils equal in number with the discharge lamps. Each secondary coil is equipped with a second switching element whose activation or deactivation is controlled by a signal from the control circuit. The secondary coils provide different voltages by means of control of the second switching elements.

Abstract: An electronic ballast for at least one low-pressure discharge lamp contains an inverter which is connected to a direct-voltage source (UBUS), a load circuit which is connected to the inverter and contains the lamp (LA) and a series resonant circuit, and an evaluating circuit arrangement (M1) which reacts to different operating states of the lamp (LA) and in the case of a defect or removal of the lamp (LA) generates corresponding signals which are used to switch off the inverter. Provided for the purpose of heating the coils (W1, W2) there is a heating transformer, the primary winding (Tp) of which is connected in series with a switch (S3) to the output of the inverter and in any case is connected to the direct-voltage source (UBUS) if the inverter is switched off on account of the heating-coil defect or the removal of the lamp (LA), with the switch (S3) being clocked in this off-phase.

Abstract: A small package voltage reduction system which is especially adapted for easy installation into a conventional high intensity discharge light, such as a street light having a receptacle for receiving a standard ambient light sensor. The invention permits extremely easy and thus inexpensive installation and maintenance and yet provides a significant reduction in energy use which may save significant expenditure for energy by a municipality or other user of high intensity discharge lights.

Abstract: Disclosed is a ballast circuit arrangement for a gas discharge lamp, which includes a ballast transformer arrangement receptive of an input power signal, having a winding and a serially connected ballast capacitor, and providing an output, ballast voltage that alternates in polarity during successive half cycles. A bypass capacitor is coupled to the winding of the ballast transformer for being charged by the ballast voltage. A voltage for driving the lamp exists on the bypass capacitor. The inventive arrangement includes a pulse transformer having a secondary winding in serial circuit with the lamp for impressing a high voltage, hot restrike starting pulse across the lamp. A hot restrike starting circuit is provided, comprising a starting capacitor coupled across the bypass capacitor, and a circuit for discharging the starting capacitor including a primary winding of the pulse transformer and a serially connected current switch.

Abstract: A spark gap device is disclosed that is particularly suited for a rapid restrike or starting circuit which is employed in sport stadium lighting applications to start or restrike metal halide lamps that have been subjected to a momentary loss of power. The spark gap device comprises two electrodes that are arranged in a parallel side-by-side relationship and spaced apart from each other by a predetermined amount. The spark gap device operates that when a high voltage potential is applied across the electrodes, the generated and reoccuring spark is distributed along the parallel arranged electrodes. The parallel arrangement of electrodes provides for improved life and cooler electrode temperatures as compared to prior art spark gap devices in which the generated and reoccuring spark jumps between the end regions of separated electrodes.

Abstract: A circuit for the electrical supply of a plurality of electron beam evaporators has application in heat and thermochemical treatment processes such as welding, fusing, zonal cleaning of materials, dimensional treatment, application of coatings, etc. A multi-phase step-up transformer is connected to the output of a voltage regulation unit. One of the outputs of each phase of the secondary winding of the transformer, as well as the processed material and the anodes of the electronic beam evaporators are grounded. The deflection and focusing lenses of the evaporators are connected to the outputs of an electron beam control unit and the other outputs of each phase of the secondary winding of the transformer are directly coupled to the cathode of the respective evaporator and, across a voltage and current transformation unit, to the inputs of the electron beam control unit.

Abstract: Apparatus for sequentially igniting and serially operating a pair of electric discharge lamps from a source of AC supply voltage. The apparatus includes a transformer with a primary winding and first and second secondary windings mounted on a magnetic core having a slot under the second secondary winding. The first secondary winding has a high leakage reactance and the windings are serially connected with the secondary windings wound in opposition to one another. First and second capacitors are connected in series with the first and second lamps, respectively, to prevent the flow of DC current therethrough. By a novel choice of the ratios of the capacitance values of the second capacitor to the first capacitor and of the slot dimensions, superior operating characteristics for the apparatus are achieved.

Abstract: A voltage controller for use with a fluorescent-lighting system, the controller including a three-phase transformer having three auto-transformer windings each for developing two reduced voltages, three contactors for selectively coupling the full voltage and the reduced voltages to the lighting system, the contactors being switched in closed-transition fashion to avoid power interruptions, and another contactor for opening the winding-neutral connections during voltage switching to avoid shorting the transformer.

Abstract: An apparatus for reducing the voltage applied to a load in an AC system utilizes an autotransformer and a relay or equivalent switching device between the common winding and the series winding. In each of the AC lines, the common winding and relay are connected between the load and the AC common while the series winding is connected between the input and the output. The relay is normally open to pass substantially full input voltage to the load, but when closed the relay permits current flow in the common winding to reduce voltage to the load. The relay or equivalent switching is therefore not in the direct flow of load current and can be of lower current rating and smaller size and cost as compared to prior art voltage reduction systems.

Abstract: A high power tube in applications requiring reduced AC hum in the amplified signal, utilizes a direct current heated filament. In order to reduce the incidence of tube failure and maintain a stable mode of operation, the direct current is produced by a regulated source of DC voltage. The regulated source includes a transformer having a primary winding coupled to a source of alternating line voltage and also includes a secondary winding at which a transformed low voltage is generated. A rectifier is coupled to the secondary winding for rectifying the transformed voltage to produce a pulsating direct voltage which is applied to the tube filament by a filter. The primary winding of the transformer is coupled to the AC source by means of a saturable reactor. A control circuit senses the voltage across the filament and controls the reactor in a feedback manner.

Abstract: The power supply for an airborne pulse radar includes an unfiltered source of 400 cycle AC power connected to a full wave rectifying circuit including two diodes associated with each phase of the three phase input circuit. In addition, three SCR's are employed for controlling the operation of the rectifiers. During normal operation of the pulse magnetron power supply, the control electrodes of the SCR's are biased to the conducting or enabled state by a small floating DC voltage which is obtained from a small DC power source which includes a rectifier circuit connected to the floating secondary of a low voltage transformer. When a fault is sensed in the magnetron pulse circuitry as indicated by the drawing of excessive current, a switching circuit is activated which removes the enabling voltage across the SCR's, so that the input rectifier circuitry is disabled, thus preventing burn-out of components included in the pulse generation circuitry.