Abstract: A backlight inverter for an LCD panel which is capable of detecting a fault in a transformer device or an open-lamp condition and performing a control operation to stop its operation upon detecting the fault in the transformer device or the open-lamp condition. The inverter supplies a PWM signal through a switch in normal operation. The inverter also detects a voltage corresponding to current flowing through each lamp in a lamp device and determines from the detected voltage whether the open-lamp condition has occurred. The inverter further detects a voltage at a midpoint of secondary windings of the transformer device and determines from the detected voltage whether the fault exists in the transformer device. In the event of the open-lamp condition or the fault in the transformer device, the inverter turns off the switch.

Abstract: To efficiently and cost-effectively produce a light source, a CCFL circuit can include a PMOS transistor, first and second NMOS transistors, and a high turns ratio transformer. The transformer can include a primary coil having a center tap, thereby forming first and second primary windings, as well as a secondary coil. The PMOS transistor can be connected to the center tap for driving the transformer. The first and second NMOS transistors can be connected to the first and second primary windings, respectively. Of importance, the first primary winding is tightly coupled to the second primary winding, whereas the first and second primary windings are loosely coupled to the secondary coil.

Abstract: A power supply system is provided for a multiple lamp LCD panel. In one aspect, the power supply includes a plurality of transformers for driving a plurality of respective CCFLs. The primary sides of each transformer are coupled in series to thereby reduce the stress on each transformer. For LCD panels that include longer CCFLs, a power supply is provided that includes a plurality of transformers for driving a plurality of respective CCFLs. The primary sides of each transformer are coupled in series and each lamp is coupled to two secondary sides of the transformers, thereby reducing the problems associated with longer CCFL tubes. In any of the embodiments, the power supply can be adapted to convert a high voltage DC signal to high voltage AC used to power the lamps.

Abstract: Disclosed is an electronic ballast for a fluorescent lamp having a high capacitance capable of turning on lamps of different capacitances (36W, 18W), or selectively two lamps of the same capacitance or one lamp, using one circuit, by replacing a lamp driving unit with an integrated circuit (IC).

Abstract: A ballasting circuit is configured with a circuit having a capability of providing an isolated power supply to various external ballast accessories that interface with a circuit or device for determining the amount of illumination. The ballasting circuit also has a capability of providing isolated power for circuitry within itself such that they can be connected to communication wires external to a lighting fixture without the need of an additional power supply. The ballasting circuit includes one or more gas discharge lighting devices, a source of input power, an electronic ballasting circuit having a regulated direct current requirement and coupled between the one or more gas discharge lighting devices and the source of input power, a heater transformer, a low voltage direct current power supply, a switching device, a regulator circuit, a full wave rectifier, and windings.

Abstract: An energy-saving light marking device with low power consumption including a head transformer (10) where the primary winding (12) is powered by an alternating current source and several marking lamps in series (14-1 to 14-3) connected to the terminals of the secondary winding (13) of the head transformer, each of the marking lamps being a fluorescent lamp (16-1 to 16-3) powered by the secondary winding of a second transformer (18-1 to 18-3), the primary windings of all the secondary transformers of the marking lamps being connected in series between the terminals of the head transformer's secondary winding (13). The starting of each of the fluorescent lamps (16-1 to 16-3) is provided by the voltage surge generated at the terminals of the secondary winding of the secondary transformers (18-1 to 18-3) when the primary winding of the secondary transformers is powered while the lamps are not yet started.

Abstract: A airport runway lighting system, including a power source (10) supplying a constant current to a primary circuit (12) and several marking lights (14-1 to 14-6) each being connected to the primary circuit by a current transformer (16-1 to 16-6), the secondary winding of which supplies the lamp current. At least several adjacent transformers form a multiple assembly without a connection cable. Each transformer features a built-in male connector and a female plug or two built-in female plugs. The transformers are stacked to form the multiple assembly, the male connector of one of the transformers being inserted into the female plug of the immediately adjacent transformer, the male connector of the first transformer and the female plug of the last transformer being connected in series to the primary circuit.

Abstract: A discharge lamp lighting device comprises a plurality of discharge lamps, at least one reflector, and at least one leakage transformer. Each leakage transformer lights three discharge lamps and comprises: a first leakage transformer, which comprises a frame-core shaped substantially rectangular and two bar-cores disposed parallel to each other and orthogonal to two opposing sides of the frame-core with a predetermined gap from the frame-core, has two of primary and secondary windings structurally independent of each other, and which lights two discharge lamps of the three; and a second leakage transformer, which comprises a frame-core shaped substantially like square-U letter and a bar-core disposed orthogonal to two opposing sides of the frame-core with a predetermined gap from the frame-core, has one primary and secondary winding structurally independent of each other, and which lights remaining one discharge lamp.

Abstract: A hot-restrike ignition system for a high-frequency high-intensity discharge lamp includes a resonant circuit that is connectable across the lamp in parallel with a ballast circuit that is used to provide steady-state current for the lamp. The resonant circuit is temporarily energizable for producing a voltage sufficiently high for hot-restrike ignition of the lamp. The resonant circuit has two parts. The first part provides a voltage waveform with frequency approximating the steady-state voltage frequency and amplitude sufficient when combined with the steady-state voltage to produce glow discharge, and the second part provides a voltage waveform that is lower in repetition rate but of sufficiently high voltage to initiate hot-restrike ignition in the lamp.

Abstract: A power supply apparatus of a lighting system using microwave includes: a high voltage transformer for transforming a general AC power to an AC power of high voltage and outputting the high voltage AC power; and a voltage doubler unit for transforming the high voltage AC power into a high voltage DC power, increasing the frequency of the current of the DC power, and outputting the DC power having the increased frequency. Since the frequency of the power applied to the magnetron is increased to remove the flicker phenomenon, a stable light can be radiated to an external space.

Abstract: In a discharge-lamp lighting circuit for turning on a plurality of discharge lamps, starting circuits 8 for supplying starting pulses to the respective discharge lamps are provided. Each starting circuit 8 has transformers T1 and T2 equal in number to the discharge lamps and each of the transformers has a primary and a secondary winding. The discharge lamps 6—1 and 6—2 are connected to the respective secondary windings T1s and T2s. Capacitors C1 and C2 are connected to the respective primary windings T1p and T2p of the transformers and one switch element SW is provided in a circuit including the primary windings and the capacitors. When the accumulated charge in each capacitor is discharged via the primary winding of the transformer as the switch element SW conducts, the starting pulse is generated and supplied to each discharge lamp via the secondary winding of each transformer.

Abstract: A ballast circuit with an ignitor circuit for starting serially connected HID lamps is provided. The ballast circuit comprises an electromagnetic ballast arrangement for driving the lamps and an ignitor circuit for starting the lamps. In an embodiment of the invention, the ignitor circuit comprises a voltage-breakover device, a first capacitor, a resistor, a pulse autotransformer, and a second capacitor. A pulse autotransformer is associated with each subsequent lamp after a first lamp of the serially connected lamps.

Abstract: Two high-pressure discharge lampbanks and transformers thereof are connected via a cross connection manner. The two lamp banks include the same number of high-pressure discharge lamps, and the transformers are in a number corresponding to that of lamps in each lamp bank. All the transformers have two outputs, namely, first and second outputs, at a secondary side thereof. First outputs of all the transformers are separately connected to the lamps in a first one of the two high-pressure discharge lamp banks while second outputs of all the transformers are separately connected to the lamps in a second one of the two high-pressure discharge lamp banks. Thereby, lamps in the same lamp bank are maintained at a voltage having the same phase and have a small potential difference among them to avoid interference noises.

Abstract: A driving apparatus of a discharge tube lamp includes a voltage source; a plurality of AC conversion circuits for boosting a voltage supplied from the voltage source and generating a plurality of boosted AC signals; a plurality of discharge tubes for receiving the boosted AC signals and emitting a plurality of lights; a plurality of detection circuits arranged between each of the plurality of AC conversion circuits and a ground voltage source for detecting a voltage supplied to each of the plurality of discharge tubes; and a controller arranged between the voltage source and each of the plurality of the AC conversion circuits for controlling the voltage supplied to the plurality of AC conversion circuits in accordance with a plurality of detection signals supplied from the plurality of detection circuits.

Abstract: A flash lamp for underwater photography has at least two straight discharge tubes mounted to a panel perpendicularly to each other in a T-form or an L-form such that a circular target area can be illuminated. A plurality of smaller capacitors and transformers for these discharge tubes can be arranged inside a watertight housing in a space-efficient manner. The mode switching circuit for selecting between automatic and manual modes of operation is designed such that a single mode selecting switch needs to be operated in order to select a mode. A slave flash lamp has a more reliable control circuit having one or two light receiving circuits for detecting light from a master and outputting a corresponding light sensing signal, a start signal output circuit and a stop signal output circuit for analyzing the received light signal and analyzing it to detect start and stop signal elements and to output a start signal and a stop signal for causing flash light to start emission and to stop it.

Abstract: A unique drive circuit for a fluorescent lamp, as well as a housing for such lamp and drive circuit, are designed for mineral museum displays. The drive circuit comprises a ballast subcircuit, a separate filament transformer subcircuit for pre-heating the lamp cathodes, and a relay between the subcircuits. The separate filament transformer subcircuit obviates the need for a conventional starter circuit for the fluorescent lamp. This way of pre-heating the cathodes prolongs the useful life of the lamp by making it possible for the lamp to undergo thousands of “on-off” cycles without the heretofore usual deterioration of the cathodes. The relay prevents the high voltage of the ballast from “hitting” the lamp cathodes before the cathodes have been pre-heated by the transformer subcircuit. Also a method is designed for using such a lamp, drive circuit, and housing to irradiate fluorescent minerals in a display case.

Abstract: An electronic ballast for a gas discharge lamp has a power source section for receiving a commercial AC to provide a DC voltage, and an inverter section, in response to a pair of switching driving signals, for switching and transforming an output voltage of the power source section at a high speed as an AC power source that is supplied to the gas discharge lamp. For controlling the switching of the inverter section, an inverter controlling section generates a pair of switching driving signals respectively having a predetermined dead time in a switching-ON time interval with a phase difference of 180 degrees from each other to supply them to the inverter section.

Abstract: A description is given of an operating method for a discharge lamp with dielectrically impeded discharges and also a corresponding ballast and illumination system. The invention is directed at withdrawing the external lamp voltage across the discharge lamp in order to produce a back ignition in the lamp by virtue of an internal counterpolarization. The back ignition improves the efficiency of the lamp operation and makes it possible to construct a very small, lightweight ballast.

Abstract: A pulsed high voltage power supply for use in a radiography system includes a high voltage step up transformer having a primary winding with first and second ends and a secondary winding connected to a radiation source. The power supply further includes a low voltage power source coupled to the first end of the primary winding and a switching circuit coupled to the second end of the primary winding. The switching circuit generates a switching signal having a series of pulses such that each pulse from the series of pulses causes the high voltage step up transformer to generate a high voltage pulse across the first and second electrodes to form a series of substantially uniform high slew rate high voltage pulses across the first and second electrodes of the radiation source.

Abstract: A pulsed high voltage power supply for use in a radiography system includes a high voltage step up transformer having a primary winding with first and second ends and a secondary winding connected to a radiation source. The power supply further includes a low voltage power source coupled to the first end of the primary winding and a switching circuit coupled to the second end of the primary winding. The switching circuit generates a switching signal having a series of pulses such that each pulse from the series of pulses causes the high voltage step up transformer to generate a high voltage pulse across the first and second electrodes to form a series of substantially uniform high slew rate high voltage pulses across the first and second electrodes of the radiation source.

Abstract: A dimming system and method suitable for any type of magnetic ballast operating a gaseous discharge lamp. The dimming system operates to selectively vary the number of turns of the ballast winding in operative connection with the lamp to thereby effect a change in the impedance of the ballast, the power provided to the lamp, and ultimately the brightness of the lamp. The system may be operated such that the brightness of the lamp is selected responsive to the detection of an external stimulus such as motion or sound within the space to be illuminated.

Abstract: A flash lamp for underwater photography has at least two straight discharge tubes mounted to a panel perpendicularly to each other in a T-form or an L-form such that a circular target area can be illuminated. A plurality of smaller capacitors and transformers for these discharge tubes can be arranged inside a watertight housing in a space-efficient manner. The mode switching circuit for selecting between automatic and manual modes of operation is designed such that a single mode selecting switch needs to be operated in order to select a mode. A slave flash lamp has a more reliable control circuit having one or two light receiving circuits for detecting light from a master and outputting a corresponding light sensing signal, a start signal output circuit and a stop signal output circuit for analyzing the received light signal and analyzing it to detect start and stop signal elements and to output a start signal and a stop signal for causing flash light to start emission and to stop it.

Abstract: The present invention provides a CCFL driving circuit having a parallel-arranged transformer system and a feedback loop positioned to sense the current in one of the lamps in the system. Each CCFL in the system is driven by the secondary side an individual transformer. Based on the current sensed in the feedback loop, a controller supplies the appropriate driving voltage to the primary side of the transformers, which in turn powers each CCFL. Since the primary sides of the transformers are arranged in parallel, and since each CCFL is connected at a common node, it is ensured that each transformer receives identical voltage, and the current in each CCFL loop is balanced.

Abstract: Control circuitry causes a fluorescent lamp to flash by cycling the primary of the lamp ballast reactor at a desired cycle rate. This results in the average lamp wattage output being generally about 40% to 60% Go its normal wattage rating. This results in a correspondence reduction in lumen output. In such flashing, the intensity or light output of each flash is approximately the same as its normal, continuous light output.

Abstract: A driving circuit of the present invention includes first and second piezoelectric transformers 12, 14 for outputting a voltage at a secondary terminal which is input from a primary terminal utilizing a piezoelectric effect, frequency control means 21 for outputting a frequency signal for operating the first piezoelectric transformer 12 at a required frequency voltage, phase reversing means 16 for reversing a phase of the frequency signal by 180 degrees, driving circuits 13, 15 for applying a frequency voltage to each of the piezoelectric transformers 12, 14 based on these frequency signals of which phases are different from each other by 180 degrees, a discharge tube 11 in which an output of the first piezoelectric transformer 12 is applied to a first input terminal and an output of the second piezoelectric transformer 14 is applied to a second input terminal, a circuit 20 for controlling a voltage of the first piezoelectric transformer 12 so that a current flowing in this discharge tube becomes to be consta

Abstract: Electronic ballast system for fluorescent lights. A power oscillator connected to the primary winding of a power transformer for operation at a predetermined frequency in the range of 10 KHz to 5 MHz, and a ballasting network is connected to the secondary winding of the transformer and to one or more fluorescent lamps. The ballasting network is resonant at a frequency within about .+-.10 percent of the predetermined frequency, and in some embodiments, the resonant frequency of the ballasting network remains the same regardless of the number of lamps connected to it.

Abstract: A ferroresonant ballast for regulating the current level of gas discharge lamps includes a magnetic core for supporting coil windings. A first or input coil is wound about the magnetic core for supplying a changing input voltage. A second or capacitor coil is wound about the magnetic core and is induced by the first coil to generate an output voltage across an output or resonant capacitor. A third or lamp coil is wound about the magnetic core and coupled to a gas discharge lamp which is regulated at a constant voltage in response to the voltage generated across the output capacitor. The ferroresonant ballast may include a control circuit and inductor that is switchable coupled to the output capacitor for simulating core saturation.

Abstract: An apparatus for controlling illumination of a fluorescent lamp is disclosed which includes two transformers for heating cathodes of the fluorescent lamp. Also included are two ballasts for ballasting the fluorescent lamp having an input adapted to receive a source of A-C power and an output coupled to the fluorescent lamp. The ballasts provide power to the fluorescent lamp in excess of a normal rated power of the fluorescent lamp. The apparatus further includes a flasher relay for repeatedly cycling power at a cycling rate between power on and power off to the fluorescent lamp coupled to the output of the ballasts and to the fluorescent lamp, thereby causing the fluorescent lamp to flash at a flashing rate with a flashing intensity of light output which is greater than the flashing intensity of output of the fluorescent lamp under normal continuous operation. A remote control sensor may be connected to the apparatus to switch the apparatus between the flashing cycle and normal continuous operation.

Abstract: In an inverter circuit including a piezoelectric transformer (17) for supplying a voltage signal to a cold-cathode tube (50), a driver (12) for driving the piezoelectric transformer, a voltage-controlled oscillator (11) for producing an oscillation pulse voltage signal having an oscillation frequency controlled by a control voltage, a phase difference detection circuit (15) for detecting as a detected phase difference a phase difference between input and output voltage signals of the piezoelectric transformer, and a control circuit (16) for producing the control voltage so that the detected phase difference is coincident with a predetermined value, a current detection circuit (21) detects as a detected current value a current which flows through the cold-cathode tube. Supplied with the oscillation pulse voltage signal and the detected current value, a power control section (22) controls an electric power of the oscillation pulse voltage signal so that the detected current value has a preselected value.

Abstract: A power supply quickly restarts an electrodeless lamp which is temporarily turned off in an application using microwave radiation generated by a magnetron. When the electrodeless lamp operates in a full power mode, the power supply provides full power to the magnetron via high DC current and high DC voltage. When a user selectively switches the electrodeless lamp off, less power is provided to the magnetron than in the full power mode. In the reduced power mode, the magnetron generates sufficient microwave radiation to maintain the bulb plasma in an ignited condition while the lamp produces substantially no light output. This eliminates the required cooldown delay associated with the lamp shut down and quickly brings the lamp to the full power operation when requested by the user.

Abstract: A ballast includes safety circuitry which senses lamp status through various phases of ballast operation. According to one feature, the ballast is prevented from supplying an output voltage upon initial energization of the ballast when a lamp is not present at the output terminals. The presence of a filament is sensed via a DC path extending through the filament heater windings of an output transformer. When the DC path is not complete, a control input, for example the power supply input of the ballast controller, is not provided with a voltage to start ballast operation. The DC path is also used to restart the ballast if a defective lamp is replaced with a good one. Over-voltage and capacitive mode detection is also disclosed to shut down ballast output upon lamp failure/removal.

Abstract: A single-stage modular modulator for pulsed illumination sources uses a full-range converter which converts unregulated DC to a 40-50 kHz carrier modulated at a frequency of a few hundred to a few thousand hertz. The modulated carrier is applied to the illumination source through a step-down transformer followed by a low-pass filter circuit which removes the carrier. The converter is controlled by a modulation control which uses an instantaneous load current signal feedback to follow a modulation commend signal, and a current mode signal representing the primary current of the transformer to compensate for converter output variations caused by input voltage variations.

Abstract: A ballast includes safety circuitry which senses lamp status through various phases of ballast operation. According to one feature, the ballast is prevented from supplying an output voltage upon initial energization of the ballast when a lamp is not present at the output terminals. The presence of a filament is sensed via a DC path extending through the filament heater windings of an output transformer. When the DC path is not complete, a control input, for example the power supply input of the ballast controller, is not provided with a voltage to start ballast operation. The DC path is also used to restart the ballast if a defective lamp is replaced with a good one. Over-voltage and capacitive mode detection is also disclosed to shut down ballast output upon lamp failure/removal.

Abstract: Circuit arrangements generate start, glow, and/or run signals to be applied to and for operating a DC arc discharge lamp. A first circuit arrangement provides start, glow, and run signals. The first circuit arrangement includes a tapped transformer flyback converter circuit for combining the start and glow functions; a buck/boost converter for providing the run function; and blocking diodes for providing a blocking function for the glow circuit during the start and run modes, and further for providing a blocking function for the run circuit during the start and glow modes. A second circuit arrangement provides start and glow functions, and includes a tapped transformer flyback converter circuit for combining the start and glow functions; and a blocking diode for providing a blocking function for the glow circuit during the start mode. A third circuit arrangement includes a buck/boost converter for providing glow and run functions, and further includes an inductive storage element, such as an inductor.

Abstract: An electrical arrangement is disclosed comprising a circuit to supply current to a discharge lamp. The circuit comprises a lower voltage source of alternating current in the form of a square wave generator. The current is fed to two transformers, the primary windings of which are connected in series, the transformers being physically located immediately adjacent the electrodes of a discharge tube. The secondaries of the transformers are also connected in series, and are connected to the electrodes of the discharge lamp. Only extremely short high-tension leads are provided extended between the secondaries of the transformer and the electrodes. Each transformer is a transformer having a coupling factor in excess of 0.

Abstract: A lamp system including an alternating current power source for supplying a signal voltage, an input transformer having primary and secondary windings connected to the power source for increasing signal voltage, a signal rectifier connected to the secondary winding for creating a direct current signal from the increased signal voltage, a signal oscillator connected to the signal rectifier for creating a high-frequency signal from the direct current signal, one or more ballasts connected to the signal oscillator to create high-voltage high-frequency signals from the direct current signal, one or more lamps driven by the high-voltage high-frequency signal from the ballasts, a sense winding on an output side of each of the ballasts for inducing alternating current signals, an apparatus for receiving and processing the alternating current signals, and an apparatus for displaying the processed alternating current signals.

Abstract: Ballasting system for fluorescent lamps having improved energy transfer capability and which delivers a sinusoidal current waveform free of high order harmonics and induces a similar waveform into the power distribution system. The system includes a low leakage reactance auto-transformer which is tuned to the line frequency, and a separately-wound heating transformer and means for switching energy from the heating transformer each half cycle.

Abstract: An electrical arrangement is disclosed comprising a circuit to supply current to a discharge lamp. The circuit comprises a lower voltage source of alternating current in the form of a square wave generator. The current is fed to two transformers, the primary windings of which are connected in series, the transformers being physically located immediately adjacent the electrodes of a discharge tube. The secondaries of the transformers are also connected in series, and are connected to the electrodes of the discharge lamp. Only extremely short high-tension leads are provided extended between the secondaries of the transformer and the electrodes. Each transformer is a transformer having a coupling factor in excess of 0.

Abstract: A discharge lamp lighting apparatus comprises a transformer for stepping up an AC power source voltage from an AC power source to produce a high voltage as an output voltage required for lighting a discharge lamp. Particularly, the lighting apparatus further comprises a diode for rectifying the output voltage of the transformer to be supplied to the discharge lamp. The amount of current supply from the AC power source is determined to obtain an output impedance capable of limiting the current which is to flow through the discharge lamp after the start of discharging to maintain the voltage across the discharge lamp at a level required for continuing the discharge.

Abstract: A dimming system for a discharge lamp has a magnetic regulator with first, second and third windings linked by a magnetic core, the first winding being connectable to a source of alternating current. The second winding and a starting circuit are connected to the lamp for lighting the lamp. The third winding is tapped and has a ballast capacitor connected across the winding. An inductive reactor and relay contact set are connected in series between one end of the third winding and the tap so that when the contact set closes, the reactor stores energy from the source and reduces the power to the lamp, abruptly reducing its light output. A motion-responsive detector is used to energize the relay. With a normally closed contact set, the lamp is dimmed until a moving person is detected, opening the contact set and increasing the lamp light output. Multiple lamps can be controlled simultaneously.

Abstract: The ballast is connected between the fluorescent lights and a source of power for the fluorescent lights. The source of power provides an input signal having a first waveform, usually a sine wave, at a first frequency. The ballast consists of a converter for coverting the first waveform to a second waveform at a second frequency different from the first frequency. A distribution arrangement distributes power to the fluorescent lights. The distribution system consists of a transformer, and capacitors are interposed between selected windings of the secondary of the transformer. In one embodiment, the sine wave is converted to a square wave by the converter and to a saw tooth waveform by the capacitors in the distribution arrangement so that the fluorescent lights are fed with the saw tooth waveform.

Abstract: A circuit, including an electrical load such as a fluorescent lamp, energized through an inverter which is in turn energized from a standard household alternating current voltage source. The output of the inverter is of a low voltage, low current and high frequency. This power is then transmitted by a low current voltage link, in the form of a flexible small gauge, jacketed wire conductor connected across the outputs of the inverter, to the input terminals of a compact step-up transformer located a distance away from the inverter. The power created by the step-up transformer is converted to usable power by the electrical load. The low voltage link need not be enclosed in a raceway.

Abstract: A control system for lighting a bank of fluorescent lamps, includes input terminals (10, 11) for a mains voltage (e.g. 240 v) and output terminals (20, 21) to which the bank of lamps is connected. A transformer (T1) provides a reduced voltage (216 v) as compared to the mains supply voltage. The transformer (T2) provides a supplementary voltage (24 v). Upon start up of the circuit, a control circuit (CC) operates contact (A1) to energize the transformer (T2) so that terminals (20, 21) receive both the reduced voltage from (T1) and the supplementary voltage from (T2) (i.e. 240 v) which is sufficient to ignite the fluorescent lamps. The control circuit (CC), after a predetermined delay (e.g., 15 seconds), switches contact (A1) to disconnect the supplementary voltage from (T2). The lamps then continue to operate on the reduced voltage (216 v) thereby reducing the power consumed by the lamps.

Abstract: A ballast control apparatus for an electric discharge lamp comprises a first series circuit including a first winding of an AC supply voltage transformer, a first winding of a ballast transformer, a lamp current sensing resistor and the lamp. A current sensing transformer has a first winding parallel to the resistor. A second winding of the supply voltage transformer, the ballast transformer and the current sensing transformer are connected in a second series circuit. A signal voltage proportional to lamp power is derived by adding together the voltages induced in the three series-connected second windings. A second signal voltage proportional to lamp voltage is derived across the series combination of the second windings of the ballast transformer and the supply voltage transformer. The voltage induced in the second winding of the current sensing transformer is proportional to lamp current.

Abstract: A power circuit for N series connected loads according to the present invention includes N transformers having primary windings connected in series across a constant current AC source and secondary windings connected in series with the N loads. N-1 conductors are coupled from a junction between the loads to a corresponding junction between the secondary windings. Failure of one of the loads resulting in an open circuit will not interrupt power to the remaining loads.

Abstract: A power supply for outdoor lighting systems accepts ordinary household alternating current of 120 volts at 60 hertz. The power supply uses a digital switching means to convert this current into a lower voltage at a higher frequency. Typically, these values are 28 volts at 20 kHz. This high frequency signal is then supplied to the lights through a transformer. The use of a higher voltage than that normally used for such systems improves the operating efficiency of the lighting system and allows lights to be placed at a greater distance from the power supply. The higher frequency signal reduces the bulk and cost of the transformer. The voltage and current supplied to the lights can be altered by changing the frequency of the signal entering the transformer. A feedback circuit monitors the signal supplied to the lights and automatically varies the frequency so as to keep the voltage and current within predetermined operating limits.

Abstract: A regulator circuit for a high intensity discharge lamp includes a magnetic regulator having three windings, the primary and second thereof being connected to line voltage and a lamp. The tertiary winding is connected to a storage capacitor and to a reactor circuit having an inductive reactor and a semi-conductor switch in series. Lamp voltage and current signals are derived by a control circuit which turns the semi-conductor switch on at specific times in each half cycle of operation. The firing angle of the switch is altered to regulate the lamp operating characteristics despite line voltage changes and operating voltage variations resulting from lamp aging and other factors. The control circuit can also be operated as a lamp dimmer circuit.

Abstract: A high voltage transformer assembly for use in a high frequency medical X-ray generator comprises a plurality of transformers, a plurality of filter capacitors, and a pair of capacitor printed circuit boards for mounting the capacitors and for coupling the capacitors in electrical circuit to define a plurality of relatively high power handling capacitance circuits. A plurality of diodes are provided, and diode printed circuit boards mount the diodes and couple the diodes in electrical circuit to define a plurality of relatively high power handling diode circuit elements. A frame, and top and bottom plate-like members, and other joining structure join together the frame and the top and bottom plate-like members, and the capacitor printed circuit boards to form an enclosure wherein the top and bottom plate-like members and the capacitor printed circuit boards comprise four sides of a generally rectilinear, six-sided enclosure.

Abstract: A starting and operating circuit for a super compact fluorescent lamp includes ballast and discharge circuits for applying current to the filaments of the lamp and then apply starting pulses which enable the lamp to commence operation. The circuits include discharge devices and assure operation and proper starting of the lamp under low temperature as well as moderate temperature conditions.

Abstract: An attachment is provided for connection in fluorescent lamp circuits for reducing power consumption. The attachment is particularly designed for use with fluorescent lamp circuits having an encapsulated ballast including a transformer and capacitance. The attachment includes an isolation transformer with a capacitor and a resistor connected across the transformer, and an inductance connected in line with the primary of the ballast transformer with a resettable thermal switch connected to shut down the ballast transformer in response to high current overload conditions, and a surge voltage protection circuit connected through the thermal switch to shut down the ballast in response to a ballast power factor capacitor failure. The ballast and power reducer cooperate to produce a substantially square wave output resulting in increased system efficacy, reduced lamp lumen depreciation, and increased lamp life.