Abstract: A constant-current regulator for high-powered airport lighting loops combined a ferroresonant transformer and a digital programmable logic device to provide a versatile, software-modifiable current control for power transfer throughout a range of about 30 kW to 50 kW with uniformly good power factor and low harmonics without switching winding taps, and without requiring oil cooling.

Abstract: A ballast for at least one electric incandescent lamp, having at least two switching elements (T1, T2) that are coupled to one another with the formation of a first tie point (VP1), a drive circuit (10) with at least one output for driving the switching elements (T1, T2) with the aid of a drive signal that has a pulse duty factor (d) and an operating frequency (fs), and with an input for a dimming signal (Ud), and a power transformer (Ü) whose primary side (L1) is coupled to the first tie point (VP1), it being possible to connect the electric incandescent lamp (LA1; LA2) to the secondary side (L2) thereof, the drive circuit (10) being designed to vary the pulse duty factor (d) and the operating frequency (fs) of the drive signal as a function of the dimming signal (Ud).

Abstract: A small size output transformer is capable of stablely producing sine wave oscillation at high efficiency. A drive circuit including a switching circuit is connected to DC power source input units and output transformer is connected to the drive circuit. At the drive circuit, the switching circuit is turned on and off based on a feedback signal of a primary side resonance voltage induced in an input side primary winding of the output transformer. The energizing direction of the DC power source to the output transformer is changed in direction by the on and off of the switching circuit, and the power source is applied as an AC signal to the input side primary winding of the output transformer. A phase detecting circuit detects the phase of the resonance wave form at the primary side of the output transformer sand outputs the phase signal.

Abstract: A reliable and efficient circuit for lighting a discharge lamp is described. An inverter accepts a direct current supply voltage and outputs an alternating current lamp voltage to drive the discharge lamp at a relatively high frequency. In one embodiment, the inverter includes semiconductor switches in a full-bridge configuration, a transformer feedback circuit to control the semiconductor switches, and a series L-C resonant circuit. In one embodiment, the inverter includes semiconductor switches in a half-bridge configuration, a transformer feedback circuit to control the semiconductor switches, and a series L-C resonant circuit. The inverter can drive multiple discharge lamps in a parallel configuration. A bypass circuit can also be coupled across a cathode of the discharge lamp to extend the life of the discharge lamp. The bypass circuit activates when a lamp cathode wears out.

Abstract: A constant-current regulator for high-powered airport lighting loops combined a ferroresonant transformer and a digital programmable logic device to provide a versatile, software-modifiable current control for power transfer throughout a range of about 30 kW to 50 kW with uniformly good power factor and low harmonics without switching winding taps, and without requiring oil cooling.

Abstract: A method for converting a higher voltage recessed light fixture such as a fixture having an Edison base to a second lower voltage halogen fixture, and a retrofitted recessed light fixture for providing a halogen bulb light source. The light fixture includes an open-end housing, a higher voltage connection base disposed within the housing, and a transformer with a base connector element complimentary to the connection base and connected into the base. The transformer provides halogen bulb voltage and accepts a halogen bulb. An end enclosure covers the open end of the housing except for an opening there through which exposes the illumination face of the halogen bulb. Connecting the halogen bulb to the transformer and applying electric power through the base results in illumination delivery from the halogen bulb in a modernistically appearing light fixture.

Abstract: A push-pull inverter is supplied from an inductively current-limited DC voltage source by way of a center-tap on a transformer having significant inductance. This transformer inductance is parallel-coupled with a capacitance means. The inverter is made to self-oscillate through positive feedback provided by way of a saturable current transformer. The inverter frequency is determined by the saturation time of this current transformer, which saturation time is designed to be somewhat longer than the half-cycle period of the natural resonance frequency of the transformer inductance combined with the capacitance means. By controlling the length of this saturation time, the magnitude of the current provided to the fluorescent lamp is controlled, thereby permitting control of the light output in response to changes in the magnitude of the power line voltage.

Abstract: A method for reducing the harmonics created by rapid-start fluorescent lamp stabilizer balance systems is accomplished by increasing the number of turns of the secondary winding of the transformer so as to decrease the secondary current to approximately 40 to 90 percent of the rated lamp current. This method increases the impedance and reduces the secondary current between 40 and 90 percent of the rated lamp current. While the absolute value of the illuminous intensity is lowered by the reduction in the secondary current, the lamp maintains a uniform brightness of illumination. This method decreases the distortion in the primary wave form which decreases the distortion effect on sensitive electronic systems which may be connected to the same electrical power source or may be in the area near the stabilizer.

Abstract: A power supply for high voltage, low current gas discharge tubes such as neon, argon, and mercury vapor. A free running, flyback oscillator, converts D.C. voltage energy into radio frequency energy by means of a compact, ferrite transformer and associated circuitry. The primary winding is tuned by a resonant capacitor and driven by a power transistor. A high voltage, centertapped winding of a ferrite transformer drives the gas tube load directly. A feedback winding arranged across the transistor base and emitter junction sustains oscillation and controls the drive level of the transistor by means of a regulating circuit which controls the amplitude of the current. Oscillator starting is achieved by means of an on-off switch which supplies a single starting pulse to the power transistor or by means of a time delayed starting pulse.

Abstract: A method for reducing the harmonics created by rapid-start fluorescent lamp stabilizer balance systems is accomplished by increasing the number of turns of the secondary winding of the transformer so as to decrease the secondary current to approximately 40 to 90 percent of the rated lamp current. This method increases the impedance and reduces the secondary current between 40 and 90 percent of the rated lamp current. While the absolute value of the illuminous intensity is lowered by the reduction in the secondary current, the lamp maintains a uniform brightness of illumination. This method decreases the distortion in the primary wave form which decreases the distortion effect on sensitive electronic systems which may be connected to the same electrical power source or may be in the area near the stabilizer.

Abstract: A circuit arrangement for limiting the current at make for a transformer wherein, in order to avoid the current peak at make when switching a transformer on, resistors are connected between operating voltage and the primary winding of the transformer. A test winding at the secondary side of the transformer is connected via a rectifier to the supply input of a contactor, so that the switches of the contactor close after the transformer is turned on and the resistors therefore no longer lie between operating voltage of the primary winding. PTC-resistors connected in series with the resistors assure that the resistors are not overloaded by the high-operating current of the transformer if the switches do not switch.

Abstract: A circuit that senses a current signal in a secondary winding of a transformer by monitoring a current signal in a primary winding of the transformer. The monitored current signal contains an effective current component and a magnetization current component. The magnitude of the effective current signal is related to the magnitude of the current signal in the secondary winding by the turns ratio of the transformer. The magnetization current signal produces flux in the transformer core and does not contribute to producing current in the secondary winding of the transformer. In addition, the magnetization current is 90 degrees out of phase with the effective current signal in the primary winding. The effective current signal in the primary winding is in phase with the voltage signal applied to the primary winding. The invention integrates the monitored current signal over 0 degrees to 180 degrees of the effective current signal waveform.

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: Constant-current regulators are required, for example, in systems for airfield lighting and have units for nominal-value presetting and actual-value detection as well as for actual value/nominal value comparison. According to the present invention, a constant-current regulator having a step-up transformer is designed in such a manner that the primary of the step-up transformer is assigned a unit for selection of a basic voltage, and in such a manner that a switch-mode regulator module supplies a power which is applied to the basic voltage.

Abstract: A series-fed light monitoring system, used for example for runway lights at airports, and fed by a low-frequency feeding current, comprises at least one series loop having one or more loading points connected in series in the form of fittings with lamps or the like, each loading point being connected to the loop via transformer coupling comprising in series a high-frequency transformer, a switch and a choke. The switch and the choke are connected in series in the series loop and the high-frequency transformer is connected on the primary side to the series loop and on the secondary side to the loading point. The choke has an inductance so as not to hinder a low-frequency feeding current in the loop but provide high impedance at the switching frequency.

Abstract: A power supply for high voltage, low current gas discharge tubes such as neon, argon, and mercury vapor. A free running, flyback oscillator, converts D.C. voltage energy into radio frequency energy by means of a compact, ferrite transformer and associated circuitry. The primary winding is tuned by a resonant capacitor and driven by a power transistor. A high voltage, centertapped winding of a ferrite transformer drives the gas tube load directly. A feedback winding arranged across the transistor base and emitter junction sustains oscillation and controls the drive level of the transistor by means of a regulating circuit which controls the amplitude of the current. Oscillator starting is achieved by means of an on-off switch which supplies a single starting pulse to the power transistor or by means of a time delayed starting pulse.

Abstract: A system for providing a constant current to airport or airfield signs is disclosed. The system receives input currents of varying amperages which also supply, and allow dimming of, runway or taxiway lights. According to various exemplary embodiments of the present invention, a high power factor is achieved which provides greater cost efficient operation of the signs.

Abstract: A universal electronic ballast system (10) is provided for actuating at least one gas discharge lamp (1900) having any one of a plurality of predetermined wattage ratings. Electronic ballast system (10) includes a filter circuit coupled to an AC power mains (100, 110) for substantially suppressing spurious signals passing into or from the power source. The filter circuit is coupled to a regulated switching power supply circuit (14) which generates a regulated boost voltage and draws a substantially constant in phase sinusoidal load current from the power source supplied to a switching circuit (16) which generates a regulated pulsating current at a predetermined frequency. Responsive to the regulated pulsating current a high voltage is induced in the primary windings (1710 and 1680) of induction transformer (T3). The high voltage is coupled to gas discharge lamp (1900) by means of the magnetic coupling betwen primary winding (1730) and secondary winding (1765) of the output transformer (T2).

Abstract: A non-inverting gallium arsenide depletion mode latch circuit is responsive to high and low input data, and to clock pulses from a clock having high and low pulses for loading data and for translating data from the input to the output in a single gate delay. The circuit includes a pair of pull-up FETs having their conduction paths connected in parallel with an output node in circuit with the FETs for output data. A positive feedback path is enabled from one of the FETs for reinforcing the data at the output node. The one FET enables the feedback path during clock pulses in the low direction, while the other FET applies data to the node during high clock pulses. Data input FETs enable and disable the other FET in accordance with the input data and selective clock pulses, while a clock pulse input FET enables and disables the one FET in accordance with the clock pulses.

Abstract: This invention relates to fluorescent lamp controllers and dimming controls for use therewith and more particularly to the provision of a dimming control which provides protective isolation between input terminals and lamp energizing circuitry and which facilitates accurate and safe control of light intensity over a wide range. The invention provides dimming controls which are efficient and highly reliable and are readily and economically available.

Abstract: A power supply for high voltage, low current gas discharge tubes such as neon, argon, and mercury vapor. A free running, flyback oscillator, converts D.C. voltage energy into radio frequency energy by means of a compact, ferrite transformer and associated circuitry. The primary winding is tuned by a resonant capacitor and driven by a power transistor. A high voltage, centertapped winding of a ferrite transformer drives the gas tube load directly. A feedback winding arranged across the transistor base and emitter junction sustains oscillation and controls the drive level of the transistor by means of a regulating circuit which controls the amplitude of the current. Oscillator starting is achieved by means of an on-off switch which supplies a single starting pulse to the power transitor or by means of a time delayed starting pulse.

Abstract: A power supply for high voltage, low current gas discharge tubes such as neon, argon, and mercury vapor. A free running, flyback oscillator, converts D.C. voltage energy into radio frequency energy by means of a compact, ferrite transformer and associated circuitry. The primary winding is tuned by a resonant capacitor and driven by a power transistor. A high voltage, centertapped winding of a ferrite transformer drives the gas tube load directly. A feedback winding arranged across the transistor base and emitter junction sustains oscillation and controls the drive level of the transistor by means of a regulating circuit which controls the amplitude of the current. Oscillator starting is achieved by means of an on-off switch which supplies a single starting pulse to the power transistor or by means of a time delayed starting pulse.

Abstract: A power supply for high voltage, low current gas discharge tubes such as neon, argon, and mercury vapor. Free running, flyback oscillator, converts D.C. voltage energy into radio frequency energy by means of a compact, ferrite transformer and associated circuitry. The primary winding is tuned by a resonant capacitor and driven by a power transistor. A high voltage, centertapped winding of a ferrite transformer drives the gas tube load directly. A feedback winding arranged across the transistor base and emitter junction sustains oscillation and controls the drive level of the transistor by means of a regulating circuit which controls the amplitude of the current. Oscillator starting is achieved by means of an on-off switch which supplies a single starting pulse to the power transistor or by means of a time delayed starting pulse.

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 fluorescent lamp controller uses a dimmer circuit having an isolation transformer. The controller applies a high frequency current to the primary winding of the transformer. The secondary winding is coupled to a control input via loading circuitry. A detector circuit supplies a signal to the lamp controller indicative of the resultant loading of the transformer to control lamp intensity.

Abstract: The ignitor is a high voltage power supply for intermittent operation used to ignite HMI (Hydrargyrum Medium Arc Iodide), Xenon and mercury arc lamps of the type typically used in motion pictures, video applications, theater and television. The ignitor inputs through a rectifier circuit and the rectified current drives the primary coil of the first transformer of two ganged transformers. The primary coil is driven into saturation, at which point a pulse-width modulated controller senses that the saturation current has been reached in the primary, and opens a FET which acts as a switch in series with the primary, collapsing the field around the primary to induce an energy surge into the secondary, which results, after further conditioning and transforming, in the production of a high voltage (30 kv-50 kv) arc-jumping current to ignite the arc lamp to which it is connected.

Abstract: The present invention relates to an improved line regulated ballast circuit for use in controlling varied lighting applications such as, for example, neon signs and fluorescent tubes. The inventive circuit, when used in neon lighting applications, may include a function generator which controls the lighting of the neon tube in a manner allowing the tube to slowly write from one end to the other in alternating current. The function generator also allows such functions as flashing, modulation, steady state operation and steady state operation with dimming function. In a further aspect, the inventive circuit with transformers connected in parallel with one another, may be utilized to simultaneously control a plurality of neon tubes, fluorescent tubes, or both concurerntly. In this application, each of the transformers may be provided with a shunting mechanism designed to render the output current thereof infinitely adjustable.

Abstract: A power current regulator, in particular for airport lighting, includes transformers in series with intermediate taps on their secondary windings staged a various different numerical weights. In each case, one of said taps is selected by a latch memory (MV) preceded by an up/down counter (CD). These circuits are actuated by a control circuit as a function of the current detected by a current transformer (TIC) connected in series with the load.

Abstract: A low cost circuit addition in the form of a capacitor of suitable value provides effective starting and operation of rapid start, preheat, and instant start fluorescent type gas discharge lamps along with their standard A.C. operated ballast transformer auxiliary devices at reduced power levels to achieve energy conservation with a concomitant reduction in light output and can usefully employed in illuminated areas where a reduction in lighting level would not effect the utility of that particular area. The capacitor is connected in series with the ballast primary winding and is of such value as to cause ferro-resonance to occur in the ballast transformer primary circuit, thereby providing a voltage magnification effect to aid the lamp starting, or ignition, process i.e., during the time interval between circuit energization and production of a stable arc, and to thereafter operation of the lamp with reduced arc current.

Abstract: To provide a reliable start for cadmium and zinc lamps and reduce baseline noise in an absorbance monitor, voltage pulses are applied to the primary of a transformer followed by shutoff of the primary current which discharges the energy stored in the magnetizing inductance of the transformer as three thousand volt peaks in its secondary in a series of timed steps. At the end of the timed period, the system shuts down unless it has approached operating frequency. The frequency is controlled by the amount of current passing through a gas discharge lamp in circuit with the transformer secondary and the frequency controls the amplitude of the voltage spikes. After warm-up, blanking pulses prevent optical noise from electrical-path-change oscillations within the tube. In one embodiment, a constant current source controls the current and in another, an operating current and frequency are established by the transformer leakage inductance and lamp characteristics in the circuit.

Abstract: A high frequency gas discharge lamp dimming ballast with good line power factor is disclosed. The unit is controlled by a current sensing loop which senses control switch current rather than lamp current and employs simple circuitry with sufficiently rapid control response necessary to maintain high line power factor and stable lamp operating characteristics over a very wide range of light output. An isolated output transformer provides protection against most common miswire conditions and accurately regulates lamp energy over a wide range of input and lamp arc voltage conditions. A pulse width modulated control input provides an isolated control input for easier wiring and reduces the susceptibility of the control to noise interference.

Abstract: A fluorescent light source and power supply adapted therefore in which a set of three D.C. mercury discharge paths are provided adjacent each other in a single tubular envelope. A cathode is provided at the base end of each path and a single anode at the other end. The three discharge paths are isolated longitudially extended semi-circular glass insulator partitions. The power supply provides D.C. voltage across the anode and cathodes and a switching circuit which transfers energy from a transformer during portions of the switching cycle to efficiently power the tube.

Abstract: To provide a reliable start for cadmium and zinc lamps and reduce baseline noise in an absorbance monitor, voltage pulses are applied to the primary of a transformer followed by shutoff of the primary current which discharges the energy stored in the magnetizing inductance of the transformer as three thousand volt peaks in its secondary in a series of timed steps. At the end of the timed period, the system shuts down unless it has approached operating frequency. The frequency is controlled by the amount of current passing through a gas discharge lamp in circuit with the transformer secondary and the frequency controls the amplitude of the voltage spikes. After warm-up, blanking pulses prevent optical noise from electrical-path-change oscillations within the tube. In one embodiment, a constant current source controls the current and in another, an operating current and frequency are established by the transformer leakage inductance and lamp characteristics in the circuit.

Abstract: An electronic ballast-inverter circuit for powering one or more fluorescent lamps or the like includes two identical circuits operating at different DC offsets, each circuit including a tank circuit composed of a primary winding of the power transformer and a capacitor such that each tank circuit resonates at the same frequency, and including a switching transistor connected to each tank circuit. These two transistors are operative on alternate half cycles of the sine wave generated by the inverter, so as to obtain the push-pull operation needed by the inverter. Each circuit includes a base drive current source for each transistor that is controlled by the polarity of an additional primary winding of the power transformer. For improved efficiency, the circuit is designed to be operable from an unsmoothed DC voltage source.

Abstract: A system operating in combination with a gas discharge lamp, such as a fluorescent lamp having electrodes therein, to effect ignition in a cold state without an ignition delay. Applied across the electrodes through a current-limiting coil is a voltage derived from a standard alternating-current supply. The supply voltage is also applied through an ignition switch to a starter coil inductively coupled to the current limiting coil to define therewith a step-up transformer, such that when this switch is closed, a high ignition voltage is imposed on the electrodes to produce an arc-discharge which heats up the electrodes. The resultant electron emission from the electrodes makes it possible to re-open the ignition switch after a brief interval, the lamp thereafter continuing to operate on the relatively low supply voltage.

Abstract: A power system comprising a high voltage, low power transformer that utilizes self-resonance parameters and pulse control techniques for efficiently firing a gas discharge lamp of the type commonly used to form a luminous advertising display. The transformer is fabricated from a material, such that the transformer will have a characteristic self-resonating frequency. The transformer is driven by Direct Current pulses from a source of supply thereof. The widths of the current pulses are controlled so as not to exceed one fourth the wavelength of the self-resonating frequency of the transformer. Performance is optimized when the repetition rate of the current pulses is directly controlled according to the self-resonating frequency of the transformer.

Abstract: A filament heating apparatus for an X-ray tube having an isolation transformer through which a control signal is digitally transmitted regulates the filament current to be constantly stable. The control signal is comprised of one of a reference signal based upon the characteristics of the X-ray tube and a component of the filament current.

Abstract: A capacitor discharge ignition system for a jet engine which has a relatively high power factor at the transformer input without exceeding the one ampere current rating required in jet ignition systems at the desired power level. A specially designed power transformer (10 ) has a capacitor (3) connected across closely coupled primary and tertiary windings (11 and 12).

Abstract: A regulated power supply for a laser or gas discharge lamp employs a variable duty cycle oscillator to control the output voltage level. Output current to the laser or lamp load is maintained at a constant value by a feedback loop that controls the oscillator duty cycle. The output current is sensed by a novel circuit which employs a voltage regulator in series with the current return path. A change in output current causes a concomitant change in voltage across a resistor divider that shunts the voltage regulator. The voltage from this divider is a feedback signal that is supplied to a duty cycle modulator which controls the oscillator duty cycle.Another feedback signal is derived in delayed response to voltage output in excess of a certain high value. This feedback signal, which occurs, e.g.

Abstract: An electrical power supply arranged to provide an alternating voltage output, which includes a pair of transductors or saturable reactors connected in phase opposition in series to the output and provided with means for supplying them with a constant d.c. control current so as to operate in the forced magnetization mode thereby providing a constant current source with a high output impedance, the output current being set by the control current.