Abstract: A power-limited (Class-2/3) fluorescent lighting system suitable for use with suspended ceiling systems consists of the following principal components:a) power-line-operated power supplies, each power supply having a plurality of outputs, with each such output being a 30 kHz voltage limited in voltage/current/power magnitudes in such a way as to constitute a Class-2/3 circuit in accordance with the National Electrical Code;b) fluorescent lighting units, each such unit comprising one or more fluorescent lamps and a matching network operative to derive the requisite lamp operating voltages and currents from one of the Class-2/3 outputs of one of the power supplies; andc) for each lighting unit, a flexible wiring means to provide for easy plug-in connection with one of the individual outputs of said power supply.The individual lighting units and its wiring means can safely and easily be installed and/or removed by persons of but ordinary skills.

Abstract: A compact screw-in fluorescent lamp is mounted on an ordinary Edison-type screw-base. An inverter-type ballast is integrally included with the base, thereby making the fluorescent lamp capable of being screwed into an ordinary lamp socket and to be powered therefrom by ordinary power line voltage. The fluorescent lamp is folded and has a narrowed section of glass. The inverter-type ballast is powered via a voltage doubler and powers the fluorescent lamp via an tuned L-C circuit. Light output can be adjusted by way of an adjustment means functional to adjust the inverter frequency, thereby correspondingly to adjust the magnitude of the lamp current.

Abstract: A self-oscillating half-bridge inverter is powered from a power-line-operated rectifier means providing a DC voltage with a relatively high ripple content. The inverter is loaded by way of a series-tuned high-Q LC cirucit connected across this DC voltage. A pair of fluorescenet lamps is series-connected across the tank-capacitor of the LC circuit. Also connected across the DC voltage is an arrangement of three energy-storing capacitors charged in series and discharged in parallel; which arrangement results in the current drawn from the power line being of relatively high power factor and low harmonic distortion. Charging current for the energy-storing capacitors is derived from the high frequency current flowing through the LC circuit; and charging occurs only during periods near the peak of the power line voltage.

Abstract: A self-oscillating half-bridge inverter is powered from a power-line-operated DC voltage source by way of an EMI filter. The inverter is loaded by way of a series-tuned high-Q LC circuit connected across its output. A pair of fluorescent lamps is series-connected across the tank capacitor of the LC circuit. The inverter has two bipolar transistors, each driven by an associated saturable current transformer that provides for a transistor ON-time dependent upon the magnitude of an associated bias voltage. One of the transistors has a control arrangement connected in circuit with its associated saturable transformer and operative to control the magnitude of its associated bias voltage. As the magnitude of this bias voltage is controlled, the magnitude of the voltage across the tank-capacitor, as well as of the current available therefrom, is correspondingly controlled.

Abstract: An inverter is powered by a magnitude-modulated DC supply voltage derived by rectification from an ordinary 120Volt/60Hz electric utility power line. The inverter powers a low voltage (12 Volt) incandescent lamp with a magnitude-modulated high frequency (30 kHz) voltage. The magnitude modulation on the high frequency voltage is proportional to the magnitude modulation on the DC supply voltage.

Abstract: A lighting arrangement comprises:a) an array of plural pairs of series-connected fluorescent lamps, with each lamp pair: i) adapted to be powered from 30 kHz/240 Volt by way of a high-Q series-resonant L-C circuit, ii) receiving cathode heating by way of transformer connected with the 30 kHz/240 Volt, iii) connected in parallel with the capacitor of the L-C circuits and iv) connected in parallel with a circuit protection means operative to limit the magnitude of the voltage that can develop across the capacitor of the L-C circuit as a result of Q-multiplication, and --in response to a control signal, or in case the lamp pair fails to start within a reasonably short time--to place a short circuit across the capacitor;b) a frequency converter connected with a power line and operable to provide the 30 kHz/240 Volt; andc) programming means connected with each circuit protection means and operable: i) before providing 30 kHz/240 Volt to the array, to provide a signal to all circuit protection means, thereby placin

Abstract: A full-bridge transistor inverter is connected at its DC supply-side with an energy-storing capacitor. The inverter's output terminals are connected in series between a source of AC voltage and a load; which load may be an electric motor, a fluorescent lighting system, etc. By controllably switching the transistors of the inverter ON and OFF at some rate higher than, but basically synchronous with, the frequency of the AC voltage, effective control of the flow of power between the AC source and the load is achieved. DC voltage on the energy-storing capacitor is obtained from the AC source and established by way of the timing of the switching action of the inverter.

Abstract: A magnetic-type ballast powers two series-connected fluorescent lamps from a 277 Volt power line. Except when the lamps are loading the ballast, an electronic control circuit provides an intermittently interrupted short circuit across the two lamps: providing for socket voltages high enough to permit lamp ignition for a period of about 25 milli-seconds every two seconds or so, but keeping the average socket voltages low enough to satisfy safety requirements.When initially connecting power to the lamp-ballast combination, the control circuit enters its short circuit state and remains there for two seconds. Then, after two seconds, the control circuit switches into an open circuit, thereby permitting the voltage across the lamps to become high enough to cause lamp starting within a few milli-seconds. If the lamps fail to start, the electronic circuit reverts back to a short circuit within 25 milli-seconds.

Abstract: A fluorescent lamp operating system comprises:(i) a plurality of pairs of fluorescent lamps for providing luminous radiation, each pair of lamps being adapted to be powered from 30 kHz/120 Volt by way of a high-Q series-resonant L-C ballasting circuit;(ii) a relatively low-power frequency converter connected with the power line and operable to provide power for heating the cathodes in these fluorescent lamps, thereby conditioning the lamps for easy starting;(iii) a relatively high-power frequency converter also connected with a power line and operable to provide the 30 kHz/120 Volt required for operating the plurality of pairs of fluorescent lamps by way of the high-Q series-resonant L-C ballasting circuit; and(iv) delay means operable to prevent the 30 kHz/120 Volt provided by the high-power frequency converter from being applied to the fluorescent lamps until after power has been applied to heat the lamp cathodes for at least one second.

Abstract: At the lumen output levels of most ordinary household incandescent lamps, incandescent filaments designed for and operated at about 24 Volt RMS provide substantially higher luminous efficacy than filaments designed for and operated at 120 Volt RMS.A frequency converter, which is adapted to be plugged into and held by an ordinary household electric receptacle, coverts the 120 Volt/60 Hz received from the power line to an output of 120 Volt/30 kHz and provides this output at a receptacle adapted to receive and hold an ordinary power plug.The power plug of an ordinary table lamp is plugged into this frequency converter, thereby providing 120 Volt/30 kHz to its lamp socket instead of the normal 120 Volt/60 Hz.

Abstract: A power-line-operated ballast for two fluorescent lamps has a self-oscillating half-bridge inverter whose 30 kHz squarewave output voltage is switchably connected either with an auxiliary transformer and/or with a series-resonant L-C circuit. The lamps are series-connected across the tank capacitor of the L-C circuit; the lamps' cathodes are connected with individual outputs of the auxiliary transformer.When power is initially applied to the ballast, only the auxiliary transformer is connected with the inverter output, thereby providing heating power to the lamps' cathodes. After about 1.5 second, the L-C circuit is automatically connected with the inverter output, and the lamps then ignite in ordinary Rapid-Start manner. The auxiliary transformer is automatically disconnected at the time the L-C circuit is connected, thereby providing for extra high efficiency operation.In the event the lamps become disconnected or inoperative, the inverter will become disabled within about 15 milli-seconds.

Abstract: An inverter-type electronic fluorescent lamp ballast powers a fluorescent lamp with a sinusoidal current that is modified by insertion of a measured amount of properly phased third harmonic current, thereby attaining a lamp current crest factor that is substantially better than the 1.4 crest factor associated with a purely sinusoidally-shaped current.

Abstract: In an inverter-type power supply, a self-oscillating full-bridge inverter is powered by unfiltered full-wave-rectified 120 Volt/60 Hz power line voltage and controllably triggered into oscillation each half-cycle of the power line voltage by way of triggering two of the bridge's four transistors into conduction simultaneously. This is accomplished by way of discharging a charged-up capacitor by way of a Diac through a special trigger winding on each of two saturable current feedback transformers; each of which controls a pair of the bridge transistors.

Abstract: A fluorescent lamp ballast comprises a self-oscillating inverter with saturable transformer means in its positive feedback circuit. The saturation flux density of the magnetic material used in this saturable transformer means determines the frequency of inverter oscillation. A permanent magnet is rotatably mounted adjacent the saturable transformer means and is used by way of cross-magnetization to adjustably affect the saturation flux density of the magnetic material, thereby correspondingly to adjust the frequency of oscillation: the more cross-magnetizing flux provided to the magnetic material from the permanent magnet, the smaller the saturation flux density and the higher the frequency of oscillation.Current for the fluorescent lamp is attained from the inverter's squarewave voltage output by way of a series-excited parallel-loaded tuned L-C circuit, thereby providing for a lamp current of magnitude dependent upon the frequency of inverter oscillation.

Abstract: An electronic ballast provides a high-frequency current-limited voltage between a first socket terminal and a second socket terminal. These socket terminals are adapted to receive and hold a rapid-start fluorescent lamp. The first terminal has a relatively low-magnitude potential with respect to ground; the second terminal has a relatively high-magnitude potential with respect to ground. A person causing in direct or indirect contact with the second terminal is apt to receive a hazardous electric shock. A self-oscillating electronic inverter is operable to provide the high-frequency voltage. To provide an output, this inverter has to be triggered into oscillation. However, if no current flows from the first terminal, the inverter will automatically become disabled within 25 milli-seconds; whereafter it will not be re-triggered for about 1.5 seconds.

Abstract: In a power-line-operated electronic inverter-type ballast for a fluorescent lamp, a series-connected L-C circuit is connected directly across the otherwise unfiltered output of a full-wave rectifier that provides DC voltage to the inverter. This L-C circuit is tuned to series-resonance at 120 Hz, thereby effectively shorting-out the fundamental component of the 120 Hz ripple that otherwise would be present on the DC voltage. The result is a fairly well-filtered DC voltage obtained without the use of the conventional and often short-lived electrolytic capacitor. This particular method of reducing the amplitude of the ripple voltage results in a particularly high power factor in respect to the power drawn by the ballast from the power line.

Abstract: A number of power-line-operated high-frequency multi-output central power supplies are mounted at spaced-apart points on the permanent ceiling above a suspended ceiling. From each individual output of each such power supply, high frequency power is provided by way of flexible conductor means to a lighting fixture mounted nearby in the grid structure of the suspended ceiling below. Thus, high frequency power distribution is accomplished in a hub-and-spoke fashion by way of relatively short lengths of conductors--with each conductor carrying a relatively light current. Compared with the conventional bus-wire system of distributing high frequency power to a plurality of lighting fixtures, subject hub-and-spoke distribution system provides for substantially lower distribution losses and minimized radio frequency interference. Also, this hub-and-spoke system provides for more flexibility in terms of installing and positioning the fixtures in the suspended ceiling.

Abstract: In a power-line-operated electronic ballast for a gas discharge lamp, an inverter converts a DC supply voltage to a high frequency current-limited operating voltage for a fluorescent lamp. The DC voltage is obtained, at least in part, by forward inductive-discharge conversion of full-wave-rectified unfiltered power line voltage; which forward conversion is accomplished by high frequency switching of an energy-storing inductor; the switching being done by the very same inverter that provides the high frequency lamp operating voltage. As an overall result, power is drawn from the power line with a power factor higher than 98% and with a total harmonic distortion under 10%.

Abstract: A financial institution, such as a bank, issues numerous uniquely coded travelers checks to various individual entities in exchange for value received. The holder of each travelers check in entitled to receive a certain average rate of income from the dollar-value represented by that check; which average rate of income would generally be proportional to prevailing interest rate as well as to the dollar-value represented by the check. To avoid the relatively high transaction costs associated with periodic payments of a relatively modest income to the holder of each of numerous individual checks, a statistical method is used. By way of this statistical method, a relatively few of the numerous uniquely coded travelers checks are randomly chosen at the end of each of a continuous sequence of time periods, and all the income attributable to all the issued travelers checks for the associated time period is then paid to the holders of the relatively few travelers checks chosen for that time period.

Abstract: An improved 120 Volt/40 Watt incandescent light bulb is adapted to be used in an ordinary Edison-type lamp socket and provides nearly twice the effective Lumen-output as that of an ordinary 120 Volt light bulb of same power rating and same life expectancy.The improved light bulb comprises an electronic inverter-type voltage conditioner that provides a voltage of about 15 Volt RMS magnitude to the filament of a small Tungsten-Halogen lamp. This voltage conditioner is comprised within the bottom part of the light bulb and the Tungsten-Halogen lamp is mounted right above the power conditioner--all within an outer envelope.The improved light bulb has shape and size substantially the same as that of an ordinary household 120 Volt/40 Watt light bulb.Means are provided by which the Lumen output can be manually adjusted over a wide range.In one version, the outer envelope is removable and the small Tungsten-Halogen lamp is replaceable.