Abstract: A flashlight includes a source of power, a source of light, and switching circuitry connected with the source of power and the source of light. The source of light is a semiconductor diode capable of emitting white light when energized. The source of power may be a battery or a generator. The switching circuitry is operable between an on condition and an off condition. When the switching circuitry is in the off condition, it is effective to energize the semiconductor diode to provide light of a low intensity to facilitate locating the flashlight. When the switching circuitry is in the on condition, it is effective to energize the semiconductor diode to emit white light of an intensity sufficient to illuminate objects spaced more than six feet from the flashlight. The switching circuitry includes a transistor which is operated between conducting and nonconducting conditions by a flip/flop in response to manual actuation of a pushbutton.

Abstract: A discharge lamp lighting device includes an inverter circuit connected through a first impedance element across output ends of a rectifier rectifying an AC source power, a smoothing capacitor inserted through a discharging diode in a power supply path to the inverter circuit, and a series circuit of a second impedance element, discharge lamp and inductor and connected between an output end of the inverter circuit and one output end of the rectifier, wherein a path for charging the smoothing capacitor is formed through a switching element included in the inverter circuit, and the discharging diode.

Abstract: A self ballasted fluorescent lamp includes a rectifier which full wave rectifies AC power from a commercial source. A smoothing capacitor smoothes the rectified power. The smoothed, rectified power is provided to a high frequency generating circuit which drives the fluorescent lamp. The capacitance value C of the smoothing capacitor is selected such that W.gtoreq..alpha.C, where W (in watts)is the rated service power of the fluorescent lamp, and .alpha. is related to a ratio of W to C0 (in .mu.F). C0 is a capacitance value of the smoothing capacitor for which the 5th harmonic component of the input current is 61% of the fundamental component of the input current when the fluorescent lamp operates under fixed conditions. When the above condition is met, the percentage of harmonic content falls within IEC standards, etc.

Abstract: A low voltage illumination system, comprising a pair of terminals for connecting to a source of low frequency a.c. voltage, a frequency converter coupled to the source of a.c. voltage for converting the low frequency a.c. voltage to high frequency a.c. voltage, and a step down transformer coupled to an output of the frequency converter for converting to high frequency, low voltage a.c. A synchronous rectifier is coupled to a secondary of the step down transformer for converting the high frequency low voltage a.c. to a low magnitude nominally d.c. voltage, and a pair of conductors is connected to the low magnitude nominally d.c. voltage for connecting low voltage lamps thereto. Optionally, the step down transformer is of planar design and an integral overload protection circuit is provided responsive to a drop in output impedance across the conductors commensurate with an overload for interrupting power thereto.

Abstract: A compact fluorescent lamp and an electronic ballast therefor are mounted on a three-terminal base which can be fitted into a three-way-switched standard AC lamp socket, so as to be responsive to the three powered switch positions of the socket for generating three light output levels. The ballast includes an AC-to-DC conversion circuit which supplies a lamp driver including a DC-to-AC conversion circuit, an oscillatory circuit and a resonant circuit. In one embodiment the AC-to-DC conversion circuit includes a full bridge rectifier and a voltage doubler producing two operating voltage levels for the lamp driver and two frequency control voltage levels for the oscillator, the ballast generating three light output levels by using two operating voltages and two operating frequencies.

Abstract: A circuit arrangement for high-frequency operation of a discharge lamp comprises a low-frequency rectifier for generating a DC voltage (buffer voltage) across a first capacitor (C1) from a low-frequency supply voltage. A DC/AC converter generates a high-frequency AC voltage from the buffer voltage. A load branch is coupled to the DC/AC converter and is provided with coupling terminals for coupling the discharge lamp to the load branch. A high-frequency rectifier (HR) converts the high-frequency voltage generated by the DC/AC converter into a DC voltage and comprises a series arrangement of first and second diodes (D5, D6) which have the same orientation. A control circuit (CR) controls the power consumed by the discharge lamp to a level which is dependent on a control signal (Sg). The high-frequency rectifier further comprises a switching device and a further control circuit (CR1). The switching device shunts at least one of the diodes of a feedback unit.

Abstract: A system of igniting a gas discharge device having spaced electrodes immersed in a gas, at voltages below the required starter ignition voltage for cold cathodes. A square wave alternating voltage source of between about 75 kHz and 4 MHz is applied directly to the gas discharge device so that the voltage on the spaced electrodes reverses its polarity more rapidly than the pattern of electron and ion density in the gas can shift.

Abstract: A fluorescent lamp flashing circuit is comprised of a fluorescent lamp to which an alternating supply voltage source is connected through a series connected loading reactance device which provides current limiting. The heaters of the fluorescent lamp are independently fed. A switching device disconnects and reconnects the alternating supply voltage at a predetermined frequency rate which is determined by a control circuit which controls a switching device. When the switching device is closed, the fluorescent lamp is bypassed through a full wave rectifier bridge and the reactance device is connected in parallel with the supply voltage source and with a bleeding resistance to load the bridge and to form a resonant circuit to maintain the loading reactance device constant and permitting an energy exchange between the supply voltage source and the loading reactance device in a resonant mode thereby maintaining a sine wave form and minimizing loss.

Abstract: An apparatus for generating a microwave frequency energy includes a cathode for emitting electrons, a first grid for controlling and focusing the flow of electrons from the cathode, a choke structure for serving as a capacitor, wherein the cathode, the first grid and the choke structure define an input cavity functioning as a resonant circuit.

Abstract: An operating circuit for a gas discharge lamp includes a rectifier to be connected to an AC power line for generating positive and negative DC voltages, a first inverter connected to the rectifier for converting the DC voltages into a first substantially square wave AC signal, a series resonator for connecting the first inverter with a first lamp electrode, and a second inverter connected to the rectifier for converting the DC voltages into a second substantially square wave AC signal. The second inverter is to be connected to a second lamp electrode. The first and second substantially square wave AC signals have substantially equal fundamental frequencies and are out of phase.

Abstract: An emitting element driving circuit for driving an organic emitting element comprises at least one emitting element, and a rectifier directly connected in series to the emitting element. The driving circuit for driving an emitting element having a capacitor in parallel to an emission part in its electrical equivalent circuit capable of achieving a sufficient luminance even at a low voltage of the power supply during a high speed scanning driving.

Abstract: A non-dimmable electronic ballast has a unique inverter design which eliminates a large percentage of the required components, thereby simplifying and increasing the reliability of the ballast, while decreasing its costs. The ballast can provide power for either two or four fluorescent lamps and has additional safety and protection features which are not available in existing ballasts. A dimmable version is also disclosed with a dimming control at the ballast or which can operate a bank of ballasts with a central, remote dimming control or which can provide a variable output frequency to the ballasts to dim the lamps. There is very little distributed capacitance at the connections from the electronic ballast to the lamps. This feature eliminates points of resonances over the range of frequencies for dimming, thereby eliminating sudden changes in brightness as the frequency is varied.

Abstract: An apparatus (20) to control a high intensity discharge lamp (24) by generating fuzzy logic transfer functions (360, 362) with a software package (368). The fuzzy logic transfer functions (360, 362) are applied by a controller (210) for controlling the operation of the lamp (24). The first fuzzy logic transfer function (360) includes both of a lamp ignition membership function and a lamp steady state membership function. The second fuzzy logic transfer function (362) includes a first current error magnitude membership function and a second different current error magnitude membership function. Both of the first and second membership functions functionally related to both of the error current value and a PWM count change value. A current sense resistor (256) provides a signal indicative of lamp current to the controller (210). An internal real time clock (RTC) in the controller (210) measures the amount of time that the lamp (24) is operating and provides a real time signal for use in the controller (210).

Abstract: An electronic ballast to power a gas discharge load (FL1) operating from a low frequency AC voltage source (ACVS) equipped with a dimmer (DIM) and having variable voltage magnitude. The device comprising a primary resonant oscillator (RO1) exhibiting an inductive character of frequency dependent impedance as an auxiliary resonant inductance (La) interacting with an auxiliary resonant capacitance (Ca) coupled to a rectifier circuit (RB, VSD) which performs switching and rectifying functions developed by and synchronized with a pulsating current drawn from the rectifier circuit by the primary oscillator circuit (RO1) equipped with switching transistors (Q1, Q2) and adapted to deliver to the gas discharge load (FL1) high frequency signal to of a variable magnitude proportional to the variable magnitude of the voltage of the AC voltage source.

Abstract: For energizing remote lamp loads subjected to indeterminate transmission losses, a current regulating power supply is described which delivers a regulated current to the load using for example, a full wave rectifier supplying an unfiltered pulsating voltage to a switching regulator controlled by a feedback loop incorporating a current sensing resistor and pulse width modulator. The supply has a substantially unity power factor, a self-quenching characteristic in the presence of circuit interruptions, and can deliver regulated current to a variety of lamp types.

Abstract: A high frequency converter for driving a gas discharge lamp load is comprised of an input stage for receiving an AC input voltage and rectifying the input voltage to create a DC voltage source, an oscillating power inverter, an output stage connected to the power inverter, and a trigger circuit used to initiate oscillations in the power inverter. The trigger circuit further comprises a voltage ramp circuit. The output stage includes a transformer having a center tap and two capacitors of equal value connected from the tap to each end of the transformer. The capacitors and transformer form two resonant tanks. Also, an RF choke may be connected between the center tap and the source of DC voltage.

Abstract: A ballast for a gas discharge lamp comprises a resonant load circuit including a gas discharge lamp, and a resonant inductance and a resonant capacitance whose values determine the operating frequency of the remnant load circuit. A d.c.-to-a.c. converter circuit is coupled to the remnant load circuit to provide a.c. current to the remnant load circuit. The converter comprises at least one switch. A high voltage IC drives the at least one switch at a frequency determined at least in part by impedance between a timing input and a ground. A circuit for supplying a d.c. voltage to the d.c.-to-a.c. converter includes (i) a supply path for d.c. current; (ii) first and second return paths for d.c. current; and (iii) an arrangement to selectively make the first return path operable alone, the second path operable alone, and the first and second paths operable together. First and second impedances are coupled between the timing input and the first and second return paths, respectively.

Abstract: A bridge rectifier is connected with a 277Volt/60 Hz power line and provides full-wave-rectified unfiltered DC voltage to a series-combination of: i) an inductor, ii) a full bridge inverter switched in synchronism with the 60 Hz power line voltage, and iii) an electronic switching device. A fluorescent lamp is connected with the inverter's output and receives 60 Hz current of exceptionally low crest-factor, thereby operating at an exceptionally high efficacy. The electronic switching device is normally in a fully conductive state. However, it is controlled--by a photo sensor responsive to the light output of the fluorescent lamp--in such a manner that whenever the instantaneous light output exceeds a certain adjustably predetermined upper level, it switches into a non-conductive state where it remains until the instantaneous light output level diminishes to a certain adjustably predetermined lower level.

Abstract: A dynamic filter is interposed between the bridge rectifier and parallel-load resonant inverter of an electronic ballast. The dynamic filter circuit consists of two energy tanks and two energy transfer diodes and achieves power factor correction by performing input current shaping.

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 electronic starter for a fluorescent lamp comprises a power switch, controlled at its gate by a gate-control circuit and an auxiliary supply circuit that gives the necessary logic supply voltage to the gate-control circuit on a terminal of a capacitor. The gate-control circuit comprises a comparator with two voltage references to measure a duration of preheating of the lamp, the input of this comparator receiving the logic voltage given by the capacitor, the output of the comparator being used to command the closing or the opening of the switch. In one improvement, there is provided a preheating current measurement circuit to detect the optimum current for lighting up the lamp once the necessary preheating time has elapsed.

Abstract: A dimmable fluorescent lamp system embodiment of the present invention comprises a fluorescent lamp with filaments at each end that are continuously heated by independent secondary windings of a transformer. A resonating capacitor is connected in series with a resonating inductor and a pair of DC blocking capacitors are connected from each end of the fluorescent lamp to put it in parallel with the resonating capacitor. A control logic drives the primary winding with a pulse-width or frequency modulated square wave that is controlled by a feedback voltage derived from a pair of rectifiers and a dropping resistor in series with one of the DC blocking capacitors.

Abstract: Disclosed is a power-level selection circuit in combination with a lamp circuit including a fluorescent lamp having first and second cathodes with resistive-heating filaments each spaced at a respective end of a lamp tube; first and second power leads for respectively connecting the cathodes to an a.c. power source whose power can be selectively enabled and interrupted by a main power switch; and a ballast inductor in serial circuit with one of the power leads and including a plurality of filament-heating windings for supplying power to the cathodes. The power-level selection circuit is interposed between a first cathode and a filament-heating winding, and includes a power-receiving circuit coupled to the filament-heating winding to receive power therefrom. Further included is a filament-supply circuit for continuously supplying available power to the first cathode.

Abstract: A transformerless high-voltage generator circuit includes an amplifier and a feedback circuit connected together to form an oscillator. Due to the configuration of the feedback circuit, a high-voltage output is obtained at an intermediate point within the feedback circuit without the use of a transformer. The resulting circuit may be used in various applications, such as an electronic photoflash unit, in order to reduce the size, weight and cost of the finished product by eliminating the need for a transformer to obtain the desired high voltage.

Abstract: An improved fluorescent light ballast circuit extends the on/off life of a florescent lamp within a lighting circuit having a pair of series connected fluorescent lamps. The ballast circuit includes a DC pulse generation circuit, filtering and voltage regulation circuitry, a step-up voltage transformer, and a current altering circuit which alters the current within selected filaments within the lamps. The current altering circuit includes a diode and a coil winding which connect across a filament within one of the fluorescent lamps. The net effect of the current altering circuit is to increase the voltage supplied across the lamp connected to the current altering circuit so that the voltage levels across both lamps are balanced.

Abstract: In a switching inverter where switches are controlled so as to provide current through an inductor which is connected in series with other switches across a battery so as to power a capacitive load, such as an electroluminescent lamp, with higher voltage than the battery voltage, the other switches, which may be SCRs, provide a path for current which charges and discharges the lamp to provide the higher voltage as an alternating voltage across the load. These other switches are switched on in synchronism with pulses of current which are produced in the inductor by circuits providing capacitances at the triggering terminals of the other switches (control electrodes or gates in the case of SCRs). These circuits are connected to the inductor so that transients or spikes, occurring when the current through the conductor is switched, enable triggering current flow with respect to the capacitances. This triggering current flow automatically triggers the other switching devices.

Abstract: The invention relates to a circuit arrangement for igniting a high-pressure discharge lamp (L), provided with input terminals (C,D) for connection to a commutating supply source with a square-wave supply voltage; a pulse-generating circuit (IV) provided with a voltage-dependent breakdown element (3) and with a voltage-raising network (2) formed by a network of rectifiers and capacitors; a pulse transformer (1); and an electrical connection between a secondary winding (12) of the pulse transformer and lamp connection terminals (E,F). The voltage-raising network (2) is in addition provided with inductors means (21, 22). The result of this is that a strongly increased voltage is available across the breakdown element substantially instantaneously after each commutation of the commutating supply voltage.

Abstract: A fluorescent lamp ignition circuit of the type including a DC voltage stabilizer to process input voltage into a constant voltage by dropping or boosting, an inductance filter to receive output power supply from the DC voltage stabilizer and to remove surge from it, an oscillator having a transformer, which receives output power supply from the inductance filter and then provides a sin-wave output for igniting a fluorescent lamp, and a feedback circuit connected between the oscillator and the fluorescent lamp to provide a feedback signal to the DC voltage stabilizer, wherein the feedback circuit includes two shunt resistors, which connect the mid-point of the secondary side of the transformer of the oscillator to earth, and two diodes respectively connected between the shunt resistors and the DC voltage stabilizer to form a double-feedback loop.

Abstract: A circuit arrangement for igniting and operating a discharge lamp (La), provided withinput terminals (K1,K2) for connection to a DC voltage source,a commutator (COM) coupled to the input terminals and provided with terminals (K3,K4) for connecting the discharge lamp (La), for cornmutating a current through the discharge lamp (La),a branch A which is conducting in both directions at least for alternating current, of which branch a first end is connected to an input terminal (K2) and a further end is connected to the commutator (COM), and which branch comprises an inductive element L shunted by a branch B which comprises a unidirectional element (D),a branch C which connects a further input terminal to the commutator (COM), andan ignition circuit (S) for igniting the discharge lamp. According to the invention, the unidirectional element (D)is so included in the branch B that the branch B conducts a current at least immediately after ignition of the discharge lamp (La).

Abstract: A method of sensing the rms value of a phase chopped sinusoidal electrical waveform including combining an input signal representative of the waveform with an auxiliary signal in a combining circuit which produces a combining circuit output equal to whichever is the greater of the auxiliary signal and the modulus of the input signal, and averaging the combining circuit output over at least one half cycle of the waveform. The resulting output signal level is representative of the sensed rms value. By making the auxiliary signal equal to the product of a predetermined factor multiplied by a desired value of the output signal level, a feedback signal is produced to allow control of the rms voltage delivered to a load such as a lighting circuit.

Abstract: A light string system includes a plurality of LED's connected in parallel and a regulated power supply for providing a constant current and a constant voltage to the LED's. The light system may be used for decorative, signaling and a variety of other applications.

Abstract: A ballast circuit for a gas discharge lamp, of the type having a pair of resistively heated cathodes that are resistively heated both during a cathode pre-heat period prior to lamp turn-on, and during steady state lamp operation, is disclosed. The ballast circuit includes circuitry for providing, on a bus conductor, a d.c. bus voltage with respect to a ground, and a converter, responsive to the d.c. bus voltage, for supplying bidirectional current to a resonant load circuit. The resonant load circuit includes the gas discharge lamp, a resonant capacitor coupled between the lamp cathodes such that its voltage varies with lamp voltage, and a resonant inductor serially coupled to the resonant capacitor and cooperating therewith to set a magnitude, and resonant frequency, of the bidirectional lamp current. Circuitry is provided for powering the resistively heated lamp cathodes, to thereby heat the cathodes.

Abstract: A metal halide discharge lamp operated from a D.C. power source, which is suitable for an optical light source, has a quartz arc tube. Anode and cathode electrodes are disposed in the arc tube. The gap length between electrodes is so short that the metal halide discharge lamp functions as a point light source. The arc tube contains an inert gas, mercury and metal halide additives including metal bromine. By utilizing the catephoresis effects, the transformation of silica (SiO.sub.2) of the arc tube to cristobalite or the formation of an opaque substance on the arc tube is prevented. Atomic percent of bromine to halogen contained in the arc tube is about 60% to 90% and a wall load developed in the arc tube is substantially greater than 40 W/cm.sup.2.

Abstract: Disclosed is a lighting device to emit a light which substantially does not delay the latency of P300 wave in human ERP. Such a light hardly reduces human recognition and judgement when used in illumination. This renders the lighting device very useful in various illuminations directed to improve the efficiency and accuracy in visual tasks.

Abstract: A power line-operated electronic converter is adapted to deliver a relatively constant magnitude high frequency signal to a load (113) and is operable to draw a substantially sinusoidal current from the AC voltage source (101). The converter has DC input terminals (V+, V-) having a capacitor (108) connected therebetween, rectifying bridge (103) and boosting rectifiers (D5,D6) coupled to the DC input terminals, a resonant oscillator circuit coupled to the DC input terminals and to the transistor inverter (106) employing two integrated and synchronized resonant circuits having two resonant capacitors (114,112) and one common resonant inductor (110) wherein one circuit is used to operate the load and the other to provide boosted pulsating DC voltage to be naturally added and integrated with the rectified voltage of the AC voltage source.

Abstract: A portable flasher device is disclosed in which a pair of body members are connected together to form a housing which has bi-directional planar dimensions and an axial dimension, the planar dimensions being substantially larger than the axial dimensions to give the housing a substantially greater planar extent that the axial extent, and the bi-directional dimensions being such as to define a peripheral extent of the housing to make it suitable for holding the flasher device comfortably within the average human hand. The device includes a pair of battery compartments arranged at an angle to each other to define a space therebetween, with a circuit board and other operating components arranged within the space so as to reduce the thickness of the device to a minimum. A reflector and flasher lamp are mounted within a clear housing over the circuit board. The device is provided with a means for strapping it to a user's wrist or arm, or mounting it on a standard photographic tripod.

Abstract: Disclosed is a lighting device to emit a light which substantially does not elevate the ACTH level in human blood. Such a light hardly causes stresses when used in illumination. This renders the lighting device very useful in comfortable illuminated spaces for visual tasks.

Abstract: An electronic device for powering a gas discharge load (FL1) from a low frequency alternating voltage source (AVS). This device is drawing a current proportional to a voltage of the source (AVS) and is constituted by a resonant boosting circuit integrated into a power line voltage rectifier (BI,BRB) which performs boost switching and rectifying functions developed by and synchronized with a pulsating current drawn from the rectifier by a resonant oscillator circuit (RO1) equipped with a switching transistors (Q1,Q2) and adapted to energize the gas discharge load (FL1).

Abstract: A filling composition consisting essentially of about 20-75% by volume of xenon gas and about 15-80% by volume of nitrogen gas exhibits excellent luminous characteristics and an extended life expectancy but hardly causes arc discharge when enclosed in incandescent lamp. Incandescent lamps using the filling composition emit a light which is natural, appropriately high in color temperature, excellent in color rendering properties and gentle to the eye when operated at a voltage exceeding their rating but not exceeding 150% thereof.

Abstract: A cost-effective apparatus to improve the power factor of an AC line powered electronic transformer for powering gaseous discharge tubes uses an L-C filter link between a rectifier that provides DC voltage and an inverter for converting from DC to AC. The L-C filter link and the inverter function as a power factor correction stage, while at the same time converting DC voltage to AC voltage to drive gaseous discharge tubes.

Abstract: A ballast circuit for fluorescent lamp which comprises an additional D2 located just after the rectifier bridge D1 and before smoothing capacitors C5, C6. The diode D2 is matched to the value of a mylar capacitor C3 connected across the output of the rectifier bridge and the fluorescent lamp load whereby the fluorescent lamp draws current over substantially the whole of the supply voltage waveform to thereby improve the power factor and reduce the current harmonic distortion.

Abstract: The invention relates to a circuit arrangement suitable for high-frequency operation of a discharge lamp, provided withinput terminals (1, 2) for connection to a low-frequency supply voltage source,a rectifier circuit (G) coupled to the input terminals for rectifying a low-frequency supply voltage supplied by the low-frequency supply voltage source,a DC-AC converter,a branch (22) of which a first end is connected to a point of the DC-AC converter at which a high-frequency voltage is present during lamp operation and of which a further end is coupled to the rectifier circuit,the branch being conductive at least for alternating current in both directions, and the further end of the branch being connected to a first input terminal,where by the amount of interference caused by the circuit arrangement is considerably reduced, while the circuit arrangement can be realized with a comparatively small number of components.

Abstract: Disclosed is a lighting device to emit a light which substantially does not delay the latency of P100 wave in human VEP. Such a light hardly causes eyestrain when used in illumination. This renders the lighting device very useful in various illuminations directed to retaining healthy eyes.

Abstract: A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

Abstract: A power line-operated electronic converter is adapted to deliver a relatively constant magnitude high frequency signal to a load (113) and is operable to draw a substantially sinusoidal current from the AC voltage source (101). The converter has DC input terminals (B+, B-) having a capacitor (111) connected therebetween, first and second rectifier bridges (137, 138) coupled to the DC input terminals, a transistor inverter (131) coupled to the DC input terminals, a resonant oscillator circuit (135) coupled to the DC input terminals and to the transistor inverter employing a resonant inductor (117) and a resonant capacitor (114), and an input-output feedback implemented by coupling and modulation of a voltage developed across the resonant inductor to a voltage proportional to a difference of a voltage developed across DC input terminals and a voltage provided by a rectified AV voltage source.

Abstract: An operating circuit arrangement for a discharge lamp has a chopper circuit and an inverter circuit. The inverter circuit generates a high frequency voltage to start and operate the discharge lamp. The chopper circuit supplies a d.c. voltage to the inverter circuit. The circuit arrangement has a chopper control circuit and an inverter control circuit which are coupled to the chopper circuit so that the operation of each control circuit responds to the chopper circuit. In order to perform a soft starting operation in which the inverter circuit generates a given high frequency voltage to start and operate the discharge lamp prior to the generation of a given level of d.c. voltage generated by said chopper circuit, an inverter control circuit coupled to the inverter circuit is provided.

Abstract: A magnetic-electronic fluorescent lamp ballast is so arranged that the fluorescent lamp is powered simultaneously by two different currents; which two currents are supplied to the lamp by two separate parallel-connected current sources. One current is of 60 Hz frequency and is supplied directly from an ordinary 120 Volt/60 Hz power line by way of an ordinary magnetic reactor. The other current is of 30 kHz frequency and is derived from the power line by way of a frequency converter and is then supplied to the fluorescent lamp by way of a 30 kHz resonant circuit and a high-pass filter. The frequency converter is powered from the power line by way of a capacitive reactor, with the net result being that the power factor of the total power drawn from the power line is very high. The overall ballast is simple and provides for a relatively high efficacy.

Abstract: An electronic ballast is connected with the power line voltage of an ordinary electric utility power line and has an inverter functional to provide a high-frequency output voltage to a current-limiting circuit connected with a fluorescent lamp. The inverter includes a transistor whose collector-emitter is of trapezoidal waveform. Collector current flows through the transistor only during periods when the absolute magnitude of the transistor's collector-emitter voltage is very low compared with the maximum absolute magnitude of the collector-emitter voltage.

Abstract: An electrical device is provided for converting alternating current to direct current for an incandescent lightbulb circuit to extend the life of the bulb and reduce power consumption. The device provides a housing containing a diode rectifier adapted to be electrically connected to an alternating current source of supply and the incandescent lightbulb circuit. A resettable circuit breaker is employed to break the circuit when overloaded with an external resettable switch. The housing may further be provided with a low silhouette and a plug in order that the device may simply be plugged into an electrical wall receptacle. For ease of connection to the incandescent lightbulb circuit, an electrical receptacle may be provided on the exterior of the housing to receive a plug from the lightbulb circuit.

Abstract: In flashing light warning apparatus of a type having a voltage source (U), a main blocking transformer (HW), a flash tube (R), an ignition device (Z), a first and a third storage condenser (K1, K3), and an electrical switching device (S1), a switching path of the first electrical switching apparatus is arranged parallel to the first storage condenser, the third storage condenser and the ignition device are coupled to an auxiliary blocking transformer (ZW), and the first switching device can be switched by a control device (B). Such a flashing light warning apparatus can be produced in an uncomplicated, cost effective manner, to provide light energy which can be changed during operation to provide a day flash and at least one type of night flash. The night flash is at such a level that its output can be recognized from afar only by night vision apparatus.