Abstract: A light-emitting device includes a power module, a first light-emitting module, a second light-emitting module, a third light-emitting module, and a control module. The power module is configured to rectify an AC voltage for providing a periodic driving voltage. The first, second, third light-emitting modules are connected in series. The control module is configured to make the first, second, third light-emitting modules being driven by the driving voltage in response to different driving stages in a cycle period of a driving voltage. An average-diode-junction-area of the first light-emitting module is different from an average-diode-junction-area of the second light-emitting module or an average-diode-junction-area of the third light-emitting module.

Abstract: A device for improving power efficiency for power factor correction is disclosed, which comprises a primary load, a power module, a power factor correction module, a current source module, and a secondary load. The power module rectifies an alternating current (AC) voltage to a pulsating direct current (DC) voltage. The power factor correction module filters the pulsating direct current (DC) voltage to a driving voltage. The current source module is connected to the power module, the primary load and a side of the power factor correction module that drives the primary load with the driving voltage. The secondary load is connected to another side of the power factor correction module, and is driven by the power factor correction module.

Abstract: Devices comprise first and second terminals (1,2) connected to first load circuits (21) comprising first light emitting diodes, and third and fourth terminals (3, 4) connected to second load circuits (22) comprising second light emitting diodes, first connections (11) that interconnect the first and third terminals (1, 3), second connections (12) that interconnect the second and fourth terminals (2, 4), at least one of the first and second connections (11, 12) being a power dissipating connection, at least one of the first and second load circuits (21, 22) being adapted to receive first power from a source (31) via the first and second connections (11, 12), and capacitors (41) coupled in parallel to the second load circuits (22) for storing energy received via elements (42) with current-direction-dependencies and for providing second power to at least the second load circuit (22).

Abstract: A PFC LED driver capable of reducing current ripple, comprising: a current source unit, having a control terminal coupled to a control voltage, which is a ratio of a full-wave rectified line input voltage, a first channel terminal coupled to a power line, and a second channel terminal used to generate an output current according to the control voltage; and at least one LED load unit, being in series with the current source unit, wherein each of the at least one LED load unit comprises: a first load, including a first parallel combination of an LED module and a capacitor, wherein the LED module has at least one light emitting diode; a diode, being in a first series combination with the first load; and a switch, being in a second parallel combination with the second series combination.

Abstract: A PFC LED driver capable of reducing current ripple, comprising: a current source unit, having a control terminal coupled to a control voltage, which is a ratio of a full-wave rectified line input voltage, a first channel terminal coupled to a power line, and a second channel terminal used to generate an output current according to the control voltage; and at least one LED load unit, being in series with the current source unit, wherein each of the at least one LED load unit comprises: a first load, including a first parallel combination of an LED module and a capacitor, wherein the LED module has at least one light emitting diode; a diode, being in a first series combination with the first load; and a switch, being in a second parallel combination with the second series combination.

Abstract: According to one embodiment, an LED lighting circuit includes a lighting circuit provided between an external power supply and LED elements and a control circuit that controls the lighting circuit. The lighting circuit includes an electrolytic capacitor, the capacitance of which decreases to be lower than a rated value or the impedance of which increases to be higher than a rated value at temperature equal to or lower than ?20° C. The control circuit performs an initial lighting operation under a temperature environment equal to or lower than ?20° C.

Abstract: A pixel circuit related to an organic light-emitting diode (OLED) is provided. When signals having appropriate operating waveforms are supplied, the circuit configuration (6T1C) of the pixel circuit keeps a current flowing through an OLED unchanged when the Vth shift of the TFT for driving the OLED changes and eases the impact of a power supply voltage Vdd on the current. Thereby, the luminance uniformity of an OLED display adopting the OLED pixel circuit is greatly improved.

Abstract: A light-emitting diode driver circuit includes: a first-rectifier circuit to output a first-rectified voltage; a transformer including primary and secondary coils and an auxiliary coil inductively coupled to the primary or secondary coils, the primary coil being applied with the first-rectified voltage; a transistor connected in series to the primary coil; a second-rectifier circuit to output a second-rectified voltage obtained by rectifying a voltage generated in the auxiliary coil; a capacitor to be charged with the second-rectified voltage; and a control circuit to control on and off of the transistor based on a charging voltage of the capacitor so that the charging voltage becomes equal to a predetermined voltage, the secondary coil outputting a voltage that varies with a frequency corresponding to a frequency of the first-rectified voltage and that corresponds to a turns ratio between the primary and secondary coils, as a voltage for driving a light-emitting diode.

Abstract: Improved circuits minimize, or eliminate, energy losses in LED lighting. Diodes and a capacitor reduce or eliminate blinking and create smooth and continuous infinitely variable dimming. The components supply power to each LED during the half of the AC cycle where it would normally be turned off. Added diodes allow an added capacitor to charge during the half cycle that the original diode is turned on, but does not allow the other half cycle to discharge the added capacitor. When the added capacitor is charged enough to turn on the original diode, it stays on throughout the AC cycle. Zener diodes protect the LEDs from voltage surge's/spikes by shunting current around LEDs when the voltage exceeds the Zener diode's breakdown voltage. A microprocessor controller with MOSFETs provides an ultra efficient embodiment with near zero power dissipation.

Abstract: A voltage converter for use in a backlight module stores energy of an input voltage using an inductor and outputs a plurality of output voltages accordingly. The charging path of the inductor is controlled according to the first output voltage so that the first output voltage can be stabilized. The discharging paths from the inductor to other output voltages are controlled according to the differences between other output voltages and the first output voltage so that other output voltages can also be stabilized.

Abstract: A switch mode power supply (SMPS) system includes a rectifying circuit for coupling to an AC input voltage and a transformer having a primary winding for coupling to the rectifying circuit and a secondary winding coupled to the primary winding. The system also has a power switch coupled to the primary winding and a control circuit coupled to the power switch. The control circuit is configured to control current flow in the primary winding such that an envelop waveform formed by peak points of current pulses are in phase with the magnitude of the AC input voltage. Moreover, the SMPS system is configured to provide a constant average output current.

Abstract: Disclosed is a liquid crystal display panel which includes a switching circuit for converting an input voltage into an alternating current (AC) voltage, a transformer for boosting the AC voltage generated from the switching circuit, and a bypass capacitor part connected in parallel between an output terminal of the switching circuit and the transformer.

Abstract: The invention relates to light sources having an ultra-low active-energy consumption. The LED lamp of the present invention includes a voltage down-converter (1) in the form of two capacitors (2, 3), one of which is a power bleed capacitor, and at least one pair of light diodes connected back-to-back and in parallel (5, 6). According to the invention, in order to reduce the reactive current in the supply circuit, an induction (8) is coupled in series with the light diodes (5, 6) and defines an electric oscillating circuit (9) together with the power bleed capacitor (3) according to one variant of the invention, and together with the output capacitor (11) and the light diodes (5, 6) according to another variant.

Abstract: A charging circuit has a battery 12, switching element 14, and resistor 16 for current detection arranged on the primary side of transformer 10. Diode 18 and capacitor 20 for storing electric power are arranged on the secondary side of transformer 10. In a normal state, the ON/OFF states of switching element 14 are repeated corresponding to output signals U1, U2 of two comparators 28, 30. However, if switching element 14 stays on or off longer than a prescribed period of time for some reason, the status of switching 14 will be switched forcibly by an auxiliary sequence of the logic parts in control logic 42.

Abstract: The electronic reactor for discharge lamps (L) comprises a bridge rectifier (5) connected to an alternating voltage source (3); a half-bridge with two controlled switching means (11, 13) made alternately conducting to connect the said lamp (L) and the said bridge rectifier (5); a resonant load circuit (17) connected to the said half-bridge (11, 13); and a smoothing capacitor (29) connected in parallel with the half-bridge (11, 13). An auxiliary resonant circuit (33) is provided to reduce the crest factor and correct the power factor between the output (19) of the half-bridge (11, 13) and the positive pole (5A) of the bridge rectifier (5).

Abstract: Circuitry is disclosed for operating with no stroboscopic effects at least three fluorescent lamps connected to a single source of single phase alternating voltage. In order to suppress the stroboscopic effects, the first lamp circuit (1) is connected in the usual way to both conductors (S;Mp) of the source of single phase alternating voltage; a series oscillating circuit (4) composed of an inductive resistor (L) and a capacitor(C) is arranged in parallel to the first lamp circuit; the second lamp circuit (2) is connected between a conductor (S) of the source of single phase alternating voltage the point of connection (Vp) between the inductive resistor (L) and the capacitor of the series oscillating circuit (4); and the third lamp circuit (3) is connected between said point of connection (Vp) and the other conductor (Mp) of the source of single phase voltage.

Abstract: To eliminate the necessity for a saturated or air gap inductance to provide feedback circuit for a self-exciting oscillator including two active electronic switches (T1, T2) , for example MOSFETs, an auxiliary winding (HW1, HW2, . . . HW11) is inductively coupled to the resonance inductance (L2) present in the circuit for the discharge lamp (LP) anyway; and a pulse shaping - phase shifting network (R3, C3; R4, C4 . . . ) , devoid of inherent resonance, coupling the auxiliary winding to the active switching elements. The pulse shaping - phase shifting network is formed of a one or multiple-stage RC low-pass circuit, connected serially between the auxiliary winding and the control input, for example the gate, of the active switching element. The RC network can be constructed with variable elements, for example including PTC resistors, a varistor or the like, and may include a current source, protective circuits to protect against voltage peaks including Zener diodes.

Abstract: A power regulating ballast for gaseous discharge lamps operated from a source of high-frequency power incorporates a method in an apparatus which utilizes a distributed capacitance in combination with an inductor and includes a current feedback derived from charges in the current flow through the lamp.

Abstract: A ballast circuit system provides for efficient starting and operation of high voltage discharge lamps using a common 120 volt AC power source. As a result of this improved ballast circuit system, the necessary high voltage is generated from a normal 120 volt AC in such a way that there is low power loss. The system efficiency allows for use of plastic fixtures and small size packaging of the discharge lamp.

Abstract: High frequency components of input digital speech samples are emphasized by a preemphasis filter (11). From the preemphasized samples a spectral parameter (a.sub.i) is derived at frame intervals. The input digital samples are weighted by a weighting filter (13) according to a characteristic that is inverse to the characteristic of the preemphasis filter (11) and is a function of the spectral parameter (a.sub.i). A codebook (18, 19) is searched for an optimum fricative value in response to a pitch parameter that is derived by an adaptive codebook (16) from a previous fricative value (v(n)) and a difference between the weighted speech samples and synthesized speech samples which are, in turn, derived from past pitch parameters and optimum fricative values, whereby the difference is reduced to a minimum. Index signals representing the spectral parameter, pitch parameter and optimum fricative value are multiplexed into a single data stream.

Abstract: An arrangement for use with gaseous discharge lamp circuits having power factor capacitors in which the capacitor is disconnected from the circuit when the lamp is not drawing current.

Abstract: An intermittent low intensity light source that is switched on by a drive signal is enhanced by a high intensity light source. The high intensity light source is coupled with the low intensity light source so that at least some light from both sources is projected in a desired direction. The high intensity light source has a brightness or intensity that significantly exceeds that of the low intensity light source. A pulse power source is connected to the high intensity light source and made responsive to the drive signal for pulsing the high intensity light source to emit a brief light pulse before the low intensity light source achieves any substantial precentage of its peak intensity, the light pulse occurring in such close time proximity to the peak intensity of the low intensity light source that persistence of vision in the human eye causes the two light sources blend together visually.

Abstract: This invention is directed to an improved low voltage fluorescent lighting system having two elongated fluorescent lamps. The invention provides an improved simple switching system which allows one or both lamps to be turned on. The improved switching system includes a high capacitance by-pass circuit parallel to one of the fluorescent lamps which, when closed, by-passes sufficient current so that the lamp in parallel will not be lit.

Abstract: An electronic flash device fires one or a pair of flash tube sequentially for continuous shooting photography with a motor driven photographic camera, for substantially continuous illumination or for sequential illuminations at intervals, as well as fire the flash tube a single time for one shot photography. The flash device is provided with a main capacitor and an auxiliary capacitor which selectively energize the flash tube or tubes. The auxiliary capacitor is charged by the main capacitor and discharged to energize the flash tube for a small amount of flash light and short-time restoration of the flash firing circuit. When a pair of flash tubes are employed, they are alternatively actuated for the sequential firing and one of them is actuated for the single time firing. The pair of flash tubes are coupled with each other through a commutation capacitor and switch elements for quick repetition of their firings.

Abstract: A ballast adaptor circuit which makes it possible to convert a conventional two lamp rapid start T12 ballast for operation of two T8 fluorescent lamps and by means of a simple modification that does not require cutting wires or extensive rewiring of the T12 ballast device. The adaptor circuit comprises an auxiliary circuit including a tuned series-parallel LC network connected in parallel with either one or both of the lamps. The LC network is tuned to supply an odd harmonic current to the lamps, preferably the seventh harmonic. Improved starting is achieved by adding a series RC circuit and a SIDAC trigger device to the network to produce voltage pulses at the peaks of the AC supply voltage.

Abstract: An electronic ballast is adapted for operation on regular 120 volt/60 Hz power line voltage and comprises: (i) full bridge rectifier means, (ii) ripple filter means consisting of an LC circuit series-resonant at 120 Hz, (iii) self-oscillating inverter means operating into an LC output circuit parallel-resonant at about 30 kHz, and (iv) means to disable the inverter in case a 30 kHz ground-fault current flows from its output circuit. A key element in achieving high reliability as well as high durability relates to the use of the series-resonant LC circuit instead of the conventional electrolytic capacitor for DC voltage ripple filtering. A key element in achieving high efficiency relates to the use of ground-fault interruption to achieve the required safety from electric shock hazard, thereby obviating the need for the more conventionally used isolation transformer with its attendant added cost and inefficiency.

Abstract: A ballast adaptor circuit which makes it possible to convert a conventional two lamp rapid start T12 ballast for operation of two T8 fluorescent lamps and by means of a simple modification that does not require cutting wires or extensive rewiring of the T12 ballast device. The adaptor circuit comprises an auxiliary circuit including a tuned series-parallel LC network connected in parallel with either one or both of the lamps. The LC network is tuned to supply an odd harmonic current to the lamps, preferably the seventh harmonic. Improved starting is achieved by adding a series RC circuit and a SIDAC trigger device to the network to produce voltage pulses at the peaks of the AC supply voltage.

Abstract: A highly efficient circuit for converting a low level DC voltage to the high voltage necessary for energizing a flash lamp. The circuit is very small and non-complex, it is portable and is quickly recharged, particularly being adaptable for emergency flash uses and for toys such as light swords and laser pistols. A very efficient portion of the circuit, comprising a DC/AC inverter, an AC/DC converter and a voltage multiplier, operating at an appropriate frequency, enables the flash capacitor to always be maintained substantially at peak voltage value with minimum power usage.

Abstract: A power supply apparatus is structured such that the output of an alternating current voltage source (1) is connected to the input of a rectifying circuit (2), a series connection of a first smoothing capacitor (3a), a diode (15) and a second smoothing capacitor (3b) is connected to the output of the rectifying circuit so that the rectifying direction of the diodes may be opposite to the rectifying direction of the rectifying circuit, a first load (4a) is connected in parallel with the series connection portion of the first smoothing capacitor and the diode, and a second load (4b) is connected in parallel with the series connection portion of the second smoothing capacitor and the diode.

Abstract: A ballast for energizing a pair of fluorescent lamps in response to power supplied by an AC line, includes a capacitor connected between one of a pair of heater winding leads which connect to a filament contained in one of the fluorescent lamps, and one of a pair of leads associated with a primary winding of the ballast, the primary winding leads being connected to the AC line. The present ballast realizes a substantial reduction in the amount of power consumed from the AC line when compared to operation of the ballast without the added capacitor.

Abstract: In an electronic flash device for use in a still camera, a calculation circuit means calculates a ratio of the amounts of light to be emitted by a plurality of flash light tubes on the basis of color temperature information and control circuit means controls the emission of light of the respective flash light tubes in such a manner that the ratio of light amount emitted from the respective flash light tubes corresponds to the ratio calculated by the calculation circuit means.

Abstract: A circuit for operating and controlling optical apparatus for viewing an object and making a photographic record thereof and having an illuminating light source and a photoflash light source, the circuit including a pulse width modulator for operating the illuminating light source, a flyback converter circuit and capacitor charging and discharging circuit for operating the photoflash light source, a clock pulse source connected to the pulse width modulator and the flyback converter for operating the same, and a delay circuit for allowing the optics to settle before operation of the photoflash. An energy level control circuit monitors the capacitor voltage and stops application of clock pulses to the flyback converter when the capacitor voltage reaches a desired value. A first visual indicator signals when the desired capacitor voltage is reached, a second visual indicator signals a certain condition in the apparatus, and a circuit gives priority to operation of the second indicator.

Abstract: Discharge apparatus comprises a xenon-filled glass envelope with a common cathode that divides the envelope into two separate gas-containing chambers. Respective anodes are provided in each chamber to cooperate with the common cathode. By placement of the cathode a closer distance to one of the anodes, the impedance of the discharge path between the more closely spaced electrodes is made lower than the impedance of the discharge path in the other chamber. To make the impedance even lower, the pressure of the gas between the closely spaced electrodes is made lower than the gas pressure between the other pair of electrodes. The discharge apparatus is particularly useful in quenchable electronic flash apparatus employing both a flash tube and a low-impedance quench tube.

Abstract: A multiplex strobe light in which several ionized gas flash tubes are fed in parallel from a common power and trigger circuit. The common power circuit has a capacitor which is connected across a charging voltage and all of the flash tubes. The common trigger circuit has an SCR gated on by a zener when the charge on the capacitor reaches the desired voltage. Each flash tube has its own transformer with the secondary connected to its control electrode and the primary connected to a capacitor discharged through the SCR so the flash tubes are turned on simultaneously and share the power capacitor discharge.

Abstract: Circuitry for selectively sustaining a gaseous discharge display panel to splay selected information which circuitry permits the use of a single power supply.

Abstract: Electronic strobe flash apparatus has first and second flashtubes which are fired alternately and repeatedly to produce a composite, extended light flash. A start pulse triggers the first flashtube to cause a first normally charged capacitor to discharge through a primary winding of a transformer, the first flashtube, and a second normally discharged capacitor, thereby firing the first flashtube and charging the second capacitor. The transformer is adapted to produce a flashtube trigger voltage across its secondary winding when current in its primary winding is interrupted. The second capacitor is smaller than the first capacitor so that the voltage across the second capacitor increases more rapidly than the decrease in voltage across the first capacitor during its discharge.

Abstract: A solid state ignition system for generating high frequency and high energy electrical pulses, the system providing improved performance under varying line voltage conditions, improved voltage regulation, and reduced power dissipation, and being effective to produce an improved ionization arc between electrodes effective to initiate fuel oil combustion.

Abstract: A DC circuit for efficiently operating two arc discharge flashlamps. The lamps are parallel connected across a single supply storage capacitor, and a single trigger capacitor is employed in connection and the two alternately activated trigger sources for the two lamps.

Abstract: Electrical lamp ballast system for starting and operating fluorescent lamps with improved efficiency and safety. System includes high leakage reactance autotransformer having primary and secondary windings, and a ballast capacitor connected in series with the secondary winding and two serially connected fluorescent lamps of low starting and operating voltage, the secondary circuit being connected to a tap on the primary winding for reducing the ratio of the ballast power input to the lamp light output. A starting capacitor connected across one of the lamps has a resistor of predetermined resistance connected in shunt therewith to reduce the peak voltage to ground resulting from removal of that lamp from the circuit, so that electrical shock hazard to service personnel is minimized.

Abstract: A circuit for efficiently operating two arc discharge flashlamps. The lamps are series connected and directly coupled through series circuitry across an alternating current (AC) source. A storage capacitor is connected between the junction of the lamps and one terminal of the source. Trigger pulses are alternately applied to the lamps so that the storage capacitor is charged when one lamp flashes and discharged when the other lamp flashes. RC timing circuits energized by the AC source control the time of pulsed ignition of respective lamps with respect to the phase of the AC waveform of the source.

Abstract: The specification discloses a low loss ballast system for reducing the electrical power required to operate fluorescent and other ionized gas lamps as well as several unique starting and operating circuits which can be used in combination with conventional as well as the low loss system described herein.

Abstract: A flash array provided with a number of high voltage combustion flash lamps which are ignited by means of a piezo element. The flashing of two lamps at the same time is prevented by means of melting strips.According to the invention the igniting pulse for a second lamp of the device is passed on via a capacitive circuit element which is formed by the flashed first lamp or a separate capacitor. By using such a capacitor circuit element instead of an ohmic resistance undesired loss of heat is avoided.

Abstract: A circuit arrangement for igniting flash tubes, without using an ignition electrode, and having two main electrodes which are supplied with an ignition pulse parallel to a flash capacitor and an electronic switch, employs an electronic switch which also constitutes a gas discharge path. In particular the electronic switch may be realized as a flash tube.

Abstract: A plurality of flash units mounted as warning, navigational or signal beacons are driven from a remote energy storage power converter with reduced number and or size of discharge current cables by common use of cables combined with sequential flashing such that the discharge current for only one flash lamp is carried by a cable at a given instant. By very close spacing, the sequential flashes may be made to appear simultaneous to the human eye.