Abstract: A switching power source device includes: a direct power source; and a chopper circuit including a pair of input terminals connected to the direct power source and a pair of output terminals connected to a load, the chopper circuit including a first inductor, a second inductor magnetically coupled to the first inductor, a third inductor connected to the first inductor, a switching element causing an augmented current to flow from the direct power source to the first and third inductors while turned on, a constant current element connected to the switching element in series, a rectifier element causing a reduced current to flow through the first and third inductors while the switching element is turned off, and a drive circuit controlling and turning off a gate voltage of the switching element after the switching element is turned on and the augmented current reaches a constant current element saturated state.

Abstract: An arc detection circuit that detects an occurrence of arcing between ballast and a lamp is provided. A transformer has a primary side connected between the ballast and the lamp to receive lamp current and conduct the lamp current from the ballast to the lamp during normal operation. A secondary side of the transformer produces a transformer voltage as a function of the lamp current received by the primary side. The produced transformer voltage is less than a threshold value during normal operation and greater than the threshold value during an occurrence of arcing between the ballast and the lamp. The arc detection circuit reduces the produced transformer voltage and provides it to the ballast so as to shut down the ballast operation.

Abstract: There are provided a DC/DC converter and a driving apparatus having the same. The DC/DC converter includes a DC/DC converter part converting an input power into a predetermined DC power by switching the input power to thereby supply the converted DC power to a light emitting device; and a control part controlling switching of the DC/DC converter part in accordance with a driving signal applied to the light emitting device to thereby control a voltage level of the DC power.

Abstract: An electronic ballast for a light emitting load is provided, and includes a transformer module, a resonance module, a high-frequency push-pull inverter and a driving controller module. The high-frequency push-pull inverter includes a first switch component and a second switch component. The driving controller module is used for generating and providing an asymmetric driving waveform to the first switch component and the second switch component. The asymmetric driving waveform includes a first discharging waveform portion for discharging and turning off the first switch component, and also a second discharging waveform portion for discharging and turning off the second switch component. The first and second discharging waveform portions are different in current amplitudes and time spans.

Abstract: An insulated power supply device includes: an electric power conversion unit, a rectifier, a filter, a detection unit, a control circuit, and a signal transmission unit. The control circuit generates and outputs a control signal for a switching element that controls a current to be flown through a primary side of the electric power conversion unit. The signal transmission unit transmits, to the control circuit, a detection signal by the detection unit for detecting an output current or an output voltage. An output control pulse signal having control information in a duty ratio can be supplied as an outputted control signal individually to both of the control circuit and a secondary side of the electric power conversion unit. The output current or the output voltage can be thereby controlled.

Abstract: A phase comparator is connected between a rectifier and an oscillator in the primary side of the transformer of lighting equipment. The phase comparator obtains rectifier's frequency multiplication signal of pulse DC signal as a reference phase and a phase synchronization signal of a phase angle ? of the AC power signal then transmits to the control of the oscillator, and synchronizes the oscillation frequency of the oscillator and phase synchronization signal with the phase angle ? of rectifier, to avoid flickering of phase adjustment of AC power by TRAIC.

Abstract: The present invention discloses a primary-side controlled switch-mode power supply controller for driving LED with constant current and method thereof as well as an apparatus for controlling switch-mode power supply having the switch-mode power supply controller. The switch-mode power supply controller includes an input dimming phase detection circuit, a multiplier, a turn-on signal control circuit, a zero-crossing detection circuit, a comparator, a trigger and a driving circuit. The circuit controls to drive LED with constant current by means of a primary-side controlled method. The circuit realizes the triac dimming function, ensures a constant output current regardless of a high voltage or a low voltage, and obtains a high power factor. The direct use of the isolation transformer improves the safety of the circuit, and simplifies the peripheral circuit, thereby reducing the cost of the circuit and minimizing the size of the PCB layout, which is favorable in minimizing the product.

Abstract: A driver circuit for a dimmable solid state light source, and devices such as lamps and fixtures incorporating the same, and methods of driving such sources, are provided. A supply voltage circuit provides a supply voltage to a power factor controller circuit, such that the supply voltage is maintained within the high end of a nominal supply voltage operating range of the power factor controller circuit. The driver may also include an open circuit protection circuit for disabling the power factor controller circuit when an open circuit occurs in the load, and/or protection against electromagnetic interference (EMI).

Abstract: A driving circuit system for a gas discharge lamp includes a power circuit having a switch for converting an input voltage into a lamp voltage for driving the gas discharge lamp, a lamp current detecting circuit connected to the power circuit or the gas discharge lamp for detecting a lamp current, a feedback circuit connected to the lamp current detecting circuit for generating a lamp current feedback signal, a constant power control circuit for generating a corrected current reference signal, and a power control circuit connected to the feedback circuit, the constant power control circuit, and the switch of the power circuit for generating a first modulating signal in accordance with the lamp current feedback signal and the corrected current reference signal for driving the switch to turn on or off, thereby substantially maintaining a lamp power of the gas discharge lamp at a constant value.

Abstract: The transmission branch of an interface circuit has a transformer. On the input side there are applied to the transformer, for example from a controller, high-frequency impulses. The output side of the transformer controls a switch, such as for example a power transistor, which modulates the desired digital signals onto a connected bus line.

Abstract: A driver circuit, solid state light (SSL) source assembly including same, and a method of driving an SSL source are provided. The driver circuit includes a rectifier, an inverter, a transformer, a PFC circuit, and a frequency control. The rectifier receives an AC voltage and provides an unregulated DC voltage. The inverter includes two switches, and receives respective control signals to operate these, to generate a resonate AC signal from the unregulated DC voltage. The transformer includes a primary winding coupled to the inverter, a secondary winding to be coupled to an SSL source through an output stage, and a feedback winding. The PFC circuit controls the inverter in response to signals representative of the unregulated DC voltage and the inverter's current. The frequency control generates the control signals to control the inverter's switching frequency in response to signals representative of the output stage's current and the feedback winding's current.

Abstract: A lighting apparatus, a lighting system and a lighting control method are disclosed. The lighting apparatus includes an LED module, a heat sink for emitting heat generated from the LED module, a rectifier for rectifying an input commercial AC power, a transformer including a main coil and an auxiliary coil to transform the rectified power, and an electronic module for biasing a current used to drive the LED module based on the input voltage transported via the auxiliary coil.

Abstract: There are provided an LED driving apparatus and an LED driving method thereof. The LED driving apparatus includes: a light emitting unit including one or more LEDs, a rectifying unit rectifying an input signal to generate a first signal; a signal conversion unit inverting a waveform of a first signal to generate a second signal; and an operation unit arithmetically operating the first and second signals. A plurality of AC signals each having a different waveform are arithmetically operated to generate a signal having a small amount of a ripple component, and an LED is driven by the signal, thus preventing a lifespan of the LED from being shortened by omitting a smoothing electrolytic capacitor, one of main causes shortening the lifespan of an LED driving circuit.

Abstract: A circuit for powering a light source includes a filter, a transformer, and a controller. The filter receives an input voltage and filters the input voltage to provide a regulated voltage. The transformer converts the regulated voltage to an output voltage to power the light source. The controller generates a driving signal to alternately operate the switch between a first state and a second state. The controller corrects a power factor of the circuit by controlling time durations of the first state and the second state, such that an input current decreases to a predetermined level during the second state and increases from the predetermined level to a peak level proportional to the input voltage during the first state. The controller controls the ratio of time in the first state to time in the second state to adjust an output current flowing through the light source to a target level.

Abstract: A power control system includes a transformer and a controller regulates a current on a secondary-side of the transformer based on a primary-side signal value. In at least one embodiment, the secondary-side current is a current out of a filter coupled to a rectifier and the secondary-side of the transformer and into a load. In at least one embodiment, the primary-side signal value is a sample of a current in the primary-side windings of the transformer. In at least one embodiment, the primary-side signal value represents a sample value of a primary-side transformer current. Proper timing of sampling the primary-side signal value substantially eliminates contributions of a transformer magnetizing current from the primary-side transformer current sample. Sampling the primary-side signal value when contributions of the transformer magnetizing current are substantially eliminated allows at least an average of the secondary-side current to be determined from the primary-side signal value.

Abstract: The present disclosure relates to a light driving apparatus which may stably drive an LED light at a normal operation by feeding back the output voltage of the LED light and stably drive the LED light at an abnormal operation by feeding back the voltage supplied to the LED light, and the light driving apparatus includes: a rectifier circuit; a transformer circuit; a power factor correction circuit; a smoothing circuit; a constant-current driving circuit; a dimming control circuit; a photo-coupler; a sample and hold circuit; a first photo-coupler driving circuit for feeding back the voltage output from the sample and hold circuit and applying the feedback voltage as a driving voltage of the photo-coupler; and a second photo-coupler driving circuit for feeding back the voltage output from the smoothing circuit and supplied to the LED module and supplying the feedback voltage as a driving voltage of the photo-coupler.

Abstract: When an operator operates an operation tool of a dimming operation terminal device in order to set the brightness of a lighting load to desired brightness, an energization electric signal, for example, a voltage level detected by a dimming control section changes. The dimming control section generates a dimming signal modulated according to the voltage level. Power supply to the dimming control section is performed by an insulated auxiliary power supply. Transmission of the dimming signal is performed via an insulating section.

Abstract: A half bridge resonant topology ballast for use with a fluorescent lamp includes a resonant tank and a resonance inductor having a secondary winding. The secondary winding is arranged for series connection to the fluorescent lamp, and the secondary winding provides a voltage that reduces the resonant tank voltage.

Abstract: The current invention provides a power supply that includes an igniter that generates an ignition voltage for igniting a DC lamp; an auxiliary power stage that outputs an auxiliary voltage for sustaining sufficient current in the DC lamp after the DC lamp is ignited; a voltage conversion stage coupled to the auxiliary power stage and generating a voltage at a level that is higher than the auxiliary voltage; and a switch that couples the auxiliary voltage to the DC lamp and the voltage conversion stage for a predefined period of time.

Abstract: Solid state light sources are compatible with AC phase-cut dimmers. The light sources may have switching mode power supplies having primary and secondary sides that are in first and second circuit parts that are electrically isolated from one another. Information regarding a waveform of input electrical power is extracted in the first circuit part and passed to a controller in the second circuit part by way of a galvanic isolator. Additional isolated paths may be provided to provide bi-directional exchange of information between the first and second circuit parts and/or to provide for the exchange of additional information relevant to control. The signal path from the first side to the second side may have a low latency.

Abstract: The present invention discloses an open loop LED driving circuit, having a turn-on period and a turn-off period, the circuit comprising: a power stage, used to store a magnetic energy supplied from a voltage source during the turn-on period and deliver the magnetic energy to a set of LEDs during the turn-off period; and a control unit, having a turn-off period control terminal coupled to the voltage source, and a channel of which a first terminal is coupled to the power stage and a second terminal is coupled to a reference ground, wherein the channel is switched on at a time according to the voltage of the voltage source to determine the turn-off period.

Abstract: A method of driving a light source includes receiving an alternating current (“AC”) voltage from outside, generating a first direct current (“DC”) voltage based on the AC voltage, generating a second DC voltage, corresponding to a difference between a driving voltage of a light source part and the first DC voltage, based on the first DC voltage, and outputting a sum of the first DC voltage and the second DC voltage to the light source part

Abstract: A circuit for driving a light-emitting diode (LED) light source includes a converter, a saw-tooth signal generator, and a controller. The converter includes a switch which is controlled by a driving signal. The converter provides a sense signal indicating the current through said LED light source. The saw-tooth signal generator generates a saw-tooth signal based on the driving signal. The controller generates the driving signal based on signals including the saw-tooth signal and the first sense signal to adjust the current through the LED light source to a target level and to correct a power factor of the driving circuit by controlling an average current of the input current to be substantially in phase with said input voltage.

Abstract: A method is provided for operating at least one LED by a switched-mode regulator circuit to which a DC or a rectified AC voltage is supplied and which provides a supply voltage for at least one LED by a coil and a switch clocked by a control/regulation unit. When the switch is activated, power is temporarily stored in the coil and is discharged through a diode and through at least one LED when the switch is deactivated and the current flows through the LED through a first power storage element which is coupled to a second power storage element. The first power storage element just reaches its maximum capability of storing power due to the current flowing through the LED. A rising current is supplied to the second power storage element such that the time can be detected when the first power storage element recovers its capability of storing power.

Abstract: A cathodoluminescent lighting system has a light emitting device having an envelope with a transparent face, a cathode for emitting electrons, an anode with a phosphor layer and a conductor layer. The phosphor layer emits light through the transparent face of the envelope. The system also has a power supply for providing at least five thousand volts of power to the light emitting device, and the electrons transiting from cathode to anode are essentially unfocused. Additional embodiments responsive to triac-type dimmers with intensity and color-changes in response to dimmer control. A power-factor-corrected embodiment is also disclosed.

Abstract: An electronic ballast for driving a gas discharge lamp comprises an inverter circuit that operates in a partially self-oscillating manner. The inverter circuit comprises a push-pull converter having a main transformer having a primary winding for producing a high-frequency AC voltage, semiconductor switches electrically coupled to the primary winding of the main transformer for conducting current through the primary winding on an alternate basis, and gate drive circuits for controlling the semiconductor switches on a cycle-by-cycle basis. The drive circuits control (e.g., turn on) the semiconductor switches in response to first control signals derived from the main transformer, and control (e.g., turn off) the semiconductor switches in response to second control signals received from a control circuit. The control circuit controls the semiconductor switches in response to a peak value of an integral of an inverter current flowing through the inverter circuit.

Abstract: An ignition circuit arrangement and method for a discharge lamp, with which there is associated a supply circuit for providing an ac supply voltage to the lamp, includes an ignition transformer which is connected to a trigger circuit on the primary side and to the lamp on the secondary side for transmitting an ignition pulse; an input energy source for the ignition trigger circuit; a first switch means in the trigger circuit and a control means which actuates the first switch means. To assist with the ignition process, an energy storage means controllable by the control means, in particular a voltage source controllable by the control means, is arranged in the supply circuit in series with the gas-discharge lamp. The controllable energy storage means serves to provide an additional energy supply during the ignition process beyond the actual ac supply for the lamp.

Abstract: A power converter and power conversion method converts an input AC signal to a voltage usable by a load while reducing power consumption, thereby making the converter and method suitable for a wider range of applications. A rectifier receives the AC input signal and outputs a rectified voltage Vs, a controller has a power input connected to Vs and outputs two out-of-phase signals, two transistors are connected in series between Vs and a ground and each of the two transistors has a gate connected to a respective one of the two out-of-phase signals, and a transformer that has a primary coil connected to a node between the two transistors and a secondary coil connected to a load feeds back current from the secondary coil to the power input of the controller to reduce power consumption.

Abstract: The invention relates to an electronic operating device for a gas discharge lamp having: a DC/DC voltage converter, a power factor correction circuit, an inverter, a lamp inductor, and having a full bridge with two half bridges which can be controlled separately, wherein the DC/DC voltage converter additionally acts as a voltage step-down converter, and the inverter additionally has the following functions: lamp current regulation, the function of stepping down the voltage to the lamp voltage, and resonant ignition.

Abstract: An LED driver with open loop dimming including a full wave rectifier circuit, a DC/DC converter, and an oscillator circuit. The rectifier is configured to receive an input voltage in the form of an AC conductive angle modulated voltage and to provide a rectified voltage. The DC/DC converter converts the rectified voltage to an output voltage and an output current, where the output current has a magnitude which varies proportionately with a square of a quadratic mean of the input voltage. The oscillator circuit controls switching of the DC/DC converter with constant frequency and constant duty cycle. The DC/DC converter may be a flyback converter and may include a transformer operated in DCM. The driver may include output voltage and/or output current limit. The output current may be limited when the input voltage is within normal operating range of an AC line voltage from which the input voltage is derived.

Abstract: A power converter and power conversion method converts an input AC signal to a voltage usable by a load while reducing power consumption, thereby making the converter and method suitable for a wider range of applications. A rectifier receives the AC input signal and outputs a rectified voltage Vs, a controller has a power input connected to Vs and outputs two out-of-phase signals, two transistors are connected in series between Vs and a ground and each of the two transistors has a gate connected to a respective one of the two out-of-phase signals, and a transformer that has a primary coil connected to a node between the two transistors and a secondary coil connected to a load feeds back current from the secondary coil to the power input of the controller to reduce power consumption.

Abstract: A lamp base (2) for a high-pressure discharge lamp comprises an ignition transformer (1000), which is placed in the interior (214) of the lamp base (2) and which serves to ignite the gas discharge inside the high-pressure discharge lamp. To this end, the ignition transformer (1000) comprises a core on which its windings (1001, 1002) are placed. The core is formed by a first core part (1004) and by at least one second core part (1005, 1006, 1007), which are each made of a ferromagnetic or ferrimagnetic material and are separated by at least one gap (10078). The first core part (1004) has a cylindrical section on which the windings (1001, 1002) of the ignition transformer (1000) are placed, and core parts (1004, 1005, 1006, 1007) are formed in such a manner that the core, apart from the at least one gap (1008), has a closed shape.

Abstract: Methods and apparatus for dimming light sources are described herein. In certain embodiments, a bias circuit selectively biases a solid state switch during a portion of half-cycle of a line voltage after a settable delay. In some embodiments, the delay of the bias circuit is adjustable by a user, which varies the amount of energy provided to a light source, and the light generated there from. A charge circuit biases the switch for a period of time in the event the bias circuit experiences an operating condition (a ringing current) that may cause the switch to become open during the half-cycle of the line current. As a result of the charge circuit, the light source coupled to the line current does not experience substantial flickering and is compatible with low power compact fluorescent lights. The dimmer can be combined with other components to form a light harvesting system.

Abstract: Methods and apparatus for dimming light sources are described herein. In the described examples, a bias circuit selectively biases a switch during a half-cycle of a line current after a delay. In some examples, the delay of the bias circuit is adjustable by a user to adjust the amount of light a light source emits. A charge circuit substantially biases the switch for a period of time in the event the bias circuit experiences an operating condition that may cause the switch to become open during the half-cycle of the line current. As a result of the charge circuit, the light source coupled to the line current does not experience substantial flickering.

Abstract: An overcurrent breaking controller for a lamp and lantern comprises a trigger control unit connected to an AC power, a current transformer connected between the trigger control unit and the lamp and lantern, and an overcurrent restraint unit connected to the trigger control unit and the current transformer. When the lamp and lantern works with a current exceeding a rated power, the overcurrent restraint unit instantly controls the trigger control unit to stop triggering; after the current drops, the AC power is re-supplied to make the lamp and lantern become bright. Thus, the current of the consumed power of lamp and lantern is restrained and automatically returns for achievement of forced power saving and easy installation.

Abstract: An object of the invention is to provide a magnetron drive power supply for performing stable inverter operation and good in development efficiency. According to the invention, the potential difference between emitter terminal potential (121) of a switching element (12) and minus terminal potential (101) of a rectifying device (1) can be minimized and stable switching operation and abnormal voltage detection can be realized. There can be provided an optimum magnetron drive power supply responsive to the power supply voltage and good in development efficiency because of unification of chassis, etc., with commonality of component placements, particularly ground connection positions (41) and filament output positions (42) of a magnetron drive power supply in the rated voltage range of 100 V to 120 V and a magnetron drive power supply in the rated voltage range of 200 V to 240 V.

Abstract: There are provided a display apparatus and a display method, with which compressed image data that is to be decompressed can be transmitted to the display apparatus in an environment in which a transmission capacity is not always secured, and good image display is realized. An example of the display apparatus is an active matrix display apparatus formed by using thin-film transistors formed on an insulating substrate. In the active matrix display apparatus, a circuit that receives an image data signal from an external system via a non-contact transmission path and amplifies the image data signal, a circuit that processes the image data signal, and a memory circuit that stores the processed image data are integrated on the insulating substrate.

Abstract: An inverter converts input voltage to AC driving voltage to supply it to a load. Secondary coil of an output transformer are connected to the load. Secondary coil of a main transformer are connected to the primary coil of the output transformer. A driving circuit applies switching voltage alternately repeating the input voltage and ground voltage to the primary coil of the main transformer.

Abstract: An output of a rectifying circuit (6), which rectifies commercial AC power, is supplied to an inverter (12) through a power factor correction circuit (8). The output of the inverter (12) is voltage-transformed in a transformer (16), rectified in a rectifying circuit (18) and is applied to a xenon lamp (2). A secondary winding (22s) of a transformer (22) of an igniter (20) is connected between the rectifying circuit (18) and the xenon lamp (2) in order to generate an arc in the xenon lamp (2). A pulse generator provides a pulse for a short time period to a primary winding (22p) of the transformer (22). An auxiliary power supply (26) supplies arc-sustaining current prepared based on the commercial AC power to the junction of the rectifying circuit (18) and the secondary winding (22s) of the transformer (22).

Abstract: A method of polymerizing by a free radical polymerization mechanism, product formed thereby, and apparatus for performing this method, are disclosed. The composition to be polymerized by the free radical polymerization mechanism is irradiated by a substantially constant radiation, the radiation being substantially without pulsation. The use of the substantially constant radiation without pulsation reduces premature termination of the polymerization. The substantially constant radiation can be the output of a lamp powered by a constant current, direct current power supply.

Abstract: A lamp base (2) for a high-pressure discharge lamp comprises an ignition transformer (1000), which is placed in the interior (214) of the lamp base (2) and which serves to ignite the gas discharge inside the high-pressure discharge lamp. To this end, the ignition transformer (1000) comprises a core on which its windings (1001, 1002) are placed. The core is formed by a first core part (1004) and by at least one second core part (1005, 1006, 1007), which are each made of a ferromagnetic or ferrimagnetic material and are separated by at least one gap (10078). The first core part (1004) has a cylindrical section on which the windings (1001, 1002) of the ignition transformer (1000) are placed, and core parts (1004, 1005, 1006, 1007) are formed in such a manner that the core, apart from the at least one gap (1008), has a closed shape.

Abstract: A starting apparatus for a high-pressure discharge lamp provided with an auxiliary starting electrode, has a series resonant circuit for the purpose of generating the starting voltage for the high-pressure discharge lamp. The resonant inductance of the series resonant circuit includes the primary winding of a transformer, whose secondary winding is provided for the purpose of applying the starting voltage to the auxiliary starting electrode (Z) of the high-pressure discharge lamp. The invention also relates to a high-pressure discharge lamp, in particular to a vehicle headlight lamp, having such a starting apparatus arranged in the lamp base.

Abstract: An apparatus for providing convenient transforming of electrical energy from a first voltage level to a second voltage level, includes a housing having an end wherein the end includes a conductive threading and a contact for making an electrical connection with a light bulb socket. The apparatus also includes a transformer electrically connected to the electrical connection for receiving power through the light bulb socket and transforming the received electrical energy from the first voltage level to the second voltage level. There is a connection electrically connected to outputs of the transformer to provide power at the second voltage level. The converted power can be used to power a DC-driven device such as an LED.

Abstract: A lighting control system provides variable arc current to one or more fluorescent gas discharge lamps and provides a heating voltage to the lamp electrodes. The system includes a start-up circuit which includes circuitry for providing a starting voltage to an output power conditioning circuit. The latter drives a switching unit to control the application of DC power to the fluorescent gas discharge lamps and to provide an operating voltage to an input power factor correction circuit. The input power factor correction circuit boosts the converted DC power and the operating voltage. The start-up circuit includes a plurality of voltage doubling rectifier circuits and a plurality of zener diodes which receive the operating voltage and are electrically connected to the input power factor correction circuit and the output power conditioning unit so as to provide a regulated bias voltage supply to the output power conditioning unit and to the input power factor correction circuit.

Abstract: A brightness-regulating voltage-transforming circuit includes a pulse-width modulator (PWM); a transformer connected at a secondary side to a high-pressure discharge lamp; a voltage-transforming circuit having two transistors connected at bases to outputs of the PWM for the latter to control working frequencies thereof; and a brightness control circuit including a transistor connected at a collector to a middle tap of the transformer and at a base to the PWM for the PWM to control the lamp brightness, and a diode connected at an end to a juncture of a primary side of the transformer and an end of a buffer inductance, and at another end to a voltage source. When the transistor of the brightness control circuit is cut out, energy stored in the buffer inductance is regenerated and sent to the voltage source via the diode, enabling the lamp to have reduced noise interference and increased working efficiency.

Abstract: A combination-type high frequency inverter connects an isolation leakage transformer, a smoothing condenser, a resonance condenser, a first field-effect transistor and a second field-effect transistor to a diode bridge and rectifies the voltage of an AC power source in a non-smoothing rectification manner. A load circuit has a secondary winding of an isolation leakage transformer, a fluorescent lamp and a condenser. The ‘on’ duration of the first field-effect transistor is variable. The duration of on-duty of the second field-effect transistor is fixed. Adjusting charge voltage on the smoothing condenser changes the high frequency output voltage and the load characteristics. Load characteristics, optimal for the current mode, are given to the fluorescent lamp, in accordance with whether the flourescent lamp is in either start-up or luminance mode.

Abstract: A dielectric-barrier discharge lamp light source with a dielectric-barrier discharge lamp, the light source including a discharge plasma space filled with a discharge gas in which excimer molecules are formed by dielectric-barrier discharge, two electrodes adapted to induce a discharge phenomenon in the discharge gas, at least one of the two electrodes being separated from the discharge gas by a dielectric, and a power supply for impressing a substantially cyclical, high-voltage alternating current on the two electrodes of the dielectric-barrier discharge lamp in a manner that when the power supply completes a discharge in the dielectric-barrier discharge lamp and the voltage impressed on the dielectric-barrier discharge lamp changes for a subsequent discharge, there is a period of gradual change in a lamp voltage waveform (Vs(t)) before reaching a voltage required for beginning of the subsequent discharge, wherein subsequent to the period of gradual change, the voltage impressed on the dielectric-barrier dis

Abstract: A circuit for operating a discharge lamp includes input terminals for connection to a supply voltage source and a first apparatus coupled to the input terminals for generating a low-frequency alternating current from a supply voltage delivered by the supply voltage source. A second apparatus is coupled to the input terminals for generating from the supply voltage a further current which is superimposed on the low-frequency alternating current. The polarity of the further current is the same as that of the low-frequency alternating current. As a result, instabilities do not arise in the discharge arc of a high-pressure discharge lamp operated by the circuit.

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: A frequency-modulated converter with a series-parallel resonance, particularly for driving any ohmic or inductive load, including gas discharge tubes, wherein a commutating voltage switch in the form of a transistor is provided and is connected in series between a negative electrode of a direct current voltage source and a first terminal of an inductor, and a pulse generator circuit is provided between the voltage source and the transistor's control electrode and the inductor's second terminal is connected to the primary winding of a transformer. A first capacitor and rectifier diode are also provided in a first and second parallel branch respectively between the transistor's charge receiving and charge emitting electrodes, and a second capacitor is provided across the voltage source's electrodes, and a smoothing capacitance is provided for the voltage source, the second capacitor being connected in series with the inductor via the diode.