Abstract: A system and apparatus to reduce current peaking in notification appliances are described. The apparatus may include a current peaking compensation circuit comprising two or more transistors and one or more capacitors configured to reduce a start-up frequency of a pulse-width modulated signal during a first time period and to add a time constant decaying voltage across a resistor divider network to increase a reference voltage during the first time period. Other embodiments are described and claimed.

Abstract: A light emitting apparatus wherein, after setting a voltage of a light emitting luminance into a gate of the driving transistor, until setting a light emission controlling transistor at an electrically conducting state, a control signal changing toward a voltage of an opposite electrode of the light emitting element is supplied to the other terminal of the capacitor constructed such that an electro-conductive layer supplied with the control signal and a semiconductor layer forming the terminal of the driving transistor at the side of the light emitting element, a semiconductor layer forming a terminal of a transistor different from the driving transistor and connected to the terminal of the driving transistor at the side of the light emitting element, or an electro-conductive layer connected to the terminal of the driving transistor at the side of the light emitting element are formed so as to face through an insulating layer.

Abstract: Charge corresponding to a potential difference between electrodes of an electroluminescence element is accumulated in a period in which the electroluminescence element emits light; the potential difference is detected without decrease in the luminance at the time of light emission of the electroluminescence element; and a reference potential of one electrode of the electroluminescence element is changed based on the detected potential difference, so that reduction in luminance of the electroluminescence element due to deterioration of the electroluminescence element is compensated.

Abstract: A LED dimming device, and a LED dimming and a driving circuit using such LED dimming device are discussed. In present embodiment, the LED dimming device multiplexes an inputting switch and/or a sampling module of the LED driving circuit for dimming. such LED dimming device will not affect the sine waves of input current, in such a way, power factor and work efficiency will be increased while the harmonic coefficient and interference signal will be reduced.

Abstract: This disclosure describes systems, methods, and apparatuses for impedance-matching radio frequency power transmitted from a radio frequency generator to a plasma load in a semiconductor processing chamber. Impedance-matching can be performed via a match network having a variable-reactance circuit. The variable-reactance circuit can comprise one or more reactive elements all connected to a first terminal and selectively shorted to a second terminal via a switch. The switch can comprise a bipolar junction transistor (BJT) or insulated gate bipolar transistor (IGBT) controlled via bias circuitry. In an on-state, the BJT base-emitter junction is forward biased, and AC is conducted between a collector terminal and a base terminal. Thus, AC passes through the BJT primarily from collector to base rather than from collector to emitter. Furthermore, the classic match network topology used with vacuum variable capacitors can be modified such that voltages do not overload the BJT's in the modified topology.

Abstract: An emergency lighting module for providing emergency power to a solid state luminaire is provided. The emergency lighting module includes a control circuit configured to detect a line voltage, a first input configured to receive an input voltage from the solid state luminaire, and a bidirectional booster/charger circuit coupled to the microcontroller and configured to charge a battery using the input voltage. The bidirectional booster/charger circuit is further configured to provide an output voltage. The emergency lighting module is configured to provide the output voltage to the solid state luminaire in response to a reduction of the line voltage.

Abstract: According to one embodiment, a luminaire includes a housing, a cable run, and a noise filter circuit. A lighting-circuit-integrated lamp is arranged in the housing. The cable run is configured to supply an external power to the lighting-circuit-integrated lamp. The noise filter circuit is provided in the cable run and reduces a noise terminal voltage.

Abstract: An organic light-emitting diode (OLED) pixel circuit is provided, and if a circuit configuration (5T1C) thereof collocates with suitable operation waveforms, a current flowing through an OLED in the OLED pixel circuit may not be changed along with the power supply voltage (Vdd) which may be influenced by an IR drop, and may not be varied along with the threshold voltage (Vth) shift of a thin film transistor used for driving the OLED. Accordingly, the brightness uniformity of the applied OLED display can be substantially improved.

Abstract: A light-emitting element driver circuit is disclosed in embodiment of the invention. The light-emitting element driver circuit includes a driver unit for generating a driving current to the light-emitting element; a data storage unit for storing a threshold voltage of the driver unit and current data signal voltage; and a control unit being controlled to be conducted during a light emitting period so that the driver unit generates a driving current in response to the threshold voltage and current data signal voltage stored in the data storage unit.

Abstract: A low output voltage driver circuit for a light-emitting device is provided according to exemplary embodiments of the present invention. Also, an offset voltage cancellation and/or level shifter is incorporated into the driver circuit to increase the accuracy of the driving current. In addition, an error detection circuit and method are employed in order to adaptively detect the minimum output voltage of the inventive driver circuit.

Abstract: Aspects of the disclosure provide a circuit. The circuit includes a first switch, a second switch and a controller. The first switch is switched on and off to allow a boost circuit to transfer electric energy from an input power supply to a capacitor to generate an intermediate power supply having a higher voltage than the input power supply. The second switch is switched on and off to allow a buck circuit to provide a driving voltage based on the intermediate power supply to drive a load device, and to regulate a current to the load device. The controller is configured to provide a first signal to the first switch and a second signal to the second switch to switch on and off the first switch and the second switch.

Abstract: This disclosure relates to a display device that compensates for a threshold voltage of a driving TFT, a voltage drop of a supply voltage source, and a mobility of the driving TFT. The display device can include a plurality of pixels. At least one pixel can include components such as a first capacitor, a second capacitor, a data transistor, a control transistor, an emission transistor, an initialization transistor, a driving transistor and a light emitting diode (LED) among other components.

Abstract: A control circuit of a DC/DC converter stabilizing driving a current while supplying a driving voltage to a load comprises a current detection circuit for comparing a current detection signal indicative of a current flowing through a switching transistor of the DC/DC converter with a predetermined threshold to generate an OFF signal, a timer circuit for generating an ON signal that is asserted after a predetermined time period has elapsed since an assertion of the OFF signal, a pulse generation circuit for generating a pulse signal, and a driver for driving the switching transistor based on the pulse signal, where the timer circuit includes a first capacitor, a current source for generating a charging current, an arithmetic circuit for generating a threshold voltage, and an first comparator configured to compare a voltage of the first capacitor and the threshold voltage.

Abstract: Disclosed is related with a LCD technology, and particularly to a driver of promoting pixel charging ability of a thin film transistor and a method thereof. The driver of promoting pixel charging ability of a thin film transistor comprises a thin film transistor, a first capacitor and a second capacitor. The source of the thin film transistor is coupled to the first capacitor and the second capacitor respectively. As the drain voltage switches from positive polarity to negative polarity or from negative polarity to positive polarity, a voltage different between a source voltage stored by the thin film transistor and the first capacitor voltage is higher than a predetermined value. The present invention is capable of promoting the charge current and the pixel charging ability. Meanwhile, the requirement of the metal line width can be diminished to improve aperture ratio and raise transmittance of product.

Abstract: There are provided a light emitting diode (LED) driving device allowing for an increase in an LED driving rate by discharging a charge stored in a capacitor during a certain period of time and a method thereof. The LED driving device includes: a driving unit detecting a current, as a voltage, the current flowing across an LED unit having at least one LED, controlling the current flowing across the LED unit according to a comparison result between the detected voltage and a reference voltage having a pre-set voltage level, and having a capacitor stabilizing an operation of the LED unit when the LED unit is driven; and a discharging unit discharging a charge stored in the capacitor during a pre-set discharge time when the LED unit is initially driven.

Abstract: A state cycling apparatus uses a capacitor instead of complicated and expensive microcontroller to fulfill a state cycling function of a system. The state cycling apparatus includes an internal circuit in the system connected to the capacitor. In a first embodiment, the internal circuit reads the voltage level on the capacitor at power on to determine a current state for the system, and writes the voltage level corresponding to a next state of the system to the capacitor. In a second embodiment, the system reads the state data stored in the internal circuit to determine a current state for the system at power on, the capacitor is charged during the system is under power on, and the capacitor provides power for the internal circuit to store a state data after the system is powered off.

Abstract: A state cycling apparatus uses a capacitor instead of complicated and expensive microcontroller to fulfill a state cycling function of a system. The state cycling apparatus includes an internal circuit in the system connected to the capacitor. In a first embodiment, the internal circuit reads the voltage level on the capacitor at power on to determine a current state for the system, and writes the voltage level corresponding to a next state of the system to the capacitor. In a second embodiment, the system reads the state data stored in the internal circuit to determine a current state for the system at power on, the capacitor is charged during the system is under power on, and the capacitor provides power for the internal circuit to store a state data after the system is powered off.

Abstract: A charge recycling device for a panel display apparatus is disclosed. The charge recycling device includes one or more storage capacitors, and one or more switch modules coupled to the one or more storage capacitors and coupled to a plurality of load capacitors via a plurality of source driving nodes, for controlling currents between the plurality of load capacitors and the one or more storage capacitors. During a charge recycling period, the one or more switch modules are arranged to recycle charges stored in the plurality of load capacitors to the one or more storage capacitors. During a charge reutilization period, the one or more switch modules are arranged to redistribute the recycled charges to the plurality of load capacitors.

Abstract: A system and apparatus to reduce current peaking in notification appliances are described. The apparatus may include a current peaking compensation circuit comprising two or more transistors and one or more capacitors configured to reduce a start-up frequency of a pulse-width modulated signal during a first time period and to add a time constant decaying voltage across a resistor divider network to increase a reference voltage during the first time period. Other embodiments are described and claimed.

Abstract: A light-emitting diode module is provided that includes a housing and a printed circuit board, which is connected to a light-emitting diode and which has an LED driver, a control module, and a circuit arrangement. The circuit arrangement has a DC/DC converter and a bypass connected in parallel to the DC/DC converter. The bypass is activatable by a comparator circuit. The comparator circuit is arranged between an input of the circuit arrangement and the DC/DC converter and detects the level of an input voltage of the circuit arrangement and compares it with a first and second threshold value. The comparator circuit activates the bypass when the input voltage is below the first threshold value and deactivates the bypass when the second threshold value is exceeded.

Abstract: Disclosed is a pixel capable of finely controlling the amount of current and increasing the voltage range of a data signal. A pixel includes an organic light emitting diode, a first transistor, a storage capacitor, a load and an amplifier. The first transistor is coupled between a scan line and a data line, and supplies a data signal supplied to the data line to a first node when a scan signal is supplied to the scan line. The storage capacitor is coupled between the first node and a first power source, and charges a voltage corresponding to the data signal. The load is coupled between the organic light emitting diode and the first power source. The amplifier controls a voltage applied to the load corresponding to the voltage charged in the storage capacitor.

Abstract: A circuit arrangement for driving a light source, in particular, a light-emitting diode, comprises a first adjustable current path (1), that connects a terminal (BAT_IN) for a battery to a terminal (CAP_IN) for a capacitor, a second current path (2) that connects the terminal (CAP_IN) for a capacitor to a terminal (LED_OUT) for a light source, and a third adjustable current path (3) that connects the terminal (BAT_IN) for a battery to the terminal (LED_OUT) for a light source. A control unit (CTRL) is provided that has a control input (IN) and is set up to adjust current intensities (I_CHRG, I_CAP, I_DIRECT) on the first, second and third control paths (1, 2, 3), respectively, as a function of control signals (I_in) that can be applied to the control input (IN). A method for operating a light source, in particular, a light-emitting diode, is also proposed.

Abstract: A light emitting element drive device of the present invention includes a light emitting element; a drive unit for driving the light emitting element; an electricity storage element capable of storing electric power; a battery power supply capable of supplying electric power to the electricity storage element; and a boost chopper circuit having an inductor, for boosting voltage by opening and closing a switching element. The drive unit is switchable between three states: a storing state in which electric power from the battery power supply is stored in the electricity storage element; a first discharging state in which the electric power stored in the electricity storage element is supplied to the light emitting element; and a second discharging state in which electric power from the battery power supply is boosted by the boost chopper circuit and is supplied to the light emitting element.

Abstract: Disclosed herein is a light-emitting panel including: an organic electroluminescence element adapted to emit electroluminescence light toward a transparent substrate; a pixel circuit formed on the transparent substrate and adapted to drive the organic electroluminescence element; a color filter formed not only between the transparent substrate and organic electroluminescence element but also immediately on or above the pixel circuit; and a conductive layer formed between the pixel circuit and color filter, the conductive layer being more conductive than the color filter.

Abstract: A switch status detection circuit is provided, including three input terminals and a ground terminal. Two input terminals connect to a power supply via respective switches, receiving a respective voltage signal. The third connects to the power supply, receiving a neutral signal. A neutral synchronization circuit, between the third and the ground terminal, generates a positive pulsed current signal as a function of the neutral signal. Two capacitors, each with a respective first terminal connected to a corresponding input terminal, and a respective second terminal connected to the ground terminal, are charged by the current signal when the capacitor's corresponding switch is in an off state. Respective output terminals are coupled to each capacitor's first terminal to provide respective control signals, indicating the respective switch's state as a function of a voltage level across that capacitor. Each control signal has a logic level corresponding to its respective switch's state.

Abstract: An electronic ballast is provided for powering one or more discharge lamps independently connected in parallel. An inverter having a pair of switching elements converts a DC supply signal into AC power. A transformer has a primary winding coupled to an output terminal of the inverter. A load circuit includes independently operable discharge lamp circuits coupled in parallel with each other and across a secondary winding of the transformer. An inductance control circuit includes an inductive element coupled in series with the primary winding of the transformer and a bi-directional switch coupled in parallel across the inductive element. A switch state of the bi-directional switch is controllably adjustable between first and second switch states and in accordance with a desired duty ratio. A magnitude of a voltage across the secondary winding of the transformer and thereby across each lamp circuit is dependent on the switch state of the bi-directional switch.

Abstract: A capacitor charging apparatus includes a transformer and an output capacitor which is to be charged using the current that flows through the secondary coil of the transformer. A control circuit charges the output capacitor by controlling the switching operation of a switching transistor provided on a path of the primary coil of the transformer. A voltage monitoring terminal is connected to a tap provided to the secondary coil of the transformer. A switching control unit receives a monitoring voltage that occurs at the voltage monitoring terminal, and controls the switching operation of the switching transistor according to the monitoring voltage. A protection circuit monitors the monitoring voltage. In a case in which continues to be satisfied with respect to the monitoring voltage, the switching control operation of the switching control unit for the switching transistor is stopped.

Abstract: A driving integrated circuit (driving IC) connected to a display panel by a chip on glass (COG) method includes a pair of bumps electrically coupled to a test pad of the display panel; a power source electrically coupled to a first bump of the pair of bumps; a circuit device electrically coupled between a ground terminal and a second bump of the pair of bumps; and a node measuring unit for measuring a voltage at a node between the second bump and the circuit device.

Abstract: An exemplary current regulating circuit of LED string includes a capacitor, an inductor, a diode, a switch and a detection circuit. First and second terminals of the capacitor respectively are connected to a low voltage and a preset voltage. A first terminal of the inductor is connected to the low voltage. Positive and negative terminals of the diode are respectively connected to a second terminal of the inductor and a high voltage. First and second terminals of the switch are respectively connected to the second terminal of the inductor and the preset voltage. The detection circuit detects the low voltage to thereby switch ON-OFF states of the switch in demand. Moreover, a LED illumination device using the current regulating circuit also is provided.

Abstract: A pixel includes: an organic light emitting diode; a first transistor having a second electrode connected with an anode electrode of the organic light emitting diode and controlling the amount of current supplied to the organic light emitting diode; a second transistor connected between a data line and a second node and turned on when a scan signal is supplied to a scan line; a third transistor connected between a gate electrode and a second electrode of the first transistor and having a turn-on time partially overlapping the turn-on time of the second transistor; a fifth transistor connected between the second node and a power line receiving first power and having a turn-on time not overlapping the turn-on time of the second transistor; and a storage capacitor connected between a gate electrode of the first transistor and the second node.

Abstract: A method of driving a display panel includes generating a gate on voltage, a first gate off voltage and a second gate off voltage. A clock signal is generated based upon the gate on voltage and the second gate off voltage. A first panel gate off voltage substantially the same as the first gate off voltage and a second panel gate off voltage substantially the same as the second gate off voltage are generated in a first operating mode. A first panel gate off voltage greater than the first gate off voltage and a second panel gate off voltage greater than the second gate off voltage are generated in a second operating mode. A gate signal is generated based upon the clock signal and the first and second panel gate off voltages to a gate line of the display panel.

Abstract: A pixel may include: an OLED; a first transistor having a first electrode connected to a power line receiving a first power, the first power changes to an initial voltage, a reference voltage, and a high voltage, the first transistor controlling the amount of current supplied to the OLED; a second transistor connected between a data line and a second node and turned on when a scan signal is supplied to a scan line; a third transistor connected between a gate electrode and a second electrode of the first transistor and having a turn-on time partially overlapping the turn-on time of the second transistor; a fourth transistor, connected between the second node and the power line, and having a turn-on time not overlapping the turn-on time of the second transistor; and a storage capacitor connected between the gate electrode of the first transistor and the second node.

Abstract: A light emitting element driver includes: a light emitting element; driving means; an electric accumulation element; and a battery power supply that can supply electric power to the driving means and the electric accumulation element, wherein the driving means is configured so as to be able to switch between a state in which the electric accumulation element accumulates the electric power supplied from the battery power supply and a state in which the electric accumulation element supplies the accumulated electric power to the light emitting element, the driving means connects the electric accumulation element and the light emitting element in parallel to each other with respect to the battery power supply when the electric accumulation element accumulates the electric power supplied from the battery power supply, and the driving means connects the battery power supply, the electric accumulation element, and the light emitting element in series when the electric accumulation element supplies the accumulated e

Abstract: A switched capacitor array having a plurality of capacitors arranged in a plurality of branches having different numbers of capacitors, and a plurality of switches connected to selectively couple the capacitors across the input or the output may be used for powering a variety of loads. A switched LED array may be dynamically configured based on a voltage supplied thereto, which may be supplied by a switched capacitor array. A lighting apparatus may be provided with first and second blocks, each block comprising a switched capacitor array, a switched LED array, and a control system.

Abstract: The dimming circuit includes a reference signal generation unit, a frequency modulation unit and a duty cycle control unit. The reference signal generation unit generates a reference signal. The frequency modulation unit generates a frequency modulation signal having an initial frequency based on the reference signal and a control signal, repeatedly performs a counting operation that counts at least one pulse of the frequency modulation signal, and adjusts the frequency of the frequency modulation signal if the counting operation is completed. The duty cycle control unit generates a pulse width modulation (PWM) output signal by adjusting a duty cycle of the frequency modulation signal.

Abstract: An LED drive circuit is provided that is connectable to a phase-control light controller and drives an LED load by use of a voltage obtained by rectifying a phase-controlled alternating current voltage inputted from the phase-control light controller. The LED drive circuit includes: a first phase angle detection portion that detects a phase angle in a present cycle; a second phase angle detection portion that detects a phase angle in a cycle preceding the present cycle by at least one cycle; a bias portion that generates a detection signal by adding a predetermined delay time to a phase angle obtained by averaging the phase angle detected by the first phase angle detection portion and the phase angle detected by the second phase angle detection portion; and a drive portion that starts current supply to the LED load at timing based on the detection signal generated by the bias portion.

Abstract: A first entity communicates with a second entity over a shared power bus by switching the bus to a high-impedance state and modifying the voltage on the power bus, in accordance with an outgoing communication, such that the modified voltage is detected by the second entity and the communication is received thereto.

Abstract: The amplitude of a potential of a signal line is decreased and a scan line driver circuit is prevented from being excessively loaded. A light-emitting device includes a light-emitting element; a first power supply line having a first potential; a second power supply line having a second potential; a first transistor for controlling a connection between the first power supply line and the light-emitting element; a second transistor, which is controlled in accordance with a video signal, whether outputting the second potential applied from the second power supply line or not; a switching element for selecting either the first potential applied from the first power supply line or the output of the second transistor; and a third transistor for selecting whether the first potential or the output of the second transistor which is selected by the switch is applied to a gate of the first transistor.

Abstract: Various embodiments relate to a circuit arrangement for operating at least one discharge lamp. In order to prevent intrinsic flicker at low dimming settings and low temperatures, according to various embodiments, a direct current which is fed into the discharge lamp so as to avoid striated discharges at relatively high dimming settings is reduced or entirely eliminated.

Abstract: An electro magnetic ballast (110) for a gas discharge lamp (2) comprises: input terminals (3), for receiving a mains voltage; lamp connector terminals (4), for receiving a lamp; a controllable semiconductor switch (26) coupled in parallel to the lamp connector terminals; a current sensor (127) connected in series with the controllable switch (26); and a control circuit (28) for controlling the controllable switch (26) and responsive to the current sensor (127). When operating in a normal mode, the control circuit (28) is responsive to a current sense signal received from the current sensor to switch the controllable switch (26) ON if said current sense signal indicates a current flowing in the controllable switch (26) and to switch the controllable switch (26) OFF if said current sense signal indicates that no current is flowing in the controllable switch (26).

Abstract: The invention relates to an electronic device for turning on a fluorescent lamp and a fluorescent lamp comprising said device, wherein said fluorescent lamp comprises a fluorescent tube (1) having an electrical terminal (2) at each end, and wherein said fluorescent lamp is connected in parallel with an electronic module (3) and a voltage source configured to supply said fluorescent lamp, said electronic module (3) being configured to turn on a burnt-out fluorescent lamp keeping it turned on until the end of its service life as its light intensity is reduced.

Abstract: The present disclosure thus provides a technique for providing multi-level operation of ballast circuitry for discharge lamps. In one version, an auxiliary capacitance is switched in and out of circuit by a user controlled switch for lower the frequency of the voltage from the inverter to the transformer resulting in lower power output to the lamps. In another version, the auxiliary capacitance may be switched in and out of circuit by a user operated switch wherein the capacitance is connected to the secondary or output winding of the transformer for selectively reducing power to the lamps for reduced illumination. In other versions, auxiliary inductances are selectively switched in and out of circuit to alter the frequency of the primary voltage to the transformer. In another version, an auxiliary winding is selectively switched in and out of the secondary of the transformer for providing normal and reduced level power to the lamps.

Abstract: An exemplary backlight control circuit includes a transformer, a control circuit, a lamp. The control circuit and the transformer form an inverter circuit to providing an alternating current (AC) voltage for driving the lamp. When the backlight control circuit works in a startup mode, the backlight control circuit defines a first current path including the lamp and the first current path forms a first resonant circuit. When the backlight control circuit works in an operation mode, the backlight control circuit defines a second current path including the lamp and the second current path forms a second resonant circuit. The first and second resonant circuits have different resonant frequencies from each other.

Abstract: A capacitor charging apparatus includes a transformer and an output capacitor charged with current flowing through a secondary coil of the transformer, and charges the output capacitor by performing a switching control of a switching transistor provided on a path leading to a primary coil of the transformer. A switching control unit controls on and off of the switching transistor. A voltage detector monitors a voltage at a tap provided in the secondary coil of the transformer. The switching control unit regards the voltage detected by the voltage detector as an output voltage of the capacitor charging apparatus, and controls the on and off of the switching transistor.

Abstract: An electronic ballast includes a step-up converter, which includes a storage inductor, a diode, an intermediate circuit condenser and a switch element. According to the invention, a current passing through the storage inductor is used in the form of an indicator of turnon and turnoff times of the step-up converter oscillates in a self-exciting manner.

Abstract: A lightweight, small, high-voltage power supply for a xenon flash lamp or strobe permits rapid and reliable strobing for retinal imaging. In one embodiment the power supply can develop 500 volts at 720 watt seconds to permit firing the xenon strobe at full power one pulse per second. The power supply, rather than using heavy, bulky transformers, uses a hybrid high-voltage multiplier that involves an AC coupling circuit and a half-wave rectifier, the outputs of which are coupled in series to a capacitor bank to achieve a 500-volt charging source for the capacitor bank. This permits the capacitor bank to be charged with a continuous high voltage so that it can deliver a controlled, reliable high voltage to the xenon strobe.

Abstract: An electronic ballast circuit for a lamp is described, wherein the ballast comprises a power factor correction circuit coupled to an inverter circuit. The inverter circuit is further coupled to a trigger circuit, which is in turn operatively connected to a hot or neutral line of a power supply by a control line. Upon closing a switch in the control line, the trigger circuit operates to place a capacitor in parallel with a base drive winding of a transistor in the inverter circuit, causing the inverter circuit to shut down. When the switch is opened, the trigger circuit shuts off and the inverter starts up and returns to an oscillating state.

Abstract: Optical element driving circuits flexibly configure energy sources to cause a flash tube to produce illumination at one of multiple output intensities. The driving circuits allow a single strobe alarm to take the place of multiple strobe alarms individually dedicated to specific output intensities. The driving circuits may also mitigate or eliminate high voltage arcing within the driving circuit.

Abstract: The continuity of a series-wired, lamp circuit is restored after interruption caused by failure of a lamp filament by providing a control relay that is wired in parallel with each lamp. A power resistor having a resistive load substantially the same as that of a lamp filament is arranged in series with the relay contacts, which are normally open. The failure of a lamp filament causes a high voltage to be impressed across the coil of the relay, causing it to pick up and its contacts to close, thus substituting the resistor for the lamp filament and restoring continuity to the circuit.

Abstract: In a discharge lamp lighting apparatus to light two discharge lamps, one terminal of the secondary side of a step-up transformer is connected to one terminal of each of the two discharge lamps, the other terminal of each of the two discharge lamps is connected, via each of two variable inductance elements, to one lamp current detecting unit, a signal of each lamp current detecting unit is connected to a lamp current control circuit, and an output signal from each lamp current control circuit is connected to each variable inductance element so as to vary the inductance of each variable inductance element, whereby the lamp current flowing through each discharge lamp is controlled.