Abstract: A power supply circuit for a cold-cathode fluorescent lamp (CCFL). The power supply circuit converts a DC voltage to a high AC voltage for driving the CCFL. The power supply circuit includes: a switch; a switch control circuit for controlling the switch; a transformer for stepping up the voltage; an energy-preserving unit coupled to the transformer and the DC voltage output circuit; a first diode coupled to the transformer, the energy-preserving unit, and the switch; and a decoupling capacitor coupled to the transformer for outputting the high AC voltage.

Abstract: A discharge lamp lighting device having: a power control circuit for controlling power to be supplied to a discharge lamp; an AC converter circuit provided between the power control circuit and the discharge lamp for converting a DC current into an AC current; a timer circuit for controlling operation of the AC converter circuit; and an igniter circuit for generating a high voltage pulse to thereby activate the discharge lamp; wherein the timer circuit includes: a second timer for starting as a timer in accordance with a power supply activating signal; a first timer for starting as a timer in accordance with lighting of the discharge lamp; and an OR circuit for outputs of the first and second timers. Thus, the DC lighting time is designed to be not changed and stable lighting can be achieved.

Abstract: The invention relates to a novel operating circuit for a low-pressure discharge lamp 1 with early EOL detection via a measurement of the DC voltage between the electrodes 2, 3. In this case, an electrode interrogation can be carried out by checking a respective connection via the electrodes 2, 3 to a respective reference potential.

Abstract: A light-weight, portable photocuring device possesses a single light emitting diode (LED). The single LED backed with a heat sink is driven by a driving circuit and controlled by a timing circuit. A temperature monitor can be included in a closed loop to feed back and control the driver. Lenses and/or light guides in the device act to further direct the light.

Abstract: The present invention comprises a unique starter assembly for a gas discharge lamp. The starter assembly comprises a main current path with a first leg connected to one electrode of a gas discharge lamp, and a second leg connected to a second electrode of the gas discharge lamp. A starting current path is provided between the first and second electrode, and comprises an magnetic switch. The magnetic switch is actuated by an electromagnet controlled by a control circuit. The control unit may be programmed with the start time required for a particular lamp design. In an alternative embodiment, the starter assembly further comprises a radio frequency identification system. The radio frequency identification system includes a gas discharge lamp transponder. The lamp transponder is used to communicate specific lamp information to the control circuit. The control circuit may then modify the start time for that lamp based on this information.

Abstract: A transformerless, microprocessor controlled xenon power supply including: a DC supply which rectifies and filters the incoming AC electrical power; a plurality of current path connected between the DC supply and a xenon bulb, each current path having an input for receiving power from the DC supply, an inductor and a controllable switch for controlling the flow of electrical current to the bulb; and an output for driving the xenon bulb. Each controllable switch includes a switch input connected to the output of a pulse width modulator for controlling the flow of electrical current through the controllable switch in a binary fashion. Preferably, the output voltage and current are measured and used to control the pulse width modulator such that, prior to ignition of the bulb, the output is regulated at a substantially constant voltage. After ignition of the bulb, the output is regulated at a substantially constant power.

Abstract: A light source device in which a discharge lamp, which contains greater than or equal to 0.15 mg mercury per cubic millimeter of the volume of the discharge space, and in which there is a pair of electrodes disposed opposite one another, is connected to a feed device (Ex). The feed device is used to start the discharge lamp and to supply the discharge current to the electrodes. The feed device (Ex) serves an identification function identifying a discharge state of the discharge lamp as a glow discharge state. Further, during the identification of the glow discharge state, the electric power supplied to the discharge lamp is set at less than or equal to twice as high as the nominal electric power of the above described discharge lamp to eliminate the formation of blackening on the inside of the bulb glass during glow discharge.

Abstract: A ballast circuit is provided, comprising: a plurality of inverters, each inverter for powering a load; and a controller operationally coupled to a shutdown control signal of each inverter for selectively shutting down any combination of inverters. In another aspect, the controller is for selectively disabling any combination of inverters to effectively disconnect the load associated with each disabled inverter. The controller is for receiving communications from a control device, each communication a selection of 0%, “n−1” approximate percentages each associated with a ratio of “1” through “n−1” loads to “n” loads, where “n” is the total number of loads powered by the inverters of the ballast circuit and where the numerator for each ratio is an integer between “1” and “n−1,” inclusive, or 100% light from the combined loads powered by the inverters of the ballast circuit.

Abstract: A filament cut-back circuit is disclosed. The filament cut-back circuit comprises an impedance circuit coupled in series between either an AC voltage source and a primary filament winding, or a secondary filament winding and a filament. In response to an alternating voltage from the AC voltage source when coupled in series thereto or an alternating voltage from the secondary filament winding when coupled in series thereto, the impedance circuit operates as a short circuit when the alternating voltage is at a preheat frequency and operates as an open circuit when the alternating voltage is at an operating frequency.

Abstract: A photo diode lamp includes lamp head, receiving body, outer shell, cover and photo sensor. There are projections and indents provided on the inner circumference of the receiving body, which receives base and circuit block. The lamp-tube is fixed on the base, its circumference provides screw thread and wire opening. The photo sensor is provided from the end of the wire, the respective projections are provided at lower end of its screw thread. The base of the circuit block is the circuit of the energy-saving type lamps and lanterns, the photocell is provided thereon through an IC. The end with larger diameter of the outer shell provides inner screw thread. Between the outer shell and the cover is clipping connection. The circuit is controlled by means of photo sensor responding to the brightness of outer circumference the lamps and lanterns can be automatically in switch-on/switch-off state.

Abstract: A ballast circuit is provided having an input, an output for coupling to an electric discharge lamp and an oscillation circuit for illuminating the lamp. A circuit may be included for sensing when a voltage on an input to the oscillation circuit exceeds desired levels. The ballast circuit may be shut down, limited or otherwise controlled to reduce the possibility of ballast failure.

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: An electronic ballast for at least one gas discharge lamp (LA) comprises a rectifier circuit (2) connectable to an a.c. voltage source (U0), a smoothing circuit (3), connected to the output of the rectifier circuit (2), for generating an intermediate circuit voltage (Uz), and an inverter (4) fed with the intermediate circuit voltage (Uz), at the output of which inverter a connection for the load circuit (5) containing the lamp (LA) is connected. The smoothing circuit (3) is constituted by a switching regulator and the ballast further has a control circuit (6) which detects the intermediate circuit voltage (Uz) and controls a controllable switch (S1) of the switching regulator in dependence upon the value of the intermediate circuit voltage (Uz).

Abstract: A method and apparatus for driving a ballast in critical discontinuous mode (CDCM). The method provides for zero loss switching in order to maximize efficiency, and also provides controllable input and output power without the use of complex and costly feedback loops.

Abstract: Disconnection device for an electronic operating device for gas discharge lamps. The DC component is evaluated at a coupling capacitor (C5) specifically via a filament. Disconnection is performed in the event of filament breakage. In addition, the AC component of the generator output (O) can be monitored via a second filament, and disconnection can therefore also be performed in the event of breakage of the second filament.

Abstract: A ballast (10) for powering a gas discharge lamp load includes an inverter (200) and a protection circuit (400) for preventing startup of the inverter (200) in response to a ground fault condition wherein one or more of the ballast output connections (302,306) is coupled to earth ground.

Abstract: A ballast (10,20) for powering a gas discharge lamp load (30) comprises a protection circuit (300,600) operable to monitor an electrical signal (40) in the ballast and disable the ballast for at least a predetermined period of time in response to a disturbance wherein at least a portion (44) of the electrical signal (40) exhibits a time-rate-of-change that exceeds the time-rate-of-change of the signal during normal operation of the ballast and gas discharge lamp load. Protection circuit (300,600) is capable of disabling the ballast within a response time that is less than twice the period of the electrical signal. In a preferred embodiment that is suitable for ballasts with driven-type inverters, protection circuit (300) comprises a latching device (310) and a triggering circuit (330). In a preferred embodiment that is suitable for ballasts with self-oscillating type inverters, protection circuit (600) comprises a pull-down circuit (640) and a negative voltage source (610).

Abstract: The present invention relates to a device for preheating the two coil electrodes (W1, W2) of a fluorescent lamp (La) comprising an AC voltage source (10), a resonance capacitor CR, which is arranged serially between the two coil electrodes (W1, W2), a first inductance (L1), which is coupled between the AC voltage source (10) and one of the two coil electrodes (W1, W2), and a second inductance (L2), which is connected to a point between the AC voltage source (10) and the coil electrode (W1) coupled thereto, the second inductance (L2) being coupled to the first inductance (L1) in such a way that a current flow (IL2) through the second inductance (L2) leads to a reduction of the magnetization of the first inductance (L1). It furthermore relates to a corresponding method.

Abstract: A hand-held fluorescent lamp assembly powered by typical line supply of 120 VAC, 60 Hz via an attached power cord and employing multiple commonly available fluorescent lamps. The assembly includes switches to independently control the multiple fluorescent lamps. The assembly includes lightweight solid state power regulation components. The power regulation circuit employs a self-oscillating circuit that is approximately matched in frequency of oscillation to the natural frequency of the fluorescent lamp load to automatically ignite the fluorescent lamps. The power regulation circuit includes circuit elements to automatically protect the ballast circuit and lamps from overdrawing in the run state and from abnormal load conditions.

Abstract: An electronic ballast for lamps or tubes is provided. In one embodiment the present invention includes a ballast controller that includes filament heating circuitry and dimming circuitry. The filament heating circuitry may include preheat dimming circuits which preheat the filaments for a predetermined time period prior to striking the lamp, and steady-state heating circuitry that continually heats the filaments during steady state operation of the lamp. The steady state heating circuitry may be adapted to heat the filaments inversely proportional to the dim desired value of the lamp. The dimming circuitry may include conventional analog dimming and/or burst mode dimming to define a wide range of dimming characteristics for the lamp.

Abstract: The invention relates to a circuit arrangement for operating electric lamps, the circuit arrangement having an inverter for generating a medium or high-frequency supply voltage for one or more lamps (21) and a starting circuit for the inverter, and also a device for deactivating the starting circuit, the starting circuit comprising a voltage-dependent switching element (34) and a capacitor (33), and the device for deactivating the starting circuit comprising a switching means (35) whose switching path is arranged in parallel with the capacitor (33) of the starting circuit. According to the invention, the device for deactivating the starting circuit has a threshold switch (39) for controlling the switching means (35).

Abstract: A self-oscillating boost converter includes a resistor-starting network configured to start a charging of the boost converter. A resonant feedback circuit is designed to generate an oscillating signal following the starting of the circuit by the resistor-starting network. A complementary switching network has a pair of complementary common-source connected switches configured to receive the oscillation signal generated by the resonant feedback circuit. The oscillation signal determines a switching rate, or duty cycle, of the complementary pair of switches. A boost inductor is in operational connection with the complementary pair of switches. The switching rate of the complementary switching network acts to determine the boost voltage supplied to a load.

Abstract: In a discharge lamp lighting apparatus 1, power is supplied from a DC power supply 2 through a switch control circuit 3 to a lighting circuit 4 and a discharge lamp 5. Power is supplied to the lighting circuit through a semiconductor switch element 11 placed in a switch control circuit 8 and a part of the current flowing into a semiconductor switch element 12 is detected and is compared with reference values in comparators 21 and 22, thereby detecting an anomaly in the lighting circuit or the discharge lamp.

Abstract: A ballast (10) for powering a gas discharge lamp includes a lamp-out detection circuit (300) that quickly responds to a lamp-out condition. Lamp-out detection circuit (300) receives a portion of the lamp current and provides a detection voltage. The detection voltage remains at a first average level while the lamp is conducting current in a normal manner, but quickly decreases below a second level if the lamp ceases to conduct current. In a preferred embodiment, ballast (10) includes an inverter (100) and a resonant circuit (210,220) that are normally operated at a high frequency. The detection voltage is coupled to an enable input (112) of an inverter drive circuit (110), and the inverter (100) is either shut off or operated in a low-power mode within less than ten high frequency cycles after occurrence of a lamp-out condition.

Abstract: Gas discharge tube displays according to the present invention control power applied to the tubes using isolator/switches, which can be opto-isolators in combination with triacs, FET's or other semiconductor switching devices or devices which can form part of a switching circuit. Such displays can also use, if desired and if appropriate, isolators which also act as the switch without other switching devices or circuits to switch and otherwise control activation of the tubes on the secondary side, or high voltage side, of the power source or sources feeding the tubes. They may also use such switching devices or circuits which act as both the isolator and the switch. The opto-isolators separate or isolate the low voltage control circuitry from the high voltage tube power circuitry, in conjunction with a triac, FET, thyristor or other device, preferably a semiconductor device, that is adapted to withstand the power load yet accomplish the switching necessary to control activation of the tube in real time.

Abstract: A light source device with a mercury lamp, in the case of formation of a bridging short circuit of the gap between the electrodes of the discharge lamp caused by mercury, to prevent the light source device from no longer being usable because the difference between a defective device and one with such a bridging short circuit cannot be ascertained, has a means for determining that a bridging short circuit has formed in the gap between the electrodes. Furthermore, various manners for eliminating the bridging short circuit are provided including those that make use of vibration, heat, dielectric discharge or Lorenz forces.

Abstract: An improved ignition circuit for a high intensity discharge (HID) lamp is disclosed. The ignition voltage is provided across a single capacitor, and at the end of the ignition phase, a second capacitor is switched into the circuit to divide the voltage across two capacitors, and provide a steady state square wave current and voltage.

Abstract: A discharge lamp operating apparatus includes a discharge lamp and a driving circuit of the discharge lamp. The driving circuit can vary power to be supplied to the discharge lamp and has a function to turn off the discharge lamp at a supplied power value above a supplied power value at which unstable discharge occurs in the discharge lamp.

Abstract: A ballast (10) for powering a gas discharge lamp (20) having heatable filaments (22,24) includes a filament heating and protection circuit (300) that provides preheating of the filaments, efficiently reduces the filament heating power after the lamp ignites, quickly responds to removal or failure of the lamp in order minimize power dissipation in the ballast, and operates a replaced lamp without requiring cycling of the power to the ballast. In a preferred embodiment, filament heating and protection circuit (300) includes a transformer (400), a switching circuit (600), a turn-on circuit (700), and a lamp-out detection circuit (800).

Abstract: In a piezoelectric transformer control circuit, when a load (2) is disconnected from a piezoelectric transformer (1) and changes to an open state, an output detection voltage (Vdet) becomes higher than a reference voltage (Vref2), and the output from a voltage comparator (10a) goes “Low”. When the output of the piezoelectric transformer (1) is short-circuited to GND, the output detection voltage (Vdet) abruptly drops to almost “0” and becomes lower than a reference voltage (Vref3). The output from a voltage comparator (10b) goes “Low”. A voltage-controlled oscillation circuit (6) detects the signal “Low” to stop the generation of the oscillation signal to a driving circuit (7) for driving the piezoelectric transformer (1).

Abstract: Electronic system for generating and controlling light effects on projectors utilizing arc lamps, composed of an electronic power unit provided with a transformer fed via transistors, the secondary circuit of the transformer being connected to the feed terminals of the lamp, within the secondary circuit of the transformer there being connected a component for withdrawing a proportion of the instantaneous current circulating through the secondary circuit to produce an electrical signal which is made available to a control block which also receives an electrical reference signal generated by a pulse generator, the control block being arranged to compare the two electrical signals and to set the transistors to a conducting or inhibiting state depending on the result of the comparison, the amplitude and frequency of the electrical reference signal being adjustable by the operator.

Abstract: A liquid crystal projector comprises a reset switch for resetting the operation of a microcomputer, and abnormality recovery means for initializing, when the liquid crystal projector is in a power on mode, other circuits and the microcomputer without stopping a projecting lamp and a cooling fan when the reset switch is turned on.

Abstract: A gas discharge lamp lighting device includes a DC/DC converter for adjusting electric power supplied from a power supply to generate and output a DC voltage, and an FET electrically connected to the DC/DC converter, for converting the DC voltage from the DC/DC converter to an AC voltage to be supplied to a gas discharge lamp. A control unit brings the gas discharge lamp to an electrode heating state in which both electrodes of the gas discharge lamp are heated after supplying the AC voltage to the gas discharge lamp. The control unit controls energy supplied to the gas discharge lamp in the electrode heating state according to a voltage across the gas discharge lamp. The control unit brings the gas discharge lamp to an AC discharging state in which an AC current flows through the gas discharge lamp after the energy has been supplied to the gas discharge lamp.

Abstract: A method and a device for power management regarding an integrated display unit including a video display and at least one peripheral device, wherein the video display uses horizontal and vertical sync signals for the synchronization of the display images, and the peripheral device uses a peripheral signal to carry out its function. The peripheral device can be an audio unit using audio signals to produce sound. The peripheral device can be a USB connector using a +5 V voltage to indicate a connection being made to the integrated display unit. In the integrated display unit, a single power supply is used to provide electrical power to the video display and the peripheral device. In order to reduce the power consumption by the integrated display unit, a number of power consumption states, based on the presence of the video sync signals and the peripheral signals, are implemented. The presence of the video sync signals can be detected by a micro-controller in the integrated display unit.

Abstract: A portable image projector is provided with a fan having a control system for cooling a metal-halide arc lamp. The arc lamp cooling system of the present invention includes a fan having a fan control to operate the fan at an initially reduced level during lamp start-up to allow the temperature of the arc lamp to increase to its full operating temperature. The fan control includes a microcontroller to operate the fan at a reduced voltage over a period of time after which the voltage is increased to operate the fan at full capacity. Power to the fan may be increased in incremental time steps or linearly over a period of time as determined by the microcontroller.

Abstract: A discharge lamp lighting circuit is provided with a DC power source circuit, a DC-AC conversion circuit, and start circuits. A primary circuit of a transformer in each start circuit has a capacitor and a switch element. When the voltage across the capacitor exceeds a threshold value, or when the switch element has electrical continuity, a high voltage is supplied separately to the discharge lamps from the primary coil through the secondary coil. A common voltage supply circuit supplies the voltage to the primary circuit of each start circuit from the DC power source circuit or the DC-AC conversion circuit.

Abstract: High voltage and low voltage switch mode circuits and methods serve to recover the charge stored on electro-luminescent lamp panels that would otherwise be dissipated during the discharge cycle of a drive circuit. The high voltage circuits and methods operate to transfer the charge to the high voltage rail, while the low voltage circuits and methods operate to transfer the charge to the source of low drive voltage.

Abstract: An abnormality detection circuit 22 delivers a detected abnormality relating to a transformer 11. An interrupter circuit 23 turns a switch 16 off to interrupt the supply of the power to the transformer 11. When the supply of the power is interrupted, the switch 16 is connected to a restart circuit 31, whereupon the circuit 31 is activated to allow a charging current to flow to a capacitor, which is connected in series in a drive current path of a drive circuit 32 with a time delay on the order of 0.5 to 1.0 second which is determined by a delay circuit thereof. The charging current drives a restoring circuit 33, which controls the interrupter circuit 23 so that the switch 16 is turned on.

Abstract: A power supply apparatus includes a direct current power source having a pair of terminals. First and second switching elements are connected in series between the pair of terminals of the direct current power. A load circuit, which includes a resonance inductance and a resonance capacitance, receives a high-frequency alternating current generated by a switching of the first and second switching elements. An unsaturated transformer has a first winding connected to the load circuit, and a second winding generating an induced voltage in proportion to a current flowing in the load circuit. A drive resonance circuit includes a capacitance, and an inductance of the second winding. The drive resonance circuit produces a resonance output to cause the first and second switching elements to alternately conduct. The power supply may be used in a ballast for a discharge lamp.

Abstract: A circuit for receiving electrical power from a switched source such as a solid state relay, and providing power to a semiconductor light source. A rectifier circuit and an interference filter are connected in series between input connections which are connected to the switched source, and a converter which provides the required voltage and current combination for the light source. To prevent improper operation of the switched source, such as oscillation, the portion of the circuit between the input terminals and the rectifier circuit is free from capacitive elements. Preferably the interference filter is connected between the rectifier and the converter. The light source may be used as a signal light, and the circuit may be incorporated in the housing of the signal light.

Abstract: A system for operating a discharge lamp at partial power by heating the filaments to maintain an operating temperature for the filaments within an operating temperature range. The system comprises a ballast with a resonant circuit having a resonant frequency for supplying power to the discharge lamp and a heating power to each filament of the discharge lamp. The heating power is substantially controlled by an inductor in series with each filament. The ballast with the discharge lamp as a load is characterized by an output having a higher voltage at lower power than at higher power levels. This profile is also suitable for heating the filaments of the discharge lamp, which require more heating power or higher voltage when the discharge lamp is operating at lower power levels.

Abstract: In an electronic ballast equipped with a digital lamp power control loop, the gain is controlled in dependence on the signs of consecutive error signals and the absolute values of these signals. The digital control loop is stable and comparatively fast for a wide range of values of the power consumed by the lamp.

Abstract: A high-intensity discharge lamp includes an arc tube having a pair of main electrodes, a starting circuit having a thermally-actuated switch for disconnecting the starting circuit, and an outer tube for containing the arc tube and the starting circuit, and the lamp is lighted by means of a reactance ballast. The thermally-actuated switch includes an envelope bulb that covers contacts of the thermally-actuated switch. Thereby, occurrence of sustained arc discharge in the outer tube is prevented in the case of a starting failure or a break-off of the arc tube at the end of the lamp's life.

Abstract: A switching arrangement intended to operate a high-pressure discharge lamp at a voltage having successive periods of opposite polarity.

Abstract: An ignitor disabling apparatus is provided to reliably and automatically disable a universal sodium ignitor with hot re-strike capability, or a 120 Hz pulse capability. The ignitor is configured to disable the ignitor portion of a HID lamp if the lamp fails to start. Timing operation of the disabling circuit is achieved using a power supply that ramps to a steady state to provide triggering of a timer circuit. A normally closed, solid state gating device is used for disabling the ignitor to minimize sparks. The disabling apparatus can be retrofit into an existing universal sodium ignitor.

Abstract: An electronic ballast for igniting a discharge arc in a discharge tube of a ceramic metal halide lamp. The ballast includes ballast circuitry for periodically applying a voltage pulse having an amplitude of approximately 2-3 kilovolts to the discharge tube until ignition of the discharge arc is achieved. Each voltage pulse consists of a voltage pulse train having a frequency exceeding the acoustic resonance range of the discharge tube, preferably in a range of 2.5-3.0 megaHertz. A hot restart protection circuit of the ballast circuitry provides that the time period between voltage pulses is sufficient to permit cooling of the discharge tube during a time interval spanning application of a plurality of voltage pulses.

Abstract: Process for the recognition of the rectifier effect appearing in a gas discharge lamp (G1, G2) and an electronic ballast, for the operation of gas discharge lamps (G1, G2), with which such a process finds employment. The electronic ballast includes a monitoring or control circuit (IC2) which monitors an operating parameter of a load circuit (E) of the electronic ballast, whereby this operating parameter corresponds to the lamp voltage or is dependent thereon. The monitoring circuit (IC2) integrates this monitored operating parameter over a full period and determines upon the presence of a rectifier effect if the integration result deviates from a predetermined integration desired value. Further, for the recognition of the rectifier effect, the duration of the positive and negative half-waves of the monitored parameter can be compared.

Abstract: An electronic operating device for discharge lamps is disclosed in which an output terminal is connected via a coupling capacitor (CB) to a reference potential (E). An electric component (VC) which acts as a voltage source is inserted in series with the coupling capacitor (CB) in order to reduce the potential of an output terminal. The electric component (VC) consists in one embodiment of an inductor which is coupled to the lamp inductor.

Abstract: To prevent inadvertent illumination of a light emitting diode (or set of light emitting diodes) by stray currents at extremely low levels, a quiescent current limiting resistive load is connected in parallel with the light emitting diode, sized to conduct a desired minimum current at the lowest forward voltage drop at which the light emitting diode is expected to properly illuminate. Rather than connecting the resistive load across the input/output ports of the driver circuit, in parallel with any biasing resistance and the light emitting diode, the load is connected directly in parallel with the light emitting diode. Additional current through the quiescent current limiting resistive load as the voltage across the input/output ports increase is thus effectively capped by the maximum forward voltage drop across the light emitting diodes.

Abstract: A gas discharge lamp including a power supply connectable to a load, and an overvoltage-protection-and-ground-fault-interrupt (OVP/GFI) circuit interconnected with the power supply. The OVP/GFI circuit includes an overvoltage-protection (OVP) sub-circuit that deactivates the power supply when an overvoltage condition is detected, and a ground-fault-interrupt (GFI) sub-circuit that deactivates the power supply when a ground-fault condition is detected.