Abstract: A ballast protecting device is connected between an AC input voltage and a ballasted lamp. The device includes a voltage sensing block, a current sensing block, a pulse forming block, a switch block, and a micro-controller unit (MCU). The pulse forming block converts positive half cycles of the voltage and current provided by the voltage and current sensing blocks to square wave pulses, and the MCU performs a phase angle comparison between generated pulses. Upon lamp malfunction, ballast current is phase shifted. Current may also be phase shifted when there is a radical change in the input voltage. As a trend of the phase shift between current and voltage is determined by the MCU, a ballast disconnect decision is made, and the MCU actuates the switch block to disconnect the connected ballast and malfunctioning lamp.

Abstract: A cold cathode fluorescent lamp controller constituted of a pulse generator exhibiting a cycle period; a burst dimming control operative to set a burst dimming duty cycle for the pulse generator; a comparator arranged to receive a signal indicative of the value of current through a load driven by the pulse generator and compare the received signal to a reference signal; an error detection circuit operative to shut down the pulse generator responsive to an output of the comparator indicating that the received signal is less than the reference signal for a predetermined number of cycles of the pulse generator; and a disable circuit arranged to prevent, when the set burst dimming duty cycle is less than a predetermined value, the shut down of the pulse generator responsive to the output of the comparator indicating the received signal is less than the reference signal.

Abstract: A light emitting driver circuit, system, and method are provided. The driver circuit system and method can be implemented in various ways. An embodiment includes a bypass circuit which diverts current from the LEDs whenever a switch coupled to the LEDs incurs residual current when turned off. In an additional or alternative embodiment, the residual current can be sensed and the amount of residual current used to trigger fetching of a compensation value. That compensation value can change a dimming function forwarded to the switch in order to compensate for, offset, or substantially eliminate the residual current through that switch.

Abstract: An LED driving circuit is provided for making it possible to economically drive a serially connected LED circuit by means of a switching device with a relatively low withstanding voltage even if the number of serially connected LED devices increases. In an LED driving circuit provided with a serially connected LED circuit (11) in which many LED devices are serially connected and a switching device (13) serially connected with the serially connected LED circuit (11) to control that an electrical current flowing through the serially connected LED circuit (11) is turned on or off, wherein a circuit device (15), which comprises a resistor, a constant voltage diode, a constant current diode, or the like, is connected in parallel with the switching device to make a minute current flow through the serially connected LED circuit (11) to the extent that the LED devices are not turned on when the switching device is turned off.

Abstract: A circuit arrangement for operating a discharge lamp (LA) with preheatable electrodes comprising: an input terminal for applying an input voltage (UE); an output terminal for providing an output voltage (UA) to a lamp generator (LG) for operating the discharge lamp (LA); a switching unit (14) for power factor correction which is coupled between the input terminal and the output terminal; a monitoring apparatus (20) which is adapted to switch off the lamp generator (LG) in the event of the presence of at least one switch-off criterion; an integrated circuit (16), which is adapted to drive the switching unit (14) for power factor correction, the integrated circuit (16) having a disable input; and a blocking apparatus (18), which is adapted to generate a blocking signal at its output when the lamp generator (LG) is switched off, the output of the blocking apparatus (18) being coupled to the disable input of the integrated circuit (16).

Abstract: A searchlight (3) on board a vessel (1) arranged for illuminating a point (2p) and maintain said point (2p) illuminated regardless of the movements of said vessel (1).

Abstract: A portable rechargeable electronic device, such as a flashlight, with external charging contacts and a short protection circuit is disclosed. The short protection circuit electrically uncouples one of the exposed charging contacts from the rechargeable power supply for the device when the charging contacts are short circuited. The charging contact is uncoupled without opening the power circuit for the device; thus, the device can continue to operate while the charging contacts are shorted. The power supply for the device may be a rechargeable lithium-ion battery pack.

Abstract: A lamp overload detection/modulation circuit including a microcontroller unit for detecting rectangular wave signal reflective of the power used by the lamp load and pulse width signal of AC power. The positive bandwidths of the two signals are compared with a predetermined full-load value. In the case that the positive bandwidths of the two signals are both larger than the full-load value, it is indicated that the lamp load is under an overload condition. Under such circumstance, the microcontroller unit controls a lamp load driving unit to change driving manner and lower the power used by the lamp load to a value within a nominal range. Then the lamp load automatically restores to the full-load state. Accordingly, the lamp is protected from long-term overload condition.

Abstract: A method for controlling a lamp circuit that includes: setting a first voltage threshold and a first time window within a control circuit corresponding to a characteristic of a first lamp type; providing a first signal through the lamp circuit to start a first time interval and create a first test voltage; comparing the first test voltage to the first voltage threshold; and operating a switch to couple an output of the lamp circuit to a source of electrical power if the first test voltage is greater than or equal to the first voltage threshold before the first time interval exceeds the first time window.

Abstract: An inverter circuit drives a light source module. An input signal circuit provides electrical signals. A power stage circuit converts the electrical signals to square-wave signals. A transformer circuit converts the square-wave signals to alternating current (AC) signals capable of powering the light source module. A voltage detection circuit detects voltage applied on the light source module so as to output a detected voltage signal. A feedback circuit feeds current flowing through the light source module so as to output a current feedback signal. A protection circuit is connected to the voltage detection circuit and the feedback circuit, for outputting a latch signal according to the detected voltage signal or the current feedback signal. A pulse-width modulation control circuit outputs a switch signal to the power stage circuit according to the latch signal. The input signal circuit also provides the electrical signals to the protection circuit.

Abstract: A transformer 6 and a photocoupler 5 are provided to ensure insulation between a primary side circuit section 10 connected to an alternating current power supply 2, and a secondary side circuit section 20 for applying a voltage to a lamp 4. A detection circuit section 22E, provided in the secondary side circuit section 20, detects an output voltage and an output current of the lamp 4 to detect a deviation from a predetermined power. A signal corresponding to the deviation, which has been detected by the detection circuit section 22E, is transmitted to the primary side circuit section 10 via the photocoupler 5 provided between the primary side circuit section 10 and the secondary side circuit section 20. A switching control section 13, provided in the primary side circuit section 10, carries out switching control for constant power lighting based on the signal transmitted from the photocoupler 5.

Abstract: A shut-down circuit configured for use with an electronic ballast coupled to a lamp in a control path includes a device for sensing the electrical energy associated with the control path, and a sensing circuit for shutting down the ballast in the event that the energy does not conform to a predetermined condition. The sensed energy may be current indicative of lamp installation or short circuit, or voltage indicative of arcing or open circuit. The device for sensing the electrical energy associated with the control path may be an isolation transformer, or alternative devices such as optical isolators may be employed. The circuitry may further include electronic componentry to disable the sensing circuit during initial energization of the lamp.

Abstract: Circuit with a switch-off device for the operation of light sources The invention relates to a circuit with a switch-off device for the operation of light sources (Lp), have the following features: a self-commutated half-bridge inverter having a series circuit of an upper electronic switch and a lower electronic switch (T1, T2), which are joined at a half-bridge midpoint (M) and are connected between a supply voltage (+) and a ground potential, a start capacitor (C3) which is joined via a trigger element (DIAC) to a control electrode of the lower electronic switch (T2), and a switch-off device having an input (E) and an output, which are configured and connected so that they discharge the start capacitor (C3) if a switch-off signal is applied to the input (E). The switch-off device contains a time delay.

Abstract: The present invention discloses a protection device for a discharge lamp inverter, which is electrically coupled to an inverter outputting at least two opposite-phase powers to drive at least one discharge lamp via at least two power cables. The protection circuit of the present invention comprises the following components: at least two voltage-division units, a detection unit, and a trigger unit. The two voltage-division units are correspondingly electrically coupled to the power cables to obtain the opposite-phase powers and are connected in series at a connection point in the other ends thereof. The detection unit detects the voltage variation of the connection point of the voltage-division units and then generates an abnormal signal. The trigger unit receives the abnormal signal and outputs a protection signal to the inverter to stop outputting power to the discharge lamp.

Abstract: A load driving circuit in which a load is connected to the connecting point of transistors as low-side and high-side main switch elements that have a totem pole structure and are connected between a pair of drive voltage supply lines. A protection circuit section is provided for the high-side transistor. In the protection circuit section, a resistor as a voltage control element is provided for a MOSFET as an overvoltage prevention switch and a capacitor is connected between the gate and the drain of the MOSFET.

Abstract: A shut-down circuit configured for use with an electronic ballast coupled to a lamp in a control path includes a device for sensing the electrical energy associated with the control path, and a sensing circuit for shutting down the ballast in the event that the energy does not conform to a predetermined condition. The sensed energy may be current indicative of lamp installation or removal, or voltage indicative of arcing. The device for sensing the electrical energy associated with the control path may be an isolation transformer or alternative devices such as optical isolators may be employed. The circuitry may further include electronic componentry to disable the sensing circuit during initial energization of the lamp.

Abstract: A LED-based lamp apparatus includes a LED unit having multiple LEDs connected in series, a step-up circuit for stepping up a power supply voltage by a switching action of a switching element to supply an electric current to the LED unit, a sensing element for measuring a value of the current, and a controlling element connected in series with the LED unit to control the current based on the measured current value. When some of the LEDs of the LED unit are broken and short-circuited due to, for example, long-term use, the current increases instantaneously and an overcurrent condition occurs. In this case, the controlling element limits the current immediately to correct the overcurrent condition. Thus, the controlling element prevents the overcurrent condition from causing a secondary failure to normal LEDs of the LED unit.

Abstract: An illumination source includes a plurality of LEDs, and an electrical circuit that selectively applies power from the DC voltage source to the LED units, wherein the illumination source is suitable for handheld portable operation. In some embodiments, the electrical circuit further includes a control circuit for driving the LEDs with electrical pulses at a frequency high enough that light produced has an appearance to a human user of being continuous rather than pulsed, the control circuit changing a pulse characteristic to adjust a proportion of light output having the first characteristic color spectrum output to that having the second characteristic color spectrum output. Some embodiments provide an illumination source including a housing including one or more LEDs; and a control circuit that selectively applies power from a source of electric power to the LEDs, thus controlling a light output color spectrum of the LEDs.

Abstract: An electronic ballast for a lamp has a DC voltage connection; a switching unit having a supply voltage with the DC voltage connection being coupled thereto, and a first capacitor coupled between the supply voltage connection and a reference potential; an AC voltage connection, at which a voltage can be made available which has at least one AC component. The series circuit includes a first nonreactive resistor and a first diode, as a second nonreactive resistor coupled between the AC voltage connection and the supply voltage connection, a connection point between the first diode and the second nonreactive resistor, and a second capacitor coupled between the connection point and the reference potential. The first capacitor and the second nonreactive resistor are dimensioned such that the average voltage drop across the second nonreactive resistor is greater than or equal to the average voltage drop across the first capacitor.

Abstract: A ballast (20) for powering one or more gas discharge lamps (70,72,74,76) comprises an inverter (200), an output circuit (300), and an arc protection circuit (400). Arc protection circuit (400) monitors an electrical signal within the output circuit (300). When an arcing condition occurs at the ballast output connections (302,304,306,308,310), the electrical signal includes a high frequency component having a fundamental frequency that is much greater than the normal operating frequency of the inverter (200). In response to the high frequency component exceeding a predetermined threshold, arc protection circuit (400) disables the inverter (200) for a predetermined shutdown period. Arc protection circuit (400) also provides a restart function for periodically attempting to ignite and operate the lamps.

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: The invention relates to a device for operating a high-pressure discharge lamp, comprising: a switched-mode power supply circuit for supplying power to the high-pressure discharge lamp from a supply voltage, the power supply circuit comprising at least one power switching element, and control means for controlling the at least one power switching element in its switched-on and switched-off states for controlling the power or current supplied to the high-pressure discharge lamp. According to the invention the control means are adapted to control the power consumed by the lamp during its steady phase or the current consumed by the lamp during its run-up phase by controlling the on-time (Ton) of the switched-on state of the at least one power switching element.

Abstract: The present invention discloses a control circuit of power supply with selectable current-limiting modes, wherein the control circuit which maintains the power-output circuit of the power supply within the energy-limiting standard is performed with automatic detection mode. In the present invention, a current-limiting set unit of the control circuit is coupled to the power-output circuit and provides a current-limiting set value according to power-output levels of the power-output circuit and outputs a current-limiting set signal to a current-limiting switch unit. The current-limiting set unit sets up switch junctions on the power-output levels of the power-output circuit, and the current-limiting switch unit receives the current-limiting set signal to determine the state of the switch junctions in order to provide current-limiting detect values of single set or multiple sets of power-output levels for the current-limiting set unit.

Abstract: An incandescent light bulb life extender circuit is designed to attach to the screw base of a conventional light bulb or incorporated in series with the AC powering the bulb. The circuit employs a bidirectional semiconductor switch that reduces the brightness of the bulb marginally while significantly extending the bulb's life. The values of the life extender are selected to operate with standard available light dimmers with no undesirable flicker or compromise of reasonable brightness control. A controller consists of the life extending circuit and a) an appropriate molded insulating housing, b) electrically conductive metallic discs for making electrical contacts to a light bulb base and corresponding socket and c) selected electronic components, connected to said discs, to facilitate the intended electrical performance.

Abstract: A ballast for driving a gas discharge lamp comprising a rectifier stage having an alternating current (AC) input and providing a rectified output voltage, a boost converter stage receiving the rectified output voltage as an input and providing a boosted direct current (DC) output voltage across a DC bus, an inverter output stage for converting the DC bus voltage to a high-frequency AC output voltage to drive the lamp, further comprising a control stage receiving a desired light level signal controlling the desired light level of the lamp and providing an output control signal for turning the boost converter stage on or off in dependency on the desired light level signal. The ballast thereby has reduced power consumption at low light levels for greater energy efficiency.

Abstract: A liquid-activated lighted ice cube includes a battery-powered electrical circuit and LED housed in a hollow body that resembles an ice cube. The circuit includes electrodes exposed to the exterior of the hollow body that, when in contact with water or other liquid beverage, cause the circuit to turn on the LED and illuminate the beverage.

Abstract: Disclosed is a control circuit of an electronic ballast for a fluorescent lamp, wherein the control circuit comprises a protection circuit and an automatic re-lamp circuit. The protection circuit detects an abnormal voltage condition resulted from a defective lamp tube, stops an oscillation circuit of the electronic ballast from generating high voltage output, and thereby protects a worker from an electric shock when the worker attempts to replace the defective lamp tube. The automatic re-lamp circuit turns on a newly installed lamp tube without switching off and on a power supply to the fluorescent lamp first.

Abstract: A low voltage lamp is disclosed and claimed. The low voltage lamp includes a low voltage lamp switch having a first pole permanently connected to a remote source of electric power; a second pole permanently connected to a light; and a movable switch element permanently connected to the first pole and selectively movable into and out of electrical connection with the second pole. In the illustrated embodiment of the invention, the movable switch element includes a flexible cable having a first end connected to the first pole, and an electrically conductive ball mounted to the cable free end. The second pole here comprises a cup adapted to receive and electrically connect to a ball, and the second pole cup is electrically connected to a light.

Abstract: A ballast (10) for powering a gas discharge lamp load (30) comprises an inverter (100), an output circuit (200), and a fault detection circuit (300). During operation, fault detection circuit (300) monitors a first signal and a second signal within output circuit (300) and sets a fault threshold in dependence on the second signal. The second signal is indicative of the type of lamps in the load (30). In response to the first signal exceeding the fault threshold, fault detection circuit (300) issues a shutdown command directing the inverter (100) to cease operation.

Abstract: A rare gas discharge lamp lighting apparatus has a power supply, a transformer, a switching element which is in series connected to the power supply and a primary side of the transformer, a rare gas discharge lamp connected on a secondary side of the transformer, and an input terminal for inputting a lamp lighting signal, a controlling circuit for outputting a controlling signal to the switching circuit by calculating at least one of output voltage, output current and output power, and an operating voltage input terminal to which voltage is impressed to initiate an operation of the controlling circuit based on the lamp lighting signal, wherein a delay element is provided between the input terminal and the operating voltage input terminal.

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: 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 threshold detector for detecting lamp voltage includes an opto-coupler. The opto-coupler includes a radiation-emitting semiconductor element coupled to a source of a sensed voltage and an optically-coupled radiation-receiving semiconductor element with an impedance which varies with received radiation. A switching element coupled to the radiation-receiving semiconductor element produces a first or second signal, depending on the sensed voltage.

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: A discharge lamp unit with noise shields includes a discharge lamp, a discharge lamp control circuit, a filter circuit, the first and the second shield cases, and a power supply. The first shield case shields a discharge lamp control circuit and a filter circuit. The second shield case exclusively shields the filter circuit. Further, a ground wire of the filter circuit and the first shield case are electrically connected. Still further, a ground wire of the control circuit and the second shield case are electrically connected.

Abstract: An integrated fault circuit includes a fault switch interposed between an input power source and an electronic subsystem power bus. A power converter is connected to the electronic subsystem power bus and converts power derived therefrom to at least one voltage output to supply power to an electronic subsystem and at least one fault protection output controlling the fault switch. A fault detection circuit is operatively connected to detect an out of range current on the electronic subsystem power bus and has at least one fault detection output connected to the power converter. When the out of range current is detected on the electronic subsystem bus, the fault detection circuit instructs the power converter, via the at least one fault detection output, to open the fault switch, thereby isolating the input power from the electronic subsystem bus.

Abstract: Circuit arrangement for igniting and operating gas discharge lamps, in particular high-pressure gas discharge lamps. The circuit arrangement comprises four controllable switches (S1, S4) which are interconnected to form a full bridge, in which a gas discharge lamp (EL) is to be arranged in the bridge branch of the full bridge. After the ignition and operation of the gas discharge lamp (EL), a warm-up operation is carried out in which there is a switch-over between the two bridge diagonals (S1, S4; S2, S3) respectively. The gas discharge lamp (EL) is ignited by way of a series resonant circuit (L1, C1) which is coupled to the bridge branch, with two series-connected switches (S1, S2) of the full bridge being permanently open and the other two switches (S3, S4) being switched on and off alternately at a high frequency.

Abstract: An electronic ballast apparatus for powering one or more gas discharge lamps includes an inverter that is controlled by an inverter control circuit. The inverter control circuit adjusts certain ballast operating characteristics in order to operate the lamps under nearly the same operating conditions irrespective of how many lamps are connected to the ballast. The inverter control circuit includes a lamp quantity sensor, a regulator circuit and an end-of-lamp-life sensor. The lamp quantity sensor provides a lamp quantity signal that indicates how many lamps are connected to the ballast. The regulator circuit includes a reference adjustment circuit that receives the lamp quantity signal and provides a scaled reference signal to a reference terminal of an error amplifier. The error amplifier also has a feedback terminal that receives a signal that is proportional to the power delivered by the inverter to the lamps.

Abstract: A discharge-lamp illumination circuit has a DC power supply circuit, a DC-AC conversion circuit, and a control circuit for controlling a voltage from the DC power supply circuit. The DC power supply circuit has a transformer and a first switching element connected in series with a primary coil of the transformer. The activation/deactivation of the first switching element is controlled by the control signal from the control circuit. The transformer is equipped with secondary coils equal in number with the discharge lamps. Each secondary coil is equipped with a second switching element whose activation or deactivation is controlled by a signal from the control circuit. The secondary coils provide different voltages by means of control of the second switching elements.

Abstract: A low-interference lighting system includes a housing, a voltage converter located within the housing, at least one pair of spaced-apart arms serving as electric elongated conductors extending from the housing, and a pair of special contact conductors for an external electrical device to tap into the electric elongated conductors. With respect to each arm, it includes an elongated conductor for carrying electric current and a grounded conducting shield surrounding, but electrically isolated from, the elongated conductor. External electrical devices, such as lamps make electrical contact with the elongated conductor via the contact conductors while insulated from the grounded conducting shield. In one embodiment, the pair of arms are rigid and in another embodiment, they are flexible.

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 current from the isolation circuit exceeds acceptable levels, at which point, the ballast circuit may be shut down, limited or otherwise reducing the possibility of ballast failure. In one form of the invention, a current excursion sensor circuit is coupled between the isolation circuit and the output circuit for sensing when the current from the isolation circuit exceeds a given value. Preferably, the ballast circuit is shut down and maintained inactive until such time as any current excursion has a chance to decay away, ballast components have an opportunity to cool off or otherwise return to normal condition or until such other condition has occurred. Preferably, the ballast is shut down upon a current or voltage excursion of such a magnitude at or before components may overheat or begin to fail.

Abstract: Disclosed is an electric ballast system.

Abstract: A supply circuit used in electronic ballasts for discharge lamps having an inverter for generating a supply voltage at a specified switching frequency for a load circuit comprising at least one lamp and a resonant circuit in series with the electrodes of the lamp. The supply circuit also includes a control circuit connected to the load circuit and the inverter so as to reduce the supply voltage provided to the load circuit in case of defective operation of the lamp. The control circuit includes a band-pass filter centered on the switching frequency of the inverter, a level discriminator, and a logic circuit. The control circuit receives an input signal that is dependent on the voltage at a point of the load circuit, and it is filtered through a band-pass filter. The output signal from the band-pass filter is provided to the level discriminator, which determines whether the lamp being used is defective by the frequency of the voltage and provides a corresponding high or low signal to the logic circuit.

Abstract: A ground fault detection circuit is coupled to an AC circuit and to earth ground for detecting a flow of energy from the AC circuit to earth ground through a path external to the AC circuit. In one embodiment, the ground fault circuit includes a detection circuit coupled to a negative rail of an inverter, which forms part of the AC circuit, and a detection control circuit coupled to the inverter for disabling the AC circuit.

Abstract: A discharge-lamp lighting circuit 1 has a DC-AC converter that incorporates a full bridge circuit consisting of a plurality of pairs of switching devices. The discharge-lamp lighting circuit incorporates an anomaly detector for detecting an anomalous state of the lighting circuit, and a current detector for detecting whether or not an electric current flows in the full bridge circuit in a state where the operation of the lighting circuit is stopped owing to detection of an anomalous state of the lighting circuit by the anomaly detector. The discharge-lamp lighting circuit also includes a device-stage determining unit structured such that when a current has been detected by the current detector, a pair of switching devices, of the switching devices connecting the full bridge circuit and disposed in the higher stage, are switched on. Another pair of the switching devices, disposed in the lower stage are switched off.

Abstract: An electronic ballast includes a zener diode in series with the bulk capacitor of the ballast to provide a charging voltage for a small capacitor that powers a power factor correction circuit within the ballast. A SCR in parallel with the zener diode shuts off the zener diode after the power factor correction circuit begins operation.

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

Abstract: A compact, rugged, long-lasting, battery-powered light fixture suitable for use as an emergency signal, marker, or flashlight has a lighting element made from a phosphorous-based luminescent film section curled into an arcuate shape and packaged within a transparent tubular enclosure. The AC power supply and batteries are held in the center of the enclosure inside the lighting element.

Abstract: An electronic ballast lighting power control device including: a power switch controlled to provide a lighting power dim control signal to order the ballast providing an interrupted electric wave power output to the lighting fixture, and at least one electronic ballast respectively connected to the power switch and simultaneously controlled by the lighting power control signal of the power switch to provide an interrupted electric wave power output from the ballast to the lighting fixture, each of the at least one electronic ballast consisting of a filter, a rectifier, a power factor controller, a logic controller, an oscillator, and a protection circuit.

Abstract: A lighting circuit for a discharge lamp is designed in such a way that a detection time for the flicker state of a discharge lamp is not affected by the light-OFF time at the time the discharge lamp flickers without causing a significant increase in cost.