Abstract: A light control installed in a ceiling fan and lamp assembly and adapted to control the light intensity of lamp means of the ceiling fan and lamp assembly, the light control having an overload/short circuit protection circuit formed of an amplifier and a comparator and adapted to automatically cut off power supply from the ceiling fan and lamp assembly upon an overload or short-circuit.

Abstract: A safety switch for a lamp is disclosed. The safety switch comprises a pair of electrodes having cylindrical shapes. Each electrode comprises an internal face with a conical cavity therein. The electrodes are arranged so that they are adjacently mounted with an aperture formed between the two conical cavities. In addition, there is a metal ball placed within the conical cavity. The metal ball forms a connection or disconnection of the electrodes. In one embodiment of the invention, the electrodes are horizontally mounted, and when the lamp is displaced from an upright position, the ball rests along the aperture formed between the two electrodes, thereby providing a connection of the electrodes and power and luminescence to the lamp. When the lamp is displaced from the upright position, the ball moves away from the aperture, thereby disconnecting the electrodes and power and luminescence to the lamp.

Abstract: An electronic ballast for a low-pressure discharge lamp (LA) contains an inverter that is fed with direct voltage (UBUS) and the output of which is connected to a load circuit containing terminal contacts for the lamp (LA), a heating transformer that has a primary winding (Tp), which is connected to the output of the inverter, and a respective secondary winding (Ts1, Ts2), which is located in a heating circuit with a coil (W1, W2), for heating each of the two electrodes of the lamp (LA), and a series circuit arrangement that is connected in parallel with the load circuit and which contains the primary winding (Tp) of the heating transformer and an electronic switch arrangement (S3, S4). For the purpose of identifying the type of lamp and the state of the lamp, the currents in one of the two heating circuits and in the primary winding (Tp) of the heating transformer are measured and evaluated.

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: The invention relates to a circuit arrangement for operating at least one discharge lamp (LP) on a half-bridge inverter (Q1, Q2), having at least one coupling capacitor (C3) and having a switch-off device (T1, A) which permanently switches off the half-bridge inverter (Q1, Q2) when the lamp (LP) refuses to start. According to the invention, the circuit arrangement has first and second devices (V1, V2) for monitoring the voltage drop across the at least one coupling capacitor (C3) and for activating the switch-off device (T1, A) as a function of the voltage drop detected across the at least one coupling capacitor (C3). If the voltage across the coupling capacitor (C3) deviates substantially from its normal value, for example owing to the occurrence or the rectifying effect at the end of the service life of the discharge lamp (LP), the half-bridge inverter (Q1, Q2) is shut down by the switch-off device (T1, A).

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 fault protection circuit for fluorescent lamp ballasts cuts off ballast power to the lamp in response to fast rise-time changes but not slower changes in either current output or voltage output of the ballast. The fault protection circuit is compatible with different ballast circuit topologies and features a floating reference level which renders the circuit insensitive to the lamp load wattage, making the circuit particularly useful in so-called universal ballasts.

Abstract: A lamp with a temperature-controlled automatically protecting circuit which includes a temperature induction circuit and a sampling circuit with its input end to connect with an output end of the temperature induction circuit, wherein the temperature control automatically protecting circuit further includes: a comparing circuit which has an input end to connect with an output end of the sampling circuit and when a positive voltage drop across the sampling resistance of the sampling circuit is lower than a reference voltage, the comparing circuit will have a high electrical level output; a trigger circuit which has an input end to connect with an output end of the comparing circuit and a thyristor which can be triggered by the high electrical level output of the comparing circuit to have the trigger circuit in the on state; and a maintaining circuit which has a capacitance in parallel with the thyristor in the trigger circuit and which, after being in series with a resistance, have a low electric level output

Abstract: A lamp incorporating one or more safety features for reducing the risk of fire or heat damage associated with improper operation of the lamp. One safety feature can be an automatic safety switch for terminating power to the lamp when the lamp is not in a proper operational orientation. The switch is mounted on the underside of the base of the lamp and only provides electricity to the lamp when the weight of the lamp rests properly on its base. A thermal switch which reduces or eliminates power to the lamp when the lamp is operating above a predetermined temperature can be provided, alone or in combination with a light level senor to adjust lamp power in response to room lighting conditions.

Abstract: A protection circuit protects from overheating a switching transistor that delivers current from a power source to a daytime running light on a vehicle. The protection circuit of the present invention open-circuits the switching transistor from the power source when the temperature at the switching transistor is sensed to be above a predetermined temperature. In this manner, excessive current is prevented from flowing through the switching transistor. In contrast, prior art protection circuits control only the gate of a MOSFET or base of a BJT switching transistor. In that case, if damage to the transistor results in an effective resistance, constant flow of current through such an effective resistance results in excessive overheating or even a fire. The protection circuit of the present invention open-circuits the conductive path from the power source through the effective resistance such that current does not flow through the effective resistance.

Abstract: A series resonant ballast safety control circuit for controlling the operation of a ballast when a lamp is removed from a lamp fixture. The safety control circuit senses a diode clamp current and activates a transistor to ground one of the terminals of a dimming control circuit. The dimming control circuit reduces the duty cycle of one of the inverter transistors to decrease the available output voltage and reduce the through-lamp leakage current to safe levels. Once the lamp is replaced in the lamp fixture, the safety control circuit no longer controls the dimming control circuit and the ballast returns to normal operation. In another embodiment, the safety control circuit is used with a boost power factor correction circuit in a non-dimming ballast system to reduce the current provided to the lamp load.

Abstract: In an externally controlled electronic ballast, a driving circuit which requires a dedicated supply voltage is provided for the purpose of driving an inventor half bridge. The driving circuit is constructed such that the inventor half bridge blocks when the supply voltage V.sub.cc falls below a threshold value UVLO. Via a self-holding controllable electronic switch and a Z diode DZ2, a voltage monitoring circuit draws the supply voltage V.sub.cc below the threshold value UVLO when an excessively high lamp voltage is detected. The ballast is thereby inactive. A current sensing path which leads via at least one filament of the low-pressure gas discharge lamp serves to detect a change of lamp. The current sensing path controls a further electronic switch, which is likewise connected to the supply voltage V.sub.cc of the driving circuit and can, when it conducts, draw said voltage further to frame than the first switch.

Abstract: An electrical power system to provide a selected voltage to a load such as a fluorescent lighting system is characterized by a winding 3 having a positive end connected to a positive rail and is tapped at a predetermined position for supplying an output terminal with a selected voltage. A first relay contact can electrically connect a neutral end of the winding to a neutral rail to provide one selected voltage or a second relay contact can electrically short-circuit a predetermined number of turns of the winding in response to a request for a second selected voltage. When a fault condition is monitored, a third relay contact can electrically short-circuit the neutral end of the winding to the predetermined position to put the system into a failsafe condition which prevents turns of the winding being open circuit.

Abstract: A luminaire diagnostic system including a lamp and a photocontroller for automatically turning the lamp on during periods of darkness and off during periods of daylight wherein the photocontroller includes detector circuitry for detecting the load drawn by the lamp, a microprocessor, responsive to detected load and programmed to predict a condition of the lamp such as a cycling event and/or lamp out condition based on the load drawn by the lamp, and an indicator such as a visual alarm for indicating the occurrence of the condition detected and/or a transmitter for transmitting the detected condition to a remote location. Also, upon cycle detection, the lamp may be turned off to prevent damage to fixture components.

Abstract: The present invention relates to a device for starting and supplying a fluorescent tube, including a resonant system connected to the tube and to a rectified supply circuit with a switch in series. A first detector controls the switch to turn off when the current provided by the supply exceeds a determined threshold; and a second detector controls the switch to turn on for each transition through zero of the voltage on a node of the resonant system and for each transition through a minimum of this voltage.

Abstract: A lighting dimmer for controlling the current through a lighting load includes circuitry for applying a predetermined dimming level control signal to a control circuit in response to the absence of a dimming level control signal and the cycling OFF and ON of a circuit breaker. The dimmer further includes voltage compensation circuitry for maintaining a constant lighting load current notwithstanding short-lived changes in nominal line voltage.

Abstract: An annulus fluorescent lamp comprises two annulus fluorescent tubes formed into shapes having different diameters and disposed substantially concentrically in substantially the same plane. Each of the annulus fluorescent tubes has a first end with an electrode seal portion and a second end without electrodes. The second ends of the annulus fluorescent tubes are communicated with each other via a bridge portion so that a single discharge path is formed inside the plurality of annulus fluorescent tubes. The annulus fluorescent lamp also comprises a mouthpiece covering the first and second ends of the annulus fluorescent tubes, and a thermal fuse disposed in the mouthpiece and close to the electrode seal portion of the annulus fluorescent tubes. The thermal fuse is connected electrically between one of outer lead wires of the electrodes and one of lead terminals fixed to the mouthpiece.

Abstract: Abnormal states in a high-voltage cable connected to a backlight of a liquid crystal display are detected. This invention includes: a secondary winding of a transformer; a discharge tube connected to the secondary winding of the transformer; means connected to the discharge tube for detecting a tube current; means connected to the secondary winding of the transformer for detecting a transformer current; and abnormal-state detection means for comparing a value of the tube current detected by the tube current detection means with a value of the transformer current detected by the transformer current detection means and interrupting a power supply if a difference greater than a predetermined value is detected. Thus, a case of lighting delayed due to the darkness effect can also be dealt with.

Abstract: A circuit is proposed for the AC voltage operation of a discharge lamp by ans of a coupling capacitor (C3) with a safety disconnection device, connected in series with the lamp for DC current separation, which is characterized by the fact that the safety disconnection device responds to a DC voltage (UC3) at coupling capacitor (C3) by means of a DC current component flowing through the lamp.

Abstract: A circuit for protecting electrically operated lighting elements used for illumination or signaling has at least one PTC resistor connected serially upstream of the lighting element. In another embodiment, the circuit has a self-regulating current supply connected serially upstream of the lighting element. In yet another embodiment, the circuit has a down convertor connected serially upstream of the lighting element.

Abstract: A light module for use with a light source mounted to footwear, includes a battery power supply; a cantilevered coil spring which forms a switch connected between the power supply and the light source and having open and closed states such that the light source emits light at a first illumination intensity when the switch is in the closed state; and a fading control circuit connected to the power supply, the light source and the switch for controlling the supply of power to the light source when the switch changes from the closed to the open state such that the illumination intensity of light from the light source decreases over time to produce a fading effect for a first predetermined period of time, regardless of whether the switch changes back from the open state to the closed state during the first predetermined period of time.

Abstract: A lamp ballast circuit drives at least one gas discharge illumination device and includes first and second MOS-gated power semiconductor devices connected in a half-bridge configuration and coupled across a d-c supply with a common terminal located at the node between the devices for supplying an output signal to the illumination device. A self-oscillating driver circuit includes respective outputs for driving the power semiconductor devices and has at least one operating voltage supply terminal. When the illumination device fails or is removed, a protection circuit, electrically coupled to the illumination device, removes the operating voltage supplied to the supply terminal. The protection circuit includes a transformer/inductor coupled to the illumination device or a switch that is responsive to the voltage across the illumination device. Additionally, a soft-starting circuit can be provided for gradually increasing the voltage across the illumination device prior to igniting the illumination device.

Abstract: A lighting circuit for a discharge lamp includes lighting control circuit for controlling the lighting of a discharge lamp, ignition means for supplying a trigger pulse to the discharge lamp and a socket. Power is supplied to the discharge lamp via terminals of the socket and terminals of a connector section of the discharge lamp. The socket and the connector section are respectively provided with connection terminals which are to be connected together while the discharge lamp is connected to the connecting member. When those connection terminals are not connected together, the supply of power and the supply of the trigger pulse to the discharge lamp are inhibited. This prevents problems (damaging insulation, an electric shock and the like) from arising when the lighting circuit is activated while the discharge lamp is not connected to the lighting circuit.

Abstract: A ballast system for at least one dimmable fluorescent lamp includes a resonant switching inverter and a controller which controls the inverter to operate above resonance during starting and normal running operation. After a start delay timer allows time for the lamp filaments to heat up, the controller provides control signals to a gate driver to drive the switching devices of the switching inverter initially at a relatively high frequency and then reduces the frequency until a sufficiently high voltage is reached to start the lamp. Once the lamp is started, the inverter is operated in its normal feedback mode. The ballast system further includes an overvoltage shutdown mechanism. During lamp starting, if either the output of the start delay timer is high or the output voltage is greater than a first overvoltage shutdown threshold, then an overvoltage shutdown timer is activated to shut down operation of the inverter for a predetermined overvoltage shutdown period.

Abstract: Footwear includes a heel; an upper; a light source mounted to at least one of the heel and upper; and a light module positioned within the heel, the light module including a power supply for supplying power; a capacitor for storing power from the power supply and for discharging the stored power, the capacitor being connected with the light source to activate the light source; a switch for alternately opening and closing a connection between the power supply and the capacitor upon movement of the footwear, such that when the switch closes the connection, the capacitor charges to a full capacity thereof as determined by the power supply, and the light source is activated to emit light at a first intensity in accordance with the full capacity of the charge on the capacitor, and when the switch opens the connection, the capacitor discharges from the full capacity thereof, and the light source is activated to emit light at an intensity less than the first intensity and which decreases over time, in accordance wit

Abstract: A circuit arrangement for operating a discharge lamp (LA), provided with input terminals (K1, K2) for connection to a supply voltage source. A rectifier (D1-D4) is coupled to the input terminals for rectifying a supply voltage delivered by the supply voltage source. A capacitor (C2) is coupled to the rectifier and a DC-AC converter (III) is coupled to the capacitor and is provided with terminals for accommodating a discharge lamp. The circuit arrangement is also provided with a circuit I (R1-R6. T1, T2, C1, V, VI, VII) for detecting periodic current pulses having an amplitude greater than a given value W1 and with a circuit II (IIa, S1) coupled to the circuit I for changing the operational state of the circuit arrangement. As a result, damage to the circuit arrangement is prevented when the circuit arrangement is used in combination with a dimmer unsuitable for the circuit arrangement.

Abstract: An anti-burn device which can prevent a floor lamp from burning material covering thereon is disclosed. The anti-burn device includes a photoresistor and a detecting control circuit. The photoresistor has a photo-sensitive surface receiving light reflected back to the floor lamp. When the photoresistor receives the reflected light, the detecting control circuit will cut off the power supply to the halogen bulb. Therefore, burning of the material draped on or against the floor lamp can be avoided.

Abstract: A halogen torchiere lamp comprises a grid-like guard arranged across the lampshade opening for preventing flammable material from making contact with the hot glass shield of the bulb or the bulb itself. A temperature sensor is installed within the lampshade near the bulb to sense the rise in ambient temperature within the lampshade should its opening be covered by any material. The sensor comprises a thermostat that de-energizes the bulb when the sensed ambient temperature reaches a predetermined value. The sensor may also comprise a thermistor that operates the dimmer switch of the lamp to dim the bulb when the sensed ambient temperature reaches a predetermined value. The sensor may further comprise a photocell-powered thermistor that varies the bias of a transistor, which in turn causes the bulb to dim, thereby lowering the ambient temperature within the lampshade.

Abstract: A single, integrated circuit combining both a restrike ignitor and a digital timer cutout which generates high voltage pulses for starting and restarting high intensity discharge lamps, including high pressure sodium lamps, without generating an excessive amount of heat.

Abstract: The invention relates to a circuit arrangement for operating electric lam and an operating method for electric lamps. The circuit arrangement has an inverter ((Q1, Q2) with a switch-off device which switches off the inverter (Q1, Q2) in the case of an anomalous operating state. The switch-off device has a field-effect transistor (T1, T1') whose drain-source junction is arranged in the control circuit of an inverter switching transistor (Q2) and switches the control circuit of the inverter transistor (Q2) between a state which is of low resistance in normal operation and a state which is of high resistance in anomalous operation. After the occurrence of an anomalous operating state, it is advantageous to switch off synchronously with the blocking phase of the inverter transistor (Q2) in whose control circuit the field-effect transistor (T1, T1') is arranged.

Abstract: A ballast includes safety circuitry which senses lamp status through various phases of ballast operation. According to one feature, the ballast is prevented from supplying an output voltage upon initial energization of the ballast when a lamp is not present at the output terminals. The presence of a filament is sensed via a DC path extending through the filament heater windings of an output transformer. When the DC path is not complete, a control input, for example the power supply input of the ballast controller, is not provided with a voltage to start ballast operation. The DC path is also used to restart the ballast if a defective lamp is replaced with a good one. Over-voltage and capacitive mode detection is also disclosed to shut down ballast output upon lamp failure/removal.

Abstract: A switch for use in an AC circuit wired in a three-way switch mode for supplying power to a load, has a first terminal for connection to an external line, second and third terminals for connection respectively to corresponding terminals of a second like switch, and a switch contact for selectively connecting the first terminal to either one of the second and third terminals. A transformer has its primary winding connected between the first terminal and the external line, and its secondary winding deriving an output voltage therefrom. The output voltage is rectified and supplied to a light-emitting diode. The ratio of turns of the windings of the transformer is such that the rectified voltage energizes the light-emitting diode when power is supplied to the load over its normal operating range. The light-emitting diode will thus provide an indication of when power is supplied to the load.

Abstract: The present invention discloses a control module that provides improved control over the ignition of a fluorescent lamp. In one aspect, the control module determines whether the lamp is lit and, when the lamp is not lit, determines whether the power supply line voltage is insufficient to sustain the lamp in a lit state after ignition. When the power supply line voltage is determined to be insufficient, the control module waits until the power supply line voltage rises to a sufficient level before igniting the lamp.

Abstract: In accordance with the present invention, a hybrid sequence start circuit is provided for operating a plurality of instant start lamps. The circuit utilizes two coils, a primary and a secondary, and an electronic switch to start a plurality of series-connected, instant start lamps in sequence. When the circuit is energized, the electronic switch causes open circuit voltage to be applied to a first lamp by placing a low impedance across the other lamps, causing the first lamp to strike. The first lamp then conducts current, causing a starting capacitor in parallel with a second lamp to be charged, eventually, causing the second lamp to strike. The current through the second lamp shunts current away from the switch, and when this current drops below a predefined threshold level, the switch opens, effectively removing both the low impedance and the starting capacitor from the circuit.

Abstract: The method operates at least one fluorescent lamp (FL) using an electronic ballast. The ballast has a rectifier bridge (GL) which has AC mains voltage (L, N) across it, a connected step-up converter (L1, D1, V1), a half-bridge circuit (V2, V3) as well as a control loop (IC) for continuously monitoring the lamp current by means of a controlled drive circuit (CCO, SEL, HSD, LSD) of the power transistors (V2, V3), which drive circuit keeps the lamp current constant during normal operation. A timer (PST, IT, CT), which is started in a defined manner each time the lamp is started or a disturbance is detected, generates as superordinate control a time base for a monitoring circuit (MON). The monitoring circuit evaluates the instantaneous lamp current using predetermined reference levels (Mp, Mi and Mo) which vary in individual time segments (.DELTA.pt, .DELTA.it, .DELTA.st, .DELTA.

Abstract: The invention relates to a measuring circuit for detecting the amount of deposited electrode material on the wall of a lamp vessel of a discharge lamp by measuring the power of infrared radiation within a specific wavelength range, comprising a detector for generating an electrical signal constituting a measure for the power of the infrared light in said specific wave length range. According to the invention the measuring is done in a time lapse starting after a predetermined time interval following the extinguishing of the discharge lamp. An increased accuracy of the measurement is thereby realized.

Abstract: A ballast includes safety circuitry which senses lamp status through various phases of ballast operation. According to one feature, the ballast is prevented from supplying an output voltage upon initial energization of the ballast when a lamp is not present at the output terminals. The presence of a filament is sensed via a DC path extending through the filament heater windings of an output transformer. When the DC path is not complete, a control input, for example the power supply input of the ballast controller, is not provided with a voltage to start ballast operation. The DC path is also used to restart the ballast if a defective lamp is replaced with a good one. Over-voltage and capacitive mode detection is also disclosed to shut down ballast output upon lamp failure/removal.

Abstract: A high reliability portable incandescent illumination system for use in applications which require a reliable, high output light source such as heliport markers, runway lights, warning lights, road hazard and obstruction lights. The required elements of the invention are a battery to provide an energy source, a DC/DC converter to step up the battery voltage to a level required to drive a high output light source. The DC/DC converter is driven by a controller which generates a pulse stream to the DC/DC converter based upon inputs from a soft start circuit, a filament temperature sensor, an optical spectrum sensor, a power sensor and a filament break sensor. The optical spectrum sensor is coupled to the light source by a fiber optical element. An improvement in results in the performance of portable beacons by using high voltage lamps with low voltage batteries via voltage step-up electronics.

Abstract: In an electronic flash apparatus having a flash tube (2) which is disposed inside a reflector (3), having a storage capacitor (5) which can be discharged via the flash tube having a d.c. voltage converter (7) which is fed by a d.c. voltage source, preferably a battery (6), and by means of which the storage capacitor (5) can be recharged to its operating voltage following each discharge, and having a control circuit (8) which switches the d.c. voltage converter (7) on or off as a function of the voltage at the storage capacitor (5), overheating of the reflector (3) and/or its front elements (4) is prevented by a protective circuit (12) which influences the flash light emission in such a way that the temperature of the reflector (3) and/or its front elements (4) does not exceed a predetermined maximum value.

Abstract: A lighting circuit converts the output voltage of a DC booster circuit to an AC voltage which is in turn supplied to a discharge lamp connected between AC output terminals. The lighting circuit comprises a short-circuit detector for detecting a change of a DC voltage from the DC booster circuit to a square-wave voltage when short-circuiting between one of the AC output terminals and ground occurs, and sends a detection signal via a hold circuit to a power cutoff relay circuit. As a result, a relay contact in the power cutoff relay circuit is opened to inhibit the operation of the lighting circuit.

Abstract: An arc detection and cut-out circuit is connected to an electronic ballast to detect when arcing occurs and to disable the ballast when arcing occurs. The arc detection and cut-out circuit is comprised of a current detector and a shunt circuit. The current detector detects the current in the electronic ballast to determine if arcing has occurred. If detected, the current detector causes a shunt circuit to shunt the power inverter of the ballast shutting it down. The arc detection and cut-out circuit prevents the power inverter from starting up until the power to the ballast is cycled off and back on.

Abstract: An automotive ignition system lockup protection circuit utilizes a capacitor charging/discharging circuit to generate a periodic clock signal. A counter circuit activates an ignition coil deenergizing signal after a predetermined number of clock signal. The capacitor charges and discharges within a voltage reference window defined as the difference between a first reference voltage and a second larger reference voltage, wherein the first reference voltage is functionally related to a variable battery voltage and the second reference voltage is fixed and independent of battery voltage. The frequency of the periodic clock signal is modulated in accordance with the voltage reference window to thereby vary the lockup time in accordance with battery voltage. The capacitor charging and discharging current is adjustable to compensate for variations in the capacitor value and the entire circuit operates consistently over a temperature range typically required in an automotive application.

Abstract: A ballast includes an inverter for providing an AC voltage to a discharge lamp. As the lamp approaches end-of-life, a DC voltage component develops across the lamp. The ballast includes circuitry for monitoring the condition of each of the cathodes by measuring this DC voltage component. After a predetermined increase in this DC voltage component, the inverter is disabled in order to prevent excessive heating of the cathodes. The inverter is also disabled as a result of a resonant or near resonant mode condition of a tank circuit caused by an open circuit condition or a leaking lamp.

Abstract: A lighting unit including an illumination element, and an electric circuit comprising electric power supply leads, coupled with the illumination element and operable to deliver electric power to the illumination element for actuation thereof, having an electric fuse integrally coupled to at least one of the leads to provide electrical isolation of the lighting unit in the event of an electrical short therein. The invention has particular utility in application to electroluminescent lamp units, of a type which is usefully employed in assembly of multi-unit electroluminescent lamp arrays. When provided in a parallel circuit arrangement comprising a multiplicity of individually fused lamps on a common power feed, the failure of any one lamp will not cause any other lamp to cease operation.

Abstract: The first purpose of the invention is to provide cordless light irradiation in which a stable amount of light is emitted when irradiating, and moreover, the device can be made compact. The second purpose is to offer a cordless light irradiation device that can control the battery temperature during use to a lower temperature than in the past.Halogen lamp 1 equipped with a reflective mirror and batteries 4 are housed in handpiece 2. The device is equipped with battery case 3 that is provided with ventilation holes 5, cooling fan 6 and optical filter 7, and lamp guide 8 is provided on the terminal of handpiece 2.

Abstract: An electroluminescent lamp includes at least one bus bar attached to an electrode of the lamp. The bus bar has a gap and a conductive trace bridges the gap. The trace is preferably an isolated segment of the front electrode of the lamp and is made when the front electrode is patterned. The bus bar includes at least one pair of holes extending through the bus bar. The holes each have a diameter less than the width of the bus bar and are spaced along the length of the bus bar. The segment of the bus bar between the holes can be curved to define a path through the holes adjacent the bus bar. A conductive pin through the holes makes electrical contact with the bus bar and is held in place by the holes and the curved segment. The bus bar is an integral connector and the conductive trace is an integral fuse.

Abstract: A low voltage lighting fixture connected to an isolation step-down transformer is protected from limited or maximum short circuit conditions by monitoring the secondary current of the step-down transformer until a fault is detected, whereupon the protection circuitry deenergizes the primary of the transformer by opening a relay. The protection circuitry is completely isolated such that a breakdown in voltage from the primary to secondary of the stepdown transformer, which would place 120 volts on the secondary side, cannot occur. Additionally, while monitoring the high current-low voltage secondary of the transformer, the relay is placed in the primary circuitry which is at line voltage, but at a much lower current rating. The relay is a normally open device which closes when either of a pair of redundant optoisolators conduct current.

Abstract: Disclosed is a lighting circuit for a vehicular discharge lamp, which can accurately and promptly detect an abnormal status to thereby improve the reliability and safety usage. When a lighting switch in the lighting circuit is set on, a batter/voltage is boosted by a DC booster circuit and then converted into an AC voltage by a DC/AC converter before being supplied to a metal halide lamp. When power supply continues with the lamp in an open-circuit state or a short-circuited state, a fire may be set or an electric-shock originated accident may occur. An abnormality detector for detecting an abnormal status is provided to cope with such a problem. The abnormality detector detects the output voltage of the DC/AC converter, very close to the lamp voltage, determines that the lamp in the open-circuit state when the detected level is equal to or above a predetermined value and determines that the lamp in the short-circuited state when the detected level is equal to or below a predetermined value.

Abstract: A monitoring apparatus is included in each street light of a plurality of street lights. Each monitoring apparatus monitors the operation of the associated street lamp and stores data representing the operation thereof. Data is sent from each monitoring apparatus to a monitoring station, via the power supply cables connected to the street lamps, under control of the monitoring station. The monitoring station stores the data until it is requested to transfer the data to an interrogating station. The data is then analysed to identify faulty street lights.

Abstract: The present invention is directed to an electronic ballast device for the control of gas discharge lamps. The device is comprised of a housing unit with electronic circuitry and related components. The device accepts a.c. power and rectifies it into various low d.c. voltages to power the electronic circuitry, and to one or more high d.c. voltages to supply power for the lamps. Both the low d.c. voltages and the high d.c. voltages can be supplied directly, eliminating the need to rectify a.c. power. The device switches a d.c. voltage such that a high frequency signal is generated. Because of the choice of output transformers matched to the high frequency (about 38 kHz) and the ability to change frequency slightly to achieve proper current, the device can accept various lamp sizes without modification. The ballast can also dim the lamps by increasing the frequency. The device can be remotely controlled.