Abstract: A projector includes a projection lens, an optical engine, and a light device. The light device has a lighting axis and includes a movable frame, two light sources fixedly disposed on the movable frame, and a driving part kinematically connected with the movable frame. The driving part is disposed in front of the two light sources. The driving part moves the movable frame such that the two light sources moves simultaneously so as to selectively make one of the two light sources emit light along the lighting axis, which avoids single light source operating for long time. The optical engine is disposed close to the light device and has a light entrance axis. The light entrance axis coincides with the lighting axis. The optical engine includes a digital micromirror device that modulates light from the light device to be projected out the projector through the projection lens.

Abstract: An illumination system and methods for controlling the illumination system are provided. In one embodiment, the method includes providing a plurality of illumination sources, monitoring optical output power of the plurality of illumination sources over a period of time, and controlling the plurality of illumination sources to maintain a predetermined level of optical output power. The method further includes compensating for degradations of one or more of the plurality of illumination sources to maintain the predetermined level of optical output power, predicting a lifetime of the illumination system based on the parameters of the plurality of illumination sources, and performing periodic maintenance of the plurality of illumination sources according to a quality control schedule.

Abstract: A controller for a light fixture includes: a current-sampling circuit adapted to be connected electrically to the light fixture, and operable to generate a voltage signal corresponding to a current flowing through a light source of the light fixture; a voltage-processing circuit operable to perform at least one of voltage-amplification and voltage-rectification processes upon the voltage signal so as to generate a recognition signal; a signal-recognition unit configured to generate a control signal according to the recognition signal; a driver unit operable to generate a driver signal corresponding to the control signal; and a driving component adapted to be connected electrically to the light fixture, and driven by the driver signal for controlling operation of the light source of the light fixture.

Abstract: A light-emitting diode illumination circuit includes light-emitting diodes connected in series and compensating elements connected in parallel with the light-emitting diodes. Each of the compensating elements includes positive and negative terminals and at least one conductor having a predetermined melting point. The conductor melts in the event of open-circuit failure so that the terminals are connected.

Abstract: This invention is for an improved high intensity discharge lighting fixture. The lighting fixture includes a ballast which is adapted to be connected to a source of electric power. A first high intensity discharge socket is electrically connected to the ballast. A second high intensity discharge socket is electrically connected in parallel to the first high intensity socket and the second high intensity discharge socket is connected to the ballast in parallel with the first high intensity discharge socket.

Abstract: A detecting device can centrally monitor and detect a lamp failure of one or more lamps connected in series such as guide lamps in the runway of an airfield. A core (12) is disposed on a power line (P.sub.1) of each lamp (L.sub.1 -L.sub.n). The power line (P.sub.1) is wound on the core (12) as a first winding (N.sub.1). A second winding (N.sub.2) for extracting the power of the power line (P.sub.1) is wound on the core (12). An oscillator (13) is provided which uses the output voltage of the second winding (N.sub.2) as the power supply to generate a frequency corresponding to each lamp (L.sub.1 -L.sub.n). The output signal from this oscillator (13) is fed back to the power line (P.sub.1) through a third winding (N.sub.3). Accordingly, a signal consisting of a frequency which represents each lamp flows through the lamp circuit and any failed lamp or lamps can be detected by checking this feedback signal.

Abstract: A two-filament incandescent lamp and operating circuit well suited to lighting applications requiring high service reliability. In the lamp, the rated operating voltage of the second filament is greater than that of the first filament. In the operating circuit, there is an inductive reactance in series with the lamp and, in one aspect of the invention, an electrical connection across the lamp terminals for measuring the operating voltage of the lamp. After the power and rated wattage of both lamp filaments have been selected, matched values of inductive reactance and open circuit voltage of the operating circuit can be uniquely determined such that the following advantages are obtained. When the first lamp filament fails, the second filament comes into full brilliance. In a preferred embodiment of the invention, there will be no significant change in the luminous output of the lamp before and after failure of the first filament.

Abstract: The invention consists of an electrical circuit for a vehicle headlight system whereby the conventional parallel circuit connection of headlights is automatically converted into a series circuit connection under conditions appropriate for daytime running lights, whereby the light output of the headlights is reduced as compared to that in conventional headlight circuit mode, and a method for interconnecting such circuit with conventional headlight systems.

Abstract: An AC polarity-reversing bridge ballast for an arc discharge lamp using an incandescent filament for resistive ballasting and standby illumination powers the filament during hot restart without modifying the low duty cycle operation of the starting oscillator and without introducing additional power switches. The switching elements of the polarity-reversing bridge serve the dual functions of reversing the polarity of the voltage supplied to the arc lamp during normal running conditions and energizing the filament during a restart condition.

Abstract: A lamp and lamp circuit apparatus are provided in which the lamp has a plurality of filaments operable one filament at a time and driven by a plurality of filament drivers. A filament failure detector circuit is operatively connected to one or more filament drivers for detecting the failure of the filament being driven. A circuit actuates a second filament in the multiple filament bulb when the filament failure detector detects failure of one filament, so that a lantern, and especially flashing lanterns, can have an extended lamp life.

Abstract: An alternating current lampchanger control circuit for driving a rotatable turret having a plurality of lamps, such as used in a navigational light. An input receives pulsed alternating current signals and is connected to a power circuit including fixed contacts for supplying the pulsed signals to one of the lamps in the turret. A lampout sensing circuit includes a transformer which has a primary in the lamp power circuit and has a rectifier connected to the transformer secondary. Switching means are connected to the rectifier and are actuated to an on position by a lamp failure. An alternating current turret motor is connected to the input or to a continuous source of alternating electrical current through the switching means for rotating the turret upon a lamp failure. The switching means may include a first triac controlling a second triac connected to the motor. Third switching means are included in a feedback loop to provide an alternating current drive for the motor in a continuous mode.

Abstract: A marker or clearance light for semi trailers and the like which increases the life by a factor of from 3 to 10.

Abstract: A position sensor for a rotatable lamp changer turret having a plurality of lamps which are rotated in sequence to an operating position as the lamps burn out. A circular cam is positioned on the turret that includes a first position indicating portion for each of the lamps for indicating when each of the lamps is in the operating position. The cam includes a second position indicating portion for indicating that all of the lamps have been rotated past the operating position. The second position indicating means is located for stopping the turret in a position with all the lamps out of the operating position for providing a visual alarm indication. A cam follower engages the cam and in turn actuates electrical switch means for controlling rotation of the turret. A third cam portion is positioned between each of the first cam portions for actuating the cam follower and the switch means for maintaining turret rotation until the first cam portions are engaged by the cam follower.

Abstract: A photocell illuminated by the projection lamp of a slide projector controls a spring-biased longitudinally movable lamp exchange carrier. Lamp failure causes a change of state in the photocell that electronically releases an electromagnetic lock and allows the spring-tensioned lamp carrier to change positions. The last spare lamp is screened from the photocell, causing the electronic circuit to energize a fluorescent diode to indicate that the last spare lamp is being used.

Abstract: A marker or clearance light for semi trailers and the like which increases the life by a factor of from 3 to 10.

Abstract: A lamp out detection circuit is provided for a buoy lamp changer. The circuit includes an modified Hartley transistor oscillator which is tuned to operate at a preselected frequency. A typical lamp flasher applies power to the lamp and the lamp out circuit, simultaneously. If a normal lamp is in operation, a current pulse is inductively coupled to the oscillator in a manner suppressing sustained oscillation. Should the filament of an incircuit lamp fail or become electrically non conductive, the lack of inductive coupling to the oscillator would permit sustained oscillation which results in generation of a pulse signal. Time delay means are provided to ensure that the pulse signal is not intermittent. Further indexing through a time delay is provided to permit the lamp changer to rotate a new lamp into an operating position before further monitoring of faults occurs. Means are provided to prevent rotation of the turret after the last lamp has failed.

Abstract: The invention consists of an electrical circuit for a vehicle headlight system whereby the conventional parallel circuit connection of headlights is automatically converted into a series circuit connection under conditions appropriate for daytime running lights, whereby the light output of the headlights is reduced as compared to that in conventional headlight circuit mode, and a method for interconnecting such circuit with conventional headlight systems.