Abstract: An exit sign includes a main body, a front panel and at least one light source. The main body includes a rear portion, a peripheral side portion and an opening. The peripheral side portion has a first translucent area which is U-shaped. The front panel is received in the opening and includes a symbol indicating a location of a building exit, with the symbol establishing a second translucent area. The at least one light source emits light through the first and second translucent areas, with the first translucent area providing lighting directly in front of the exit sign, directly below the exit sign and directly on either side of the exit sign. The exit sign is particularly configured to be mounted low on a hallway wall to enable a person crawling below a level of smoke in the hallway to be visually guided to an exit door.

Abstract: Described herein are apparatus, method, and system for reducing clock-to-output delay of a sequential logic unit in a processor. The apparatus comprises a sequential unit including: a data path, to receive an input signal, including logic gates to operate on a first power supply level, the data path to generate an output signal; and a clock path including logic gates to operate on a second power supply level, the logic gates of the clock path to sample the input signal using a sampling signal to generate the output signal, wherein the second power supply level is higher than the first power supply level. The apparatus improves (i.e. reduces) setup time of the sequential unit and allows the processor to operate at minimum operating voltage (Vmin) without degrading performance of the sequential unit.

Abstract: An LED lighting device with backup switching function has a device main body, configured with at least one LED fitting part and one power supply part. At least one LED component is configured on the LED fitting part and has a main lighting circuit. A backup lighting circuit is fitted inside the same LED component as the main lighting circuit or inside a different LED component. A backup switching processor is electrically connected to and fitted between the main lighting circuit and backup lighting circuit and is connected to the power supply. Based on the automatic detection function of the backup switching processor, in case of short circuit or broken circuit of the main lighting circuit, the switching processor will automatically switch to the backup lighting circuit and maintain continuous lighting of the LED component, and consequently increase the lifecycle of the LED component and reduce repair frequency and cost.

Abstract: A lighting system, a lighting unit and a method for controlling a plurality of light sources are described. A lighting system comprises an intelligent electrical current supply 12 to supply an electrical current with modulated command data. A plurality of lighting units 4, 6, 8 are connected in series to the current supply 12. Each lighting unit comprises a light source 22, a controllable bypassing switch 24 to selectively bypass the light source and a control unit 26. The control unit receives the modulated command data and controls the bypassing switch 24 accordingly.

Abstract: A novel vehicle lighting control circuit for reducing the light intensity of a vehicle lighting element via pulse width modulation. A pulse width modulation adjuster is provided for producing a pulse width modulation control signal in order to operate the vehicle lighting element at a reduced light intensity. Such examples for use of the present invention include, but are not limited to, operation of: high beams at a low beam light intensity; daytime running lamps (DRLs); power balancing functions; and emergency lights.

Abstract: A system for use in monitoring the operation of motorcycle brake and tail lights is disclosed which, upon determination that a brake or tail light is not operating properly to provide a warning light signal, automatically provides an alternate warning light signal which is highly visible to traffic following the motorcycle. Current sensors are used to determine whether electricity is flowing through the brake light and tail light circuits, or, alternately, whether there is an open circuit condition in one or both circuits which is indicative of a burned-out bulb. If the tail light burns out, control switching elements are used to supply current to the left rear turn signal light, the right rear turn signal light, and the brake light to illuminate them, thereby providing a warning signal at the rear of the motorcycle.

Abstract: A ballast for lighting an auxiliary source of illumination whenever a primary source of illumination fails to ignite. The auxiliary source of illumination is effectively turned OFF by placing a short circuit thereacross whenever the primary source of illumination is lit. The short circuit is removed whenever the primary source of illumination fails to reach a predetermined level of illumination thereby permitting current to flow through and light the auxiliary source of light. The ballast also includes a power factor correction device for increasing the ballast power factor when the primary source of light reaches a predetermined level of illumination.

Abstract: A lighting system having a primary light source and an emergency lamp. The emergency lamp is turned on and remains on upon failure or removal from the system of the primary light source. The system also includes a control device for sensing when the voltage across the primary light source rises above a predetermined level in determining when to turn on the emergency lamp.

Abstract: A lighting circuit for a vehicle illuminates a back-up lighting element when a primary lighting element fails. Both lighting elements may be installed in a single housing, such as a headlight assembly. A dashboard switch places the primary lighting element in circuit with the vehicle power supply. In preferred form, a low-resistance coil is series connected with the primary lighting element. The coil is magnetically coupled to switching elements in a low-current flow path between power supply terminals. Switching elements in the low-current flow path control a low-power mechanical switch that places the back-up lighting element in circuit with the power supply. If the primary element fails, the absence of current through the coil triggers the switching elements to close the mechanical switch and to illuminate the back-up element. The dashboard carries a graphic representation of the vehicle. A light emitting diode on the representation is illuminated when the primary element fails to .pi.

Abstract: The present invention provides a Control Module 15 for controlling a dual filament bulb, in particular aircraft reading lamps, so as to detect the failure of one filament and energize the other filament. The Control Module 15 also has provisions for detection of bulbs that have only one or no operable filament(s) by activating an indicator (Light Emitting Diode) or connection to a test switch that will command the Module to activate bulbs that have two operable filaments only. The Control Module 15 consists of a solid state circuit made up of triacs, resistors, capacitor, diodes and fuse all packaged in a small printed circuit board. Interface between the Module and dual filament bulb, indicator or test switch is easily accomplished by a small connector on the Control Module 15.

Abstract: There is provided a luminaire primarily for use with exit signs and other emergency-type lighting comprising a series string of low-voltage, extremely long-life bulbs positioned within an enclosure for protection and electrically connected to a standard base whereby luminaires having lives of 10 to 30 years may replace standard bulbs without the requirement of retrofitting.

Abstract: A self-relamping clearance/marker light assembly includes a pair of lamps connected to a proving ring switch. A primary one of the almps is lighted and the switch prevents current flow through a secondary one of the lamps until the primary lamp burns out. The lamps are operated at a derated voltage to increase life and a small compensating lamp provides the necessary additional illumination lost through the reduced voltage operation of the primary and secondary lamps. The lamps are mounted for isolation from high frequency vibration and shock impacts using the lamp lead wires to form part of the shock mounting.

Abstract: This adapter has a housing containing an automatic electrical switching circuit, a plug for connecting the circuit to an external A.C. power source, and sockets for mounting primary and standby lamps on the housing in circuit with the switching circuit. The circuit includes a conventional rectifier bridge and a transistor which is normally biased off so that the standby lamp is off, when the primary lamp lights. When the primary lamp goes off (burns out), the transistor conducts and the standby lamp is automatically turned on. When the primary lamp again operates the transistor is again biased off and the standby lamp is automatically turned off. A signal lamp in the switch circuit lights when the standby lamp is on. Motors or other power consuming devices may be substituted for the lamps.

Abstract: A multiple headlamp system for vehicles, comprising at least two individual lamps having their filaments connected in electrical series. This permits the use of shorter filaments and hence smaller diameter reflector lamps, without loss of optical control or reflector efficiency, for use in modern cars having low-profile front ends for providing improved aerodynamic streamlining. In a preferred embodiment, a vehicle is provided with two sets of headlamps, each set comprising a pair of individual headlamps each containing a filament at the focal point of the reflector for achieving maximum optical control, and means for connecting the filaments of each pair in electrical series across the vehicle's battery, one lamp of the pair being designed to provide a narrow-beam "punch" light for distant viewing, and the other lamp of the pair being designed to provide a wide-angle beam "spread" light for general viewing.

Abstract: A vehicle lighting system of the type employing dim or low-beam headlights and bright or high-beam headlights is provided with continual sensing of the operativeness of a selected headlight to cause the automatic substitution of a non-selected headlight in the event of failure of the selected headlight.

Abstract: A multiple lamp system for use with fiber optic light guide for automatically switching from a main lamp to a standby lamp upon failure of the former. A solenoid is employed with the inductor in the circuit of the main lamp to overcome the bias of the switch in the standby lamp circuit to keep the former open. When the main lamp fails causing interruption of current flow, the switch closes thereby permitting energization of the standby lamp. An indicator is provided to show which lamp is functioning.

Abstract: A three-terminal thermal switch having a common connector arm biased against a terminal of fusible material. When the terminal is softened or melted by current, the connector arm is released and moves into contact against a second terminal. Positioned in the base of a long-life dual-filament incandescent light bulb, the switch causes one filament to be energized until it burns out, and then connects the other filament to be energized.

Abstract: An improved dual polarity substitution circuit for energizing a secondary load, such as an incandescent lamp, upon failure of a primary load. Dual polarity is achieved through the use of parallel PNP and NPN transistors, one of which conducts so long as the primary load is functional. Upon failure of the primary load and interruption of current flow in the conducting one of the transistors, a bidirectional switch such as a triac is fired to energize the secondary load.

Abstract: A safety circuit is provided for parallel connected electrical loads. The headlight circuit of an automobile or other vehicle is an important application for the circuit. In the circuit a reversely polled control rectifier is in a parallel conductor subcircuit to the bright lamp filament of the headlight. The gate of the control rectifier is connected to a conductor of the dim lamp filament of the headlight. The control rectifier presents an open circuit when both of the lamps are operable but is adapted to connect the bright lamp filament through a resistor and a diode when the dim lamp filament of the headlight fails.

Abstract: A voltage detecting means, such as a voltage winding, a zener diode or the like, is connected across a power source and is operative when the voltage applied thereto exceeds a predetermined value owing to a disconnection of a main lamp also connected across said power source. A disconnection indicating means, such as a lamp, is connected to the voltage detecting means and is energized when the volage detecting means operates.

Abstract: This invention pertains to an emergency lighting circuit that operates with a high pressure, gaseous-discharge lamp and associated ballast. When the gaseous-discharge lamp goes out, after once being ignited, sufficient current is supplied to an incandescent light or lights to maintain illumination to the area normally illuminated by the lamp. The device for providing this current may vary, but generally incorporates a voltage breakdown means that receives higher voltage from the ballast when there is failure of the gaseous-discharge lamp than when the arc therein is struck. A preferred embodiment also lights the incandescent lights during initial warm-up of the gaseous-discharge lamp. The incandescent lights may also be used in a cold environment to maintain the gaseous-discharge lamp sufficiently above an ambient temperature level to make possible initial striking of the arc in the lamp when ambient temperature conditions might otherwise prevent it.

Abstract: A control circuit for a light projection system for energizing a spare lamp when the circuit detects failure of a main lamp. A pair of input lines apply an alternating-current voltage source to the circuit, to the main lamp and to a spare lamp which is substantially in parallel connection with the main lamp. A switch is in series connection with the main and spare lamp for selectively energizing one of the lamps. Current sensing means, generally a resistor, in series connection with the switch and the lamps, senses the current through the main lamp thereby dropping a small portion of the voltage source. A pair of opposite polarity voltage references are established by rectifying the voltage dropped across the current sensing resistor and by rectifying the voltage across the input lines of the voltage source.

Abstract: An emergency lighting system, employing a mercury lamp and an incandescent lamp, and relay circuits for turning on the incandescent lamp in substitution for the mercury lamp, when the light output of the latter is limited, during either cold start or hot start, and for turning off the incandescent lamp without chatter.

Abstract: An electrical receptacle device having a main lamp socket and an auxiliary socket adapted to receive an auxiliary lamp operative only upon failure of a main lamp in a main lamp socket. The two sockets are arranged in aligned opposition in a common housing providing a heating chamber in spaced, parallel relation with respect to the screw base ferrules along one side thereof. A slightly curved, elongated bi-metallic switch element extends along and within the heating chamber, having one end affixed to the main lamp socket ferrule and the other end positioned for movement in and out of contact, selectively, with the auxiliary lamp socket in response to temperature conditions in the heating chamber effected by non-operation and operation, respectively of a main lamp in the main lamp socket.