Abstract: The invention relates to an illumination apparatus having at least a first and a second illumination unit, wherein each of the illumination units comprises an LED arrangement and a supply device for supplying the LED arrangement, each of the LED arrangements comprising at least one LED group having a multiplicity of LEDs and the LED groups of the LED arrangements being similar, and having a control device for driving the at least two illumination units with a common nominal dim drive value, the nominal dim drive value driving the illumination units in such a way that the similar LED groups of the illumination units are operated in a dim mode. The invention also relates to a method for operating the illumination apparatus in the dim mode.

Abstract: A lighting device has a first panel, which has an underside and an upper side, and a plurality of lighting elements which illuminate the first panel from the underside. The first panel has a plurality of transparent and non-transparent elements which are arranged one adjacent to the other in an alternating fashion and which each extend completely from the underside to the upper side. The lighting elements are controlled by a control device which is designed to bring about a predefinable spatial brightness profile in a space on the upper side of the first panel.

Abstract: The discharge lamp lighting device in accordance with the present invention includes a controller configured to perform an abnormality judgment process of judging whether or not abnormality has occurred based on a measured value of a driving voltage defined as an AC voltage applied to a discharge lamp. The controller is configured to, in the abnormality judgment process, judge whether or not an asymmetric state in which the driving voltage lacks symmetry has occurred over a predetermined period. The controller is configured to, upon concluding that the asymmetric state has occurred over the predetermined period, conclude that the abnormality has occurred.

Abstract: Systems and methods for providing adequate lighting and sighting for a bicycle are disclosed. A lighting system that includes an illumination ring configured to be coupled to a wheel is also disclosed. The illumination ring is configured to simultaneously project light forward and to the side of a front wheel and to project light rearward of and to the side of a rear wheel. The illumination ring may be mounted to or integrated with the bicycle wheel. Methods of controlling light sources on the illumination ring are also disclosed.

Abstract: The invention relates to a device for operating a lamp, in particular in a vehicle, wherein the lamp is coupled to a controller for energy-related supply of the lamp, and a data channel is present between the controller and the control unit. It is inventively provided that the controller and the control unit exchange characteristic data of the lamp, in particular current parameter data, temperature protection data, socket current data, or the like via the data channel, and the controller has an indicator with an indicator value, wherein in the instant of a first initialization of the controller, the characteristic data can be transmitted from the controller to the control unit depending on the indicator value.

Abstract: A controller controls an illumination device of a motor vehicle including at least one light source. The controller includes at least one first stage that provides electric energy for supplying power to the illumination device. At least one second stage forwards the electric energy to the light source. The first stage includes intelligence for controlling the illuminating device, a first supplier for supplying the illumination device with control signals, a generator for generating a constant intermediate voltage, and a second supplier for supplying the second stage with the intermediate voltage. The second stage includes a converter for conversion of the intermediate voltage into a supply voltage suitable for supplying the power to the light source, a third supplier for supplying the light source with the supply voltage, and a mechanism for controlling the light source in dependency on the control signals. Also, an illumination device for a motor vehicle includes the controller.

Abstract: A vehicular LED lamp includes a mounting seat and a plurality of LED light-emitting units mounted on the mounting seat. Each LED light-emitting unit includes a carrier plate having inner and outer surfaces, a circuit board engaged on the outer surface of the carrier plate, and at least one LED mounted on the circuit board and in contact with the outer surface of the carrier plate. The mounting seat includes a plurality of mounting grooves each having a bottom wall and two side walls with inclined sections. The LED light-emitting units are received in the mounting grooves of the mounting seat, with the inner surface of each carrier plate in contact with the bottom wall of an associated mounting groove, with two sides of each carrier plate abutting the inclined sections of the associated mounting groove.

Abstract: A vehicle LED lighting device includes a drive control means 51 includes an abnormality detection means 60 detecting a disconnection or short-circuit abnormality of the LED lamp, the abnormality detection means 60 includes a current detection unit 61 detecting the value of a current flowing through the LED lamps 20 and 30 when the LED lamps 20 and 30 are driven by the drive control means 51, a comparison unit 62 comparing the current value detected by the current detection unit 61 with a predetermined abnormality determination value, and a determination value switching unit 63 switching the abnormality determination value in accordance with variation of a power supply voltage of the vehicle, and whether or not there is the disconnection or short-circuit abnormality is judged based on the abnormality determination value switched by the determination value switching unit 63 and the detected current value.

Abstract: A vehicle instrument configured so that turning on and off the light sources without depending on inputted vehicle information enables the instrument to be illuminated in a visually effective manner. The instrument is provided with: input circuits into which vehicle information is inputted as electric signals and which are provided with resistors connected to light sources relating to the vehicle information; electric-potential adjustment circuits for adjusting the electric potentials of lines of wiring between the input circuits and the light sources on the basis of control signals from a controller and eliminating influence on the light sources from the vehicle information; and light source control circuits which, when influence on the light sources is eliminated by the electric-potential adjustment circuits, operate and visualize turning on and off of the light sources on basis of the control signals from the controller.

Abstract: A vehicle control device mounted on a vehicle for performing communication with a mobile device and performing predetermined control in accordance with communication contents with the mobile device, having a locking operation unit that locks or unlocks doors of the vehicle, interior signal transmitting and receiving units that detect a position of the mobile device left in an interior of the vehicle in a case where a locking operation is performed by the locking operation unit, and an interior lamp drive control unit that lights an interior lamp among a plurality of interior lamps provided in the interior of the vehicle, the interior lamp being close to the position of the mobile device based on information of the position detected by the interior signal transmitting and receiving units.

Abstract: An exterior lighting system for a vehicle is disclosed. The lighting system may include a plurality of lights provided proximate the wheel-wheels of the vehicle. The plurality of lights may be illuminated upon a brake pedal of the vehicle being depressed, a turn signal lever of the vehicle being activated, or upon a driver entering a desired setting into an operator interface of the system. The lighting system may be used as a safety feature to provide approaching vehicles better warning of a braking, slowing, or turning vehicle. The lighting system may also be used during roadside repair to warn other vehicles and/or to provide illumination for the repair. The lighting system may also be used for entertainment or accessorizing purposes enabling the user to select from a plurality of lighting sequences stored in the memory of the system.

Abstract: A luminous radiator cover device includes: alighting cover unit (2) including a looped frame (3) mounted to a front side of a vehicle (900), multiple hollow light-transmissive ribs (4) each disposed in and connected to the frame (3), and multiple lighting units (5) each disposed in a corresponding light-transmissive rib (4); and a control unit (6) connected electrically to the lighting units (5) of the lighting cover unit (2). The control unit (6) is operable to control the lighting units (5) of the lighting cover unit (2) to operate in a lighting mode, where lighting of each lighting unit (5) is varied in response to sound in the vehicle (900).

Abstract: Power conversion apparatus includes a converter circuit, a control circuit, a simulation circuit and a sense circuit. The converter circuit includes a magnetic device for power conversion and a switching device, and is configured to convert power from a power supply into direct current power. The control circuit is configured to supply the converter circuit with a high frequency signal for turning the switching device on and off. The simulation circuit is configured to produce a simulation signal that simulates state or change of magnetic flux of the magnetic device. The sense circuit is configured to produce a signal which corresponds to at least one of the input and output of the converter circuit and is superposed on the simulation signal to form a superposed signal. The control circuit defines an on-period of the high frequency signal based on the superposed signal.

Abstract: A lighting control device for a vehicle according to the embodiment includes a display unit; a control device reception unit which receives non-lighted state information of a light source of a lighting system; and a control device control circuit which changes a display state of the display unit based on the non-lighted state information.

Abstract: Provided is a wire harness assembly configured to be lightweight while reducing burden on a first control means, and a lighting unit comprising the wire harness assembly. A wire harness assembly for connecting a plurality of lighting loads to a control unit that outputs a control signal for controlling the plurality of lighting loads independently is provided with: a first wire harness connected to the control unit and including a power-supply line, a ground line, and a signal line for multiplex transmission of the control signal output from the control unit to each of the lighting loads; a second wire harness including a first electric line commonly connected to one ends of the plurality of lighting loads, and a plurality of second electric lines connected to the other ends of the plurality of lighting loads individually; and a relay connector connecting the first wire harness to the second wire harness.

Abstract: A multi-function vehicle light assembly (MVLA) that incorporates in a single enclosure a plurality of LED modules. Each module produces a white light that indicates that a vehicle is in reverse, an amber light that indicates that a vehicle is making a right or a left turn, and a red light that functions as a vehicle tail-light and to indicate that the brakes are being applied. Two embodiments are disclosed, in the first embodiment the plurality of LED modules directly produce a set of white, amber and red lights. In the second embodiment an LED module is utilized that includes blue, green and red LEDs that are selectively combined by an LED control circuit to produce the white, amber and red lights. Each embodiment also includes a set of control units for selecting which of the input signal lines are to be activated.

Abstract: A variable color light system includes multiple dual color light emitting diodes (LED's) arranged in a light bar. The dual LED's are arranged with a common cathode and two anodes. The light system includes a switch that controls the power to the light system. The system is controlled to power a first anode, a second anode, or neither anodes. When the first anode is powered, the dual LED's emit a first color. When the second anode is powered, the dual LED's emit a second color. The light system is LED driven. The dual LED light system can be used in a light bar that can be used on a vehicle, an off-road vehicle, a recreational vehicle, or a boat.

Abstract: A vehicle signal light assembly includes: at least one color mixing light source; a support element configured to support the at least one color mixing light source on a vehicle as a signal light; and a controller configured to selectively drive each color mixing light source to generate light of a selected visually perceived color based on a received control signal. In some such embodiments, each color mixing light source of the vehicle signal light assembly comprises a plurality of light emitting diodes (LEDs) of at least two constituent colors. In some such embodiments, the controller is configured to operate each color mixing light source of the vehicle signal light assembly using time domain multiplexing (TDM) to generate the light of the selected visually perceived color. In some such embodiments, the vehicle signal light assembly comprises a taillight assembly. In some of the embodiments, the vehicle light assembly comprises an ambient or auxiliary lighting, or a dashboard lighting assembly.

Abstract: A vehicle headlamp apparatus is provided. The vehicle headlamp apparatus includes a first lamp configured to selectively produce a first high beam light distribution pattern and an infrared light distribution pattern, a second lamp configured to selectively produce a second high beam light distribution pattern and a low beam light distribution pattern, a vehicle detector which detects a vehicle running ahead, and a condition-dependent selection controller which controls the first and second lamps. The condition-dependent selection controller controls the second lamp to produce the low beam light distribution pattern when the vehicle detector detects a vehicle and to produce the second high beam light distribution pattern when the vehicle detector detects no vehicle. The condition-dependent selection controller controls the first lamp to produce the infrared light distribution pattern, irrespective of whether the vehicle detector detects a vehicle.

Abstract: A light emitting diode (LED) lighting fixture has monitoring and control circuits that sense when a freezing condition is present that could result in ice and/or snow accumulation on a lens of the LED lighting fixture, thereby reducing the light output therefrom. Heat may be supplied to the lens from a transparent resistive coating thereon, an internal space heater and/or increased power dissipate from the LEDs.

Abstract: A discharge lamp lighting device light which drives a discharge lamp with an alternating power includes a DC-DC converter, an inverter, a voltage detector which detects an output voltage of the DC-DC converter, and a current detector which detects an output current of the DC-DC converter. The discharge lamp lighting device light further includes a controller controlling a switching frequency of the DC-DC converter according to a detection value of at least one of the voltage detector and the current detector; and a PWM ON signal controller increasing a DC power by lengthening an ON duty of a PWM signal during a predetermined period after a start of polarity inversion of the alternating power. When the voltage detector and/or the current detector detects a detection value, the controller changes an increase amount of the DC power according to the detection value.

Abstract: A transit vehicle lighting system has a plurality of LED-based lighting fixtures for providing interior illumination. A control network comprises a plurality of slave nodes for controlling the LED-based lighting fixtures, and a master node for controlling the slave nodes. The master node may be connected to the slave nodes by a combined power/communication bus in a daisy chain fashion. The slave node may include a power regulator and a controller for providing a target current command to the power regulator, and may adjust the target current based upon temperature measurements or a recorded age of the LEDs. An optical sensor may provide automatic dimming. A reduced number of LEDs may be used in an emergency mode. The lighting fixture may include a ceiling panel fixture and a riser panel attachable by way of a hinge mechanism.

Abstract: The present invention relates to an automotive device which will control the operation of optional tail lights equipment by monitoring level of current in any motor vehicle OEM tail lights electrical circuit. The device comprises a plurality of current sensor modules, each including a current sensor and a RF transmitter antenna, and a brain module including a controller, a RF receiver antenna, and a power source. The current sensors are placed on top of OEM tail lights wire to monitor the current level and transmit such information to brain module. When the level of current detected by any current sensor raises above certain level the controller closes electrical circuit of the optional tail light equipment dedicated to that particular Sensor; when the level of Current lowers under certain level, the controller opens the electrical circuit of the optional tail light equipment dedicated to that particular Sensor.

Abstract: A lighting system which may provide supplemental lighting for the stairs of a vehicle under conditions of low ambient lighting. Supplemental lighting may be provided for at least a period of time desired for ingress and/or egress of the operator.

Abstract: The present invention provides a vehicle lighting device that can set a wide output current without replacing a component such as a coli. An output current setting device 7 sets an output current setting signal 8 in such a manner that an output current 5 in accordance with a luminous flux of an LED 2 is outputted. The output current setting signal 8 is supplied to a frequency adjusting component 3a and an output current detecting component 3b. The frequency adjusting component 3a generates a triangle wave of a frequency based upon the output current setting signal 8, and supplies the triangle wave to an output adjusting-signal generating component 3c. The output adjusting-signal generating component 3c compares the triangle wave with a signal voltage that is outputted from the output current detecting component 3b to generate an output adjusting signal 6, which is supplied to a switching element 30.

Abstract: Systems and methods for providing adequate lighting and sighting for a bicycle are disclosed. A lighting system that includes an illumination ring configured to be coupled to a wheel is also disclosed. The illumination ring is configured to simultaneously project light forward and to the side of a front wheel and to project light rearward of and to the side of a rear wheel. The illumination ring may be mounted to or integrated with the bicycle wheel. Methods of controlling light sources on the illumination ring are also disclosed.

Abstract: A control system for vehicle headlights includes a navigation device and a control unit which controls the illumination characteristics of the headlights depending on geographic location information received by the navigation device. The illumination characteristics are adapted in compliance with predefined illumination settings if the acquired geographic location information shows that the vehicle headlights are being operated on public roads. The illumination characteristics are adapted with further consideration of illumination settings specified by the driver if the location information shows that the vehicle headlights are being operated on non-public roads.

Abstract: A vehicle dome and reading light assembly for a vehicle includes a lighting device assembled to the interior of the vehicle and capable of generating plural light colors. A first switch is actuatable to cause the lighting device to generate a first color light and a first light intensity to serve as a dome lamp. A second switch is actuatable to cause the lighting device to generate a second color light at a second light intensity to serve as a map or reading lamp.

Abstract: Methods, systems, devices and/or apparatus related to lighting systems, and, specifically, to LED lighting systems for vehicles. One example provides a lighting system that includes a power control component, a wire harness, and a light emitting diode component. The power control component may be in electrical communication with a power supply. The power control component may receive an input voltage from the power supply, adjust the input voltage to generate an output voltage, and output the output voltage. The wire harness may be in electrical communication with the power control component. The light emitting diode light component may be in electrical communication with the wire harness, and may include a plurality of light emitting diodes electrically coupled in a parallel configuration via a plurality of wires, each of the plurality of wires being substantially shaped as a wave.

Abstract: A vehicle information transmission device includes: a display device that displays light in a first mode at a position of a vehicle body, at which visual recognition of a certain object is prompted, when the visual recognition is prompted and that displays light in a second mode different from the first mode on the vehicle body when the visual recognition is not prompted or when the visual recognition is prompted; and a control unit that adjusts light in the second mode on the basis of light in the first mode when the visual recognition is prompted.

Abstract: A luminous device includes at least one radiation-emitting semiconductor chip including at least two emission regions arranged spaced apart in a lateral direction, wherein each emission region includes at least one active zone that emits electromagnetic radiation; and a drive device that operates the emission regions.

Abstract: A solar light bar includes a battery isolator adapted to be connected between a bus and a vehicle charging system for isolating a vehicle battery from the bus and for selectively connecting the bus to the charging system. A light source switch connects the light source and the bus for selectively electrically connecting the light source to the bus. When the light source switch is closed, the light source is energized by electricity from at least one of the solar panel, the charging system and the auxiliary battery. When the light source switch is open, the light source is isolated from the bus. The auxiliary battery is adapted to be selectively charged by electricity from at least one of the solar panel and the charging system.

Abstract: Lighting devices for a vehicle are disclosed that can include a light emitting diode and control circuitry for the light emitting diode. Also disclosed are circuits for a light emitting diode. Additionally, a method of forming a lighting device is disclosed. The lighting device, circuits, and method can be used, for example, to illuminate the interior of a vehicle.

Abstract: A control device includes a plurality of LED arrays connected in parallel to one another, each of the plurality of LED arrays including one or more LEDs connected in series and a resistance element connected in series to the LEDs, a voltage application circuit that applies a voltage to the plurality of LED arrays, a switching element disposed between the plurality of LED arrays and a ground, a voltage detection circuit having an end connected between the switching element and the plurality of LED arrays, a capacitor having an end connected between the switching element and the plurality of LED arrays, and another end connected to the ground, and a control circuit that controls the voltage outputted from the voltage application circuit and switching of conduction states of the switching element, and reads a voltage from the voltage detection circuit.

Abstract: Control system and method for automatically controlling headlights of a vehicle includes an optical system for imaging external sources of light within a predetermined field of view and an image processing system for processing images from the optical system and providing a control signal for controlling the headlights as a function of the processed images. Processing the images may entail identifying a source of radiation in the images, the control signal being provided to dim the headlights when a source of radiation in the images is identified as a headlight or taillight of another vehicle. To this end, the image processing system may include a trained pattern recognition system for processing the images to identify the source of radiation, e.g., a pattern recognition algorithm generated from data of possible sources of radiation including headlights and taillights of vehicles and patterns of received radiation from the possible sources.

Abstract: A head light for a motor vehicle has a light source for generating a beam of light as well as a electronic beam steering module for steering the beam of light and/or a electronic beam shaping module for shaping the beam of light, wherein the head light has a light filter for eliminating at least the substantial portion of red light from the light generated by means of the light source.

Abstract: A vehicular LED lamp monitoring/controlling system includes a vehicular LED lamp having first and second LEDs. A selection/control unit is connected to and controls separate activation of the first and second LEDs and is connected to a malfunction detecting unit that detects operation of the first and second LEDs. The second LED is activated when the first LED operates abnormally. A power control unit can send a control signal to the selection/control unit to control luminance of each of the first and second LEDs. A vehicle speed monitoring unit connected to the power control unit reads a speed of a vehicle on which the vehicular LED lamp is mounted. When the vehicle is moving, the first or second LED provides normal luminance. When the vehicle is not moving, the first or second LED provides reduced luminance.

Abstract: A process and a device for controlling a plurality of LED assemblies of an automotive vehicle, each LED assembly (Gi) executing a specific lighting/signalling function. The electrical power level (Pi) delivered by the electrical source is modulated according to distinct power levels (Pi) with relation to the function associated with each LED assembly (Gi) and temporary multiplexing is executed in order to successively transmit the distinct power levels (Pi) to the assemblies (Gi) over a multiplexing period (Tmux). Demultiplexing is effected and each distinct electrical power level (Pi) is selectively delivered to the LED assembly (Gi) concerned.

Abstract: The invention relates to a LED collimator element for a vehicle headlight with a low-beam function, which emits at least visible light of one color from at least one region of a light source.

Abstract: A device is provided for controlling a light function of a headlight of a vehicle and a method is provided for controlling the light functions of headlights of a vehicle that includes, but is not limited to at least two different light functions are set by at least one drive device and the drive device is activated via a light control unit. The light control unit communicates with a supervision authority, parameters stored in the supervision authority predefining the dynamic behavior of the light functions.

Abstract: A roadside-vehicle cooperative illumination system in which a headlight of a vehicle and a road illumination lamp can be controlled cooperatively through communications between an in-vehicle apparatus and a roadside apparatus. For example, when power consumption of the headlight has to be reduced, an in-vehicle apparatus side arbiter transmits a request to the roadside apparatus for increase illumination of the road illumination lamp. A roadside apparatus side arbiter determines whether or not to accept the request from the in-vehicle apparatus, and a roadside apparatus side controller controls the road illumination lamp according to the determination of the roadside apparatus side arbiter. This enables the road illumination lamp to be controlled cooperatively so that illumination of the road illumination lamp can compensate for deficiencies in illumination of the headlight, which leads to enhancement of vehicle driver's convenience and ensuring of safety.

Abstract: A light quantity control apparatus, which controls light quantity of a light of a vehicle, includes a traffic-jam-information obtaining unit obtaining traffic-jam-information including information on positions and on presence/absence of a traffic jam, a vehicle-position obtaining unit obtaining a position of a vehicle, a traffic-jam identifying unit identifying whether the vehicle is in a traffic jam based on the traffic-jam-information and the position of the vehicle, a traffic-jam-time light quantity control unit decreasing the light quantity compared with a normal time if the vehicle is in a traffic jam, an urban-district obtaining unit obtaining information on whether or not the vehicle is in an urban district or near an intersection, and an urban-district-traveling-time light quantity control unit decreasing the light quantity compared with a case where the vehicle is in an area other than urban districts and intersections if the vehicle is in the urban district or near an intersection.

Abstract: A lamp and lamp driver are disclosed, in which single intensity marker lamps that are desired to be flashed can be connected to a lamp driver employing an exclusive OR (XOR) logic circuit. In one application, this lamp driver is coupled to a vehicle turn function wire and marker function wire, and a plurality of marker lamps in a row can be of the same style, but one lamp can be flashed in the row of marker lamps. In some embodiments, if all of the marker lamps are on, the lamp being driven by the XOR driver circuit will flash out of sequence with the turn signal flash. If all of the marker lamps are off, the lamp being driven by the XOR driver circuit will flash in sequence with the turn signal flash. Other embodiments are disclosed.

Abstract: An aircraft cabin lighting kit includes: at least one lighting unit configured for installation in an aircraft cabin; a driving/dimming module generating output signals for controlling illumination of the at least one lighting unit according to command signals from a cabin management system; and at least one wire assembly interfacing the driving/dimming module with a power bus for receiving operational power, and a communication bus for receiving the command signals and for communicating the output signals to the at least one lighting unit. The present aircraft cabin lighting kit is certified by a governmental aviation-regulating body for installation in multiple aircraft.

Abstract: Light for motor vehicles and the like provided with a lighting device comprising a pair of power supply lines flowed through by a primary supplying current, two or more lighting branches each comprising one or more light sources adapted for being flowed through by a secondary supplying current; and an electronic control circuit configured to determine the secondary current flowing through each lighting branch; limit the primary supplying current to a predetermined minimum value when the secondary current flowing through at least one of said lighting branches is lesser than a predetermined threshold current; control the simultaneous transition of the light sources from a pre-lighting state to a complete-lighting state, when each of the secondary currents flowing through the lighting branches is greater than or equal to the predetermined current threshold.

Abstract: To satisfy the need for refitting the lighting of a vehicle without the need to modify the controlling system of the vehicle, the present invention proposes a lighting system which comprises an electrical element (110), configured to consume the received power and incapable of emitting light; a light source (130); and a controller (120), configured to receive a first signal indicating the working status of the electrical element (110) and control the light source (130) generating a first light and a second light, respectively, based on the first signal. By utilizing the signal indicating the working status of the electrical element (110), which element is used to replace another automotive lamp, the controller can control the light source (130) to mimic said another automotive lamp while performing its original function.

Abstract: An exterior lighting system for a vehicle is disclosed. The lighting system may include a plurality of lights provided proximate the wheel-wheels of the vehicle. The plurality of lights may be illuminated upon a brake pedal of the vehicle being depressed, a turn signal lever of the vehicle being activated, or upon a driver entering a desired setting into an operator interface of the system. The lighting system may be used as a safety feature to provide approaching vehicles better warning of a braking, slowing, or turning vehicle. The lighting system may also be used during roadside repair to warn other vehicles and/or to provide illumination for the repair. The lighting system may also be used for entertainment or accessorizing purposes enabling the user to select from a plurality of lighting sequences stored in the memory of the system.

Abstract: A vehicle lamp includes: an infrared light semiconductor light source which emits infrared light; a white light semiconductor light source which emits white light; and a control unit including: a current supply circuit which supplies a light source driving current to each of the infrared light semiconductor light source and the white light semiconductor light source; and a light source abnormality detecting unit which detects abnormality of the white light semiconductor light source and stops a driving operation of the infrared light semiconductor light source when the abnormality is detected.

Abstract: A motor vehicle electrical power system includes a light source powered from an electrical power source. At key on the light source is tested to determine operational readiness and the type of the light source. At key on the switch is cycled to apply a pulse width modulated energization to the light source. A reference copy of the pulse width modulated signal is available. A comparator having first and second inputs provides a comparison of the pulse width modulated signal applied to the light source and reference. Variation in the rate of change of voltage across the light source may be compared with the reference to characterize the light source as a light emitting diode or another type of source, usually an incandescent bulb.

Abstract: A vehicle lighting device according to the present invention is configured in such a manner that a current that is supplied to a light emitting element that serves as a light source can be controlled with low power consumption in accordance with either of a voltage change in input power supply and a change in ambient temperature. This vehicle lighting device is configured in such a manner as to take out a reference voltage that is input to a switching controller 5 from a voltage dividing resistor R2 that is connected between a constant voltage source Vcc and a ground terminal GND. A current control circuit 10C for voltage change is provided to between an input power supply Vin and the ground terminal GND. Further, a current control circuit 10A for temperature change is provided to between the constant voltage source Vcc and the ground terminal GND.