A light, in particular for testing workpiece surfaces using a fluorescent marking device, which light has at least two lighting elements that emit electromagnetic radiation with different wavelength ranges. The intensity with which the lighting element irradiates can be adjusted separately for at least one of the lighting elements. Expediently, the light is configured to increase or reduce the intensity of at least one of the lighting elements and at the same time to keep the intensity of at least one other of the lighting elements constant, or to reduce it or increase it in the opposite way to the first-mentioned lighting element. The light is configured to adjust the intensity at such a speed that the human eye can adapt to a change in the intensity during the adjustment without adverse effects on the person's sight.

A linear light-emitting diode (LED) lamp comprising a normally-operated portion and an emergency-operated portion is used to replace a luminaire operated only in a normal mode with alternate-current (AC) mains. The normally-operated portion comprises a fly-back converter whereas the emergency-operated portion comprises a rechargeable battery, a bidirectional circuit, a boost converter, a self-diagnostic circuit, and a control circuit. The linear LED lamp can auto-switch from the normal mode to an emergency mode according to availability of the AC mains and whether a rechargeable battery test is initiated. The bidirectional circuit is configured to convey a forward electric current and a reverse electric current to and from the rechargeable battery, respectively. The self-diagnostic circuit is configured to provide multiple sequences and to auto-evaluate battery performance according to the multiple sequences. During an auto-evaluation period, a terminal voltage on the rechargeable battery is examined with test results displayed in a status indicator.

A system for controlling LED lightbox power supplies, comprises the lightbox supplies disposed inside a lightbox and correspondingly connected with LED light bars one by one. All the lightbox power supplies are connected in series with one another via a 485 communication bus. Meanwhile, a wireless communication device connected in series with the lightbox power supplies is further mounted inside the lightbox. A gateway device for wirelessly connecting with the wireless communication device and uploading data acquired to a cloud server, is arranged outside the lightbox. A sensor set connected in a wired manner with the wireless communication device is arranged on an outer wall of the lightbox.

A lamp for a vehicle or other object that includes multiple functions. In one aspect, the lamp includes a first circuit for emitting a first color light (such as red light), and at least a second circuit for emitting a second color of light (such as amber light). In another aspect, the lamp optionally includes a microcontroller that may be programmed to control the activation of the different colored lamp circuits based on lamp location information, and based on an operating mode.

A vehicle LED lighting outage detection circuit is disclosed for detecting a fault in the LED light and automatically increasing the power drawn from the light power supply in response to the fault. A complementary detection circuit is also disclosed for detecting the increased power draw and signaling a fault to an operator. The increased power draw can be selected to be in the form of a pulse that settles to a lower power draw state after a time to avoid excessive and wasteful power draw. The system can be mounted in a vehicle and, more particularly, to a semi-tractor truck.

A vehicle LED lighting outage detection circuit is disclosed for detecting a fault in the LED light and automatically increasing the power drawn from the light power supply in response to the fault. A complementary detection circuit is also disclosed for detecting the increased power draw and signaling a fault to an operator. The increased power draw can be selected to be in the form of a pulse that settles to a lower power draw state after a time to avoid excessive and wasteful power draw. The system can be mounted in a vehicle and, more particularly, to a semi-tractor truck.

A Short Circuit Detection module capable of detecting a fail related with the Short circuit condition in one or more LEDs contained in a series connection string comply with the failure mode (One out-All out) and can send a single failure signal to a body control module (BCM). The Short Circuit Detection module also includes a lamp driver circuit adapted to detect a change in LED current or voltage that is indicative of a LED light source failure and thereafter output the failure signal to the BCM.

The present invention relates to a measurement arrangement for detecting aging processes in individual light-emitting diodes which makes it possible to identify, and subsequently to compensate, a loss of brightness in light-emitting diodes. In this context, a relative measurement of brightness intensity is taken. The present invention further relates to a correspondingly set-up method for detecting aging processes in individual light-emitting diodes and to a computer program product comprising control commands which implement the method.

The present invention relates to a measurement arrangement for detecting aging processes in individual light-emitting diodes which makes it possible to identify, and subsequently to compensate, a loss of brightness in light-emitting diodes. In this context, a relative measurement of brightness intensity is taken. The present invention further relates to a correspondingly set-up method for detecting aging processes in individual light-emitting diodes and to a computer program product comprising control commands which implement the method.

To test a first LED, a second LED, and a third LED in a light-emitting unit, a method is disclosed herein comprising the following steps: setting the first and second LEDs in respective driven states to generate associated light; providing the third LED to receive the light associated with the first and second LEDs, thereby generating a first photocurrent and a second photocurrent; providing the first LED to receive the light associated with the second LED, thereby generating a third photocurrent; and calculating a decay factor of each of the LEDs based on the first, second, and third photocurrents.