A protection circuit and an illumination driving circuit are described herein. The protection circuit comprises a detection circuit, detecting a current flowing through a first switch to obtain a current detection signal and determining whether there is leakage at an input terminal according to the current detection signal; a control circuit, controlling the first switch to switch on intermittently, detecting the current flowing through the first switch by the detection circuit during a switch-on period of the first switch, and keeping the load at a disconnection state if the detection circuit determines there is leakage; and the first switch, connected to the input terminal, and a control terminal of the first switch being connected to the control circuit, and the first switch being controlled by the control circuit to be switched on intermittently. The present invention has the protection function and enhances safety during load removing and installation processes.

A light-emitting diode (LED) tube lamp comprising a tube, end caps with contact pins and located on both ends of the tube, a first rectifying circuit and a second rectifying circuit and a filtering circuit that are coupled with the contact pins on the two end caps respectively, and a switch circuitry that is located between the rectifying circuits and the filtering circuit characterized in that the switch circuitry is capable of detecting whether the LED tube lamp is correctly installed on a lamp socket so as to reduce the risk of electric shock.

Apparatus, systems, and methods for controlling light output in a lighting system based on defined light profiles are provided. In one example implementation, a light fixture can include a first light emitting diode (LED) array having one or more LED light sources and a second LED array having one or more LED light sources. The light fixture can include a power circuit configured to provide power to the first LED array and the second LED array according to a power distribution among the first LED array and the second LED array. The light fixture can include one or more control devices configured to control the power circuit to adjust the power distribution among the first LED array and the second LED array based at least in part on a signal indicative of a real time clock and a defined light profile associated with a user identified to be present in a space illuminated by the light fixture.

A lighting system is disclosed that includes elongated LED light fixture with one or more master circuit boards configured to power light emitting diodes. The elongated LED light fixtures include modular light boards with arrays of light emitting diodes that interchangeably couple to the matched connectors on the master circuit board. The system further includes elongated LED light fixtures with telescoping end features, fenestrated diffuser optics at ends of the elongated LED fight fixtures and/or pivoting corner features that join sections of the elongated LED light fixtures.

A control circuit for a step dimming circuit includes a first line power lead, a second line power lead, a first relay pole, powered by the first line power lead, for switching power from the first and second line power leads to a power supply line, a second relay pole powered by the first line power lead and connected to a first control lead, a third relay pole powered by the second line power lead and connected to a second control lead and connected to the second relay pole, where the second and third relay poles are configured to connect the first and second control leads together when only one of the second and third relay poles are powered, and where the second and third relay poles are configured to disconnect the first and second control leads when both of the second and third relay poles are powered.

Techniques for determining a position of a mobile device using visible light communication signals are provided. An example device includes memory and a processor configured to in response to a determination that at least one first image of a plurality of images stored in the memory is of a modulated light signal transmitted by a light source and comprising coded information, determine a spatial location of a reference point of the light source based on the coded information, in response to a determination that at least one second image of the plurality of images is of an unmodulated light signal emanating from the light source, determine an image location of the reference point of the light source in the at least one second image, and determine a position of the mobile wireless communication device based on the image location of the reference point and the spatial location of the reference point.

A dual-output power adapter for a lighted artificial tree having a plurality of tree portions with light strings having lighting elements. The dual-output power adapter includes a power cord including a first power conductor and a second power conductor, the power cord configured to transmit an input electrical power; a housing configured to receive the first power conductor and a second power conductor; power-converting circuitry in electrical connection with the first power conductor and the second power conductor, the power-converting circuitry configured to convert the input electrical power to a first output electrical power; a first pair of conductors for transmitting the first output electrical power; and a second pair of conductors for transmitting a second output electrical power.

A light emitting diode lighting assembly that receives an electrical excitation signal that is varied from a dimming device. Driving circuitry receives the varying input and has first and second paths that each have a plurality of light emitting diodes. Each plurality of light emitting diodes has a threshold voltage with the threshold voltage of the first plurality of diodes being less than the threshold voltage of the second plurality of lighting emitting diodes. The current within the first path is controlled by a current limiting device that is controlled by a resistor that receives input from the second path to gradually turn off the first plurality of light emitting diodes as the second plurality of lighting emitting diodes increase in intensity. A shunt voltage regulator within the circuit having a threshold voltage that is above threshold voltages of components in the assembly to minimize voltage increases in the assembly.

The embodiments disclosed herein describe a set of fault detection circuits for LED circuits in an LED channel. A first fault detection circuit is configured to detect a short fault across one or more LEDs. A second fault detection circuit is configured to detect an open fault across an LED. A third fault detection circuit is configured to detect a short across an LED channel transistor. A fourth fault detection circuit is configured to detect an LED channel sense resistor open fault. A fifth fault detection circuit is configured to detect if the LED channel is being intentionally unused. These fault detect circuits can be implemented in a fault detection integrated circuit coupled to the LED channel.

An LED tube lamp is disclosed. The LED tube lamp includes a lamp tube, a first external connection terminal and a second external connection terminal coupled to the lamp tube and for receiving an external driving signal, a rectifying circuit coupled to the first external connection terminal and the second external connection terminal and configured to rectify the external driving signal to produce a rectified signal, a filtering circuit coupled to the rectifying circuit and configured to filter the rectified signal to produce a filtered signal, an LED module coupled to the filtering circuit and configured to receive the filtered signal for emitting light; and a conduction-delaying circuit coupled to the rectifying circuit and comprising a conduction-delaying device, wherein the conduction-delaying circuit is configured such that when the external driving signal is initially input to the LED tube lamp, the conduction-delaying device is in an open-circuit state, and then the conduction-delaying device will enter a conducting state when voltage across the conduction-delaying device exceeds the conduction-delaying device's trigger voltage value, wherein the conducting state of the conduction-delaying device causes the LED module to conduct current for emitting light.