An LED tube lamp includes a lamp tube, two end caps, and an LED light strip. The two end caps are respectively at two opposite ends of the lamp tube. The LED light strip is in the lamp tube and is provided with one or more LED light sources mounted thereon. Each of the end caps includes an electrically insulating tube, two conductive pins, and two or more heat-dissipating openings. The two conductive pins are disposed on the electrically insulating tube. The two heat-dissipating openings are formed on the electrically insulating tube and are symmetric to each other with respect to a vertical central plane passing through the middle of a line connecting the two conductive pins.

A backlight unit includes a light source; and a light-source driving unit configured to drive the light source and that includes a transformer. The transformer includes a core comprising a plurality of metal powders; and a plurality of coils embedded in the core. At least one coil has a diameter different from a diameter of another coil.

A Light Emitting Diode (LED) light includes a bridge rectifier configured to be powered by an alternating current power source and to produce a rectified output. Control circuitry couples to the bridge rectifier and is configured to produce a shunt signal when the rectified output is less than a threshold voltage. A series connected Light Emitting Diode (LED) string includes a first group of LEDs and a second group of LEDs. A switch couples to a first side of the second group of LEDs and is controlled by the shunt signal to deactivate the second group of LEDs. The control circuitry may include a ratio metric series resistor string configured to sense a proportion of the rectified output and an inverter configured to generate the shunt signal based on the proportion of the rectified output.

In accordance with certain embodiments, lighting systems include one or more lightsheets each including a plurality of strings of light-emitting elements, control elements, and power conductors for supplying power to the light-emitting elements and control elements.

LED-based light source modules can incorporate color tunability and brightness control, allowing a user to select a desired color temperature and/or brightness and to change either or both dynamically. An emitter can include multiple independently addressable groups of LEDs, each emitting light of a different color. By controlling the relative operating current provided to each group, a desired color temperature can be achieved, and by controlling the absolute operating currents, the brightness of the output light can be controlled. Pulse width modulation (PWM) can be used to control the relative and absolute operating currents. Smooth, gradual transitions between brightness and/or color temperature settings in response to changes can be provided.

A low-voltage alternating current-based LED light with built-in cooling and automatic or manual dimming. As it is self-cooled with fan failure protection, the light can be safely run in conditions that are near-hostile to its operation, with little possibility of damage. The light is movable along the XY axes of a grid system and can be either fixed in position in the Z axis or can be movable up and down the Z axis. The light can be equipped with either manual dimming using a standard potentiometer, or with automatic dimming via sensors and local network connectivity. The device prevents line-voltage electric shocks as the input voltage is low-voltage AC; in embodiments, about the same voltage as a doorbell, and the input current is 3 A. The device is also self-cooled, and will shut down if its fan is not running so as to prevent thermal overloads.

A sequential driving type alternating current (AC) LED lighting apparatus including a rectifier connected to an alternating current (AC) power source and outputting a first rectified voltage as a first drive voltage to a light-emitting diode (LED) light-emitting device through full-wave rectification of an AC voltage, and an LED drive controller configured to detect a first drive voltage applied to the LED light emitting device and control sequential driving based on the detected first drive voltage. The LED drive controller is configured to set an LED drive current in each of operation sections, such that a difference between light output of the LED light-emitting device in each of the operation sections does not exceed a predetermined light output deviation.

A light string includes a plurality of lights and a plurality of non-polarity capacitor corresponding to the lights; wherein, the lights are electrically connected in series and to be powered by an AC power supply; each of the non-polarity capacitor is connected in parallel to a corresponding one of the lights. When the light string is powered on, the non-polarity capacitor is charged and absorbs the surge current which may occur. Thus, the voltage dropped on each light rises slowly and the lights are safe. The non-polarity capacitor also performs power compensation and electrical connection.

A light string includes a plurality of lights and a plurality of non-polarity capacitor corresponding to the lights; wherein, the lights are electrically connected in series and to be powered by an AC power supply; each of the non-polarity capacitor is connected in parallel to a corresponding one of the lights. When the light string is powered on, the non-polarity capacitor is charged and absorbs the surge current which may occur. Thus, the voltage dropped on each light rises slowly and the lights are safe. The non-polarity capacitor also performs power compensation and electrical connection.

An electronic torch is disclosed which includes at least one light emitting diode disposed in each one of a plurality of sections of the electronic torch. In one embodiment, each one of the plurality of sections of the electronic torch is independently selectable to activate the at least one light emitting diode disposed in each one of the plurality of sections of the electronic torch. In another embodiment, a mobile device may be connected to the electronic torch and provide instructions to the torch via a wired or wireless connection.