A disconnect component coupled between a lighting load and a main power line. The disconnect component includes an input coupled to the main power line and a neutral line input to the disconnect component from the 277 volt circuit and an output coupled to the lighting load. The disconnect component includes a monitor that monitors a voltage on the main power line and a coupling component that couples the main power line to the output. The coupling component is configured to decouple the main power line from the output when the monitor senses a voltage on the main power line is higher than an upper limit voltage and re-couple the main power line to the output when the monitor senses that the voltage on the main power line is below the upper limit voltage.

LED related lighting methods and apparatus are described. Various features relate to water tight light fixtures. Some of the fixtures are spotlights while other fixture are intended for in ground use. The light fixtures in at least some embodiments include power control features. In spotlight embodiments beam angle and power or light output can be controlled without opening the light assembly or compromising the water tight seals which also protect against dirt. In ground embodiments support tilt angle setting which allow a user to set the light fixture to one or more tilt angles. Beam angle can also be changed in some embodiments as well as power control. Beam angle, power control and tilt angle adjustments are supported in some embodiments but need not be supported in all embodiments with some embodiments using one or more of the described features but not all features.

A load-switch voltage control circuit includes a power control circuit for controlling a switching element that stabilizes the voltage to a load. The power control circuit determines intervals of conduction for the switching element, that connects a control impedance to the load, for stabilizing the voltage across the load.

Provided are an open-mode protection device and an electronic device having the same. An open-mode protection device according to an embodiment of the present invention is connected in parallel to each of a constant current source and a load configured with a light emitting diode (LED). The open-mode protection device comprises a first external electrode connected to one sides of the constant current source and the load; a second external electrode connected to the other sides of the constant current source and the load, and a ground; a protection unit configured to bypass, to the ground through the second external electrode, an overvoltage or an overcurrent flowing into the first external electrode; and a current suppressing unit connected in series to the protection unit and configured to sense a temperature or current of the protection unit and reduce the current of the protection unit as the temperature or current increases.

A lighting relay panel may include lower-cost features or components related to improved safety and reliability. In some cases, the relay panel includes a power supply capable of protecting the panel from high-voltage and high-current transients. A microcontroller may determine a power interruption based on a zero-cross signal received from the power supply, and may also configure latching relays during the interruption. In some implementations, the relay panel includes a relay sense circuit that is capable of receiving actuation signals from multiple relays connected to different phases of a power signal, and the microcontroller may synchronize or repeat the actuations based on a signal from the relay sense circuit. The microcontroller may generate relay addresses based on the relay positions within the relay panel. In some cases, the relay panel may include isolation circuits that are capable of providing an isolated control signal having an improved voltage range.

An airport lighting system includes one or more lighting elements, a transient protection apparatus, and one or more electrical control cabinets. The transient protection apparatus is coupled to the one or more lighting elements. One or more electrical control cabinets are coupled to the transient protection apparatus. Each of the control cabinets produces one or more of control and power signals that are effective to operate the one or more lighting elements. The transient protection apparatus is configured to provide protection for one or more of the electrical control cabinets and the one or more lighting elements from electrical surges.

An LED tube lamp includes a lamp tube; an LED light strip disposed inside the lamp tube and comprising a mounting region and a connecting region, a plurality of LED light sources mounted on the mounting region and at least two first connecting pads arranged on the connecting region; a fixing structure disposed inside the lamp tube and extending along the longitudinal direction of the lamp tube, the fixing structure comprising a first end fixedly connected to an inner circumferential surface of the lamp tube and second end fixedly connected to the LED light strip; a power supply module disposed on the fixing structure and electrically connecting to the LED light strip via the two first connecting pads, the power supply module comprising a circuit board separate from the light strip and a plurality of electronic components mounted on the circuit board; and two end caps attached to two ends of the lamp tube respectively. The power supply module comprises at least a rectifying circuit and a filtering circuit, wherein the rectifying circuit is coupled to two pins to receive an external signal, and the filtering circuit is coupled to the rectifying circuit and is configured to receive a signal from the rectifying circuit.

A lighting relay panel may include lower-cost features or components related to improved safety and reliability. In some cases, the relay panel includes a power supply capable of protecting the panel from high-voltage and high-current transients. A microcontroller may determine a power interruption based on a zero-cross signal received from the power supply, and may also configure latching relays during the interruption. In some implementations, the relay panel includes a relay sense circuit that is capable of receiving actuation signals from multiple relays connected to different phases of a power signal, and the microcontroller may synchronize or repeat the actuations based on a signal from the relay sense circuit. The microcontroller may generate relay addresses based on the relay positions within the relay panel. In some cases, the relay panel may include isolation circuits that are capable of providing an isolated control signal having an improved voltage range.

A semiconductor device includes a first overvoltage detection unit including a first comparator arranged to output a first detection signal based on a first divided voltage after dividing an output voltage of a power supply circuit by first resistors disposed externally and a second overvoltage detection unit including second resistors and a second comparator arranged to output a second detection signal based on a second divided voltage after dividing the output voltage by the second resistors.

A short protecting circuit for a LED (Light-emitting Diode) driver for powering a plurality of LED strings, having: a short comparing circuit, configured to provide a plurality of short fault indicating signals; a first logic circuit, configured to provide a short fault signal based on the plurality of short fault indicating signals to indicate a short fault condition; a timing circuit, configured to provide a short protecting enable signal; and a second logic circuit, configured to provide a plurality of short isolating signals; wherein the short isolating signals are blocked when an open fault signal is valid.