An LED driver that is operable with two different types of power source originally designed for a high-intensity discharge lamp. The LED driver directs current of an input power provided by the power source down a first current path if it is determined that the power source comprises a functional ignitor. The LED driver directs current of an input power provided by the power source down a second current path if it is determined that the 5 power source does not comprise a functional ignitor.

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.

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.

An LED lamp and it power source module are provided. The LED lamp includes an LED module and a power source module. The power source module includes two rectifying circuits, a filtering capacitor, a plurality of fuses, two filament-simulating circuits, and a discharge device. Each of the filament-simulating circuits is configured to allow a current to flow from one pin to the other pin via the corresponding first and second filament-simulating circuits during a pre-heat process executed by a ballast.

An emergency output circuit for starting LED lamp tubes with leakage protection comprises a PWM pulse generator provided with a PWM chip. When a control terminal detects a power outage, a high level is instantly output to the PWM chip, and the PWM pulse generator outputs complementary drive PWM rectangular waves with a controllable dead time, which are boosted and filtered into a 250V DC voltage; then, positive and negative alternating square waves are formed through a full-bridge inverter circuit, and two pairs of MOS transistors are turned on alternately through complementary PWM control to generate an AC voltage UAB on an LED lamp tube; and finally, an AC rectangular wave slowly changing into a stable 135V AC output from a 250V DC output is obtained through a correction circuit to replace existing methods to turn on the LED tube, thus effectively simplifying the circuit.

An emergency output circuit for starting LED lamp tubes with leakage protection comprises a PWM pulse generator provided with a PWM chip. When a control terminal detects a power outage, a high level is instantly output to the PWM chip, and the PWM pulse generator outputs complementary drive PWM rectangular waves with a controllable dead time, which are boosted and filtered into a 250V DC voltage; then, positive and negative alternating square waves are formed through a full-bridge inverter circuit, and two pairs of MOS transistors are turned on alternately through complementary PWM control to generate an AC voltage UAB on an LED lamp tube; and finally, an AC rectangular wave slowly changing into a stable 135V AC output from a 250V DC output is obtained through a correction circuit to replace existing methods to turn on the LED tube, thus effectively simplifying the circuit.

A light-emitting diode (LED) luminaire comprising a battery-backup portion is used to replace a luminaire operated only with alternate-current (AC) mains. The battery-backup portion comprises a rechargeable battery, a self-diagnostic circuit, and a front-end communication circuit. The self-diagnostic circuit comprises timers and is configured to provide test schedules and to auto-evaluate battery performance according to the test schedules with test results stored. The LED luminaire further comprises a remote user interface and a concentrator communication circuit configured to communicate with the front-end communication circuit configured to send the test results to the concentrator communication circuit as soon as a rechargeable battery test is performed. When the remote control signals are initiated by the remote user interface with spread-spectrum modulated signals transmitted, the front-end communication circuit can demodulate such signals and subsequently send commands to the self-diagnostic circuit to respond accordingly.

A light-emitting diode (LED) luminaire comprising a battery-backup portion is used to replace a luminaire operated only with alternate-current (AC) mains. The battery-backup portion comprises a rechargeable battery, a self-diagnostic circuit, and a front-end communication circuit. The self-diagnostic circuit comprises timers and is configured to provide test schedules and to auto-evaluate battery performance according to the test schedules with test results stored. The LED luminaire further comprises a remote user interface and a concentrator communication circuit configured to communicate with the front-end communication circuit configured to send the test results to the concentrator communication circuit as soon as a rechargeable battery test is performed. When the remote control signals are initiated by the remote user interface with spread-spectrum modulated signals transmitted, the front-end communication circuit can demodulate such signals and subsequently send commands to the self-diagnostic circuit to respond accordingly.

A light emitting load driving device includes a first constant current source structured to be serially connected to a first light emitting load group; a second constant current source structured to be serially connected to a second light emitting load group; a first load connection terminal structured to be connected to the first light emitting load group; a second load connection terminal structured to be connected to the second light emitting load group; and a control circuit structured to be supplied a first voltage applied to the first load connection terminal, a second voltage applied to the second load connection terminal, and a reference voltage applied to the control circuit, wherein the control circuit is structured to select a minimum voltage between the first voltage and the second voltage, and the control circuit is structured to equalize the minimum voltage and the reference voltage.

The present disclosure provides a light emitting element driving device. The light emitting element driving device includes a constant current circuit and a current detection unit. The constant current circuit includes: a first transistor including a first end, a second end and a control end connected to an external terminal; a current setting resistance connected to the second end of the first transistor; and a drive amplifier including a first input end connected to a first node to which the first transistor and the current setting resistance are connected, a second input end to which a current set voltage is applied, and an output end connected to the control end of the first transistor. The current detection unit generates a current detection signal based on a feedback voltage generated in the first node.