An AC-DC power supply receives input AC power and outputs DC power. The converter includes a high power factor bridge rectifier, a barrier circuit with resistor(s) and capacitor(s), and a step-down switching DC-DC converter to step-down a first DC voltage to a second, lower, DC voltage for output. Additionally, fault-protection is provided by redundancy in diodes on diode legs of a bridge rectifier and capacitor(s) of a filter circuit thereof, and a fault-protection circuit to sense current from a step-down switching DC-DC converter, a first voltage from the step-down switching DC-DC converter, and/or a second voltage at an output of the step-down switching DC-DC converter, and open the circuit on a fault.

An AC-DC power supply receives input AC power and outputs DC power. The converter includes a high power factor bridge rectifier, a barrier circuit with resistor(s) and capacitor(s), and a step-down switching DC-DC converter to step-down a first DC voltage to a second, lower, DC voltage for output. Additionally, fault-protection is provided by redundancy in diodes on diode legs of a bridge rectifier and capacitor(s) of a filter circuit thereof, and a fault-protection circuit to sense current from a step-down switching DC-DC converter, a first voltage from the step-down switching DC-DC converter, and/or a second voltage at an output of the step-down switching DC-DC converter, and open the circuit on a fault.

Methods and apparatus for implementing a control apparatus for a light fixture for externally controlling the current to the LED light emitter of a landscape LED light fixture. In an exemplary embodiment a control apparatus for controlling current to an LED light source in a landscape lighting device includes an LED driver, a user control with a control setting indicator, and a driver housing including setting indicators.

An LED tube lamp comprises: a glass lamp tube; a light diffusion layer disposed on a surface of the glass lamp tube; an LED light strip, which comprises a fixing portion and an extending portion disposed in the glass lamp tube; a plurality of LED light sources mounted on the fixing portion of the LED light strip; a fixing structure disposed between the fixing portion and the inner circumferential surface the glass lamp tube; a power supply module disposed on the fixing structure and electrically connecting to the LED light strip and two end caps attached to two ends of the glass lamp tube respectively. The fixing structure comprises a first end fixedly connected to the inner circumferential surface of the glass lamp tube and a second end fixedly connected to the fixing portion of the LED light strip and not connected to the extending portion of the LED light strip.

A 2-Wire LED dimming system and method re-purposes existing 120V AC architecture and hardware to carry low voltage PWM gradient DC power to the LED lamps provides a consistent gradation over a 0-100% dimming range. An LED Driver is electrically connected to an AC power source and connect to at least one LED lamp. The AC power source is electrically connected to an AC to DC converter where the AC power is converted to filtered and regulated DC power for the control unit and the power switch. The power switch is electrically connected to the AC to DC converter DC power output. The control unit is electrically connected to the power switch which is turned ON or OFF according to the pulse width modulation PWM signal from the control unit in order to connect or disconnect the DC power from the AC to DC converter.

A 2-Wire LED dimming system and method re-purposes existing 120V AC architecture and hardware to carry low voltage PWM gradient DC power to the LED lamps provides a consistent gradation over a 0-100% dimming range. An LED Driver is electrically connected to an AC power source and connect to at least one LED lamp. The AC power source is electrically connected to an AC to DC converter where the AC power is converted to filtered and regulated DC power for the control unit and the power switch. The power switch is electrically connected to the AC to DC converter DC power output. The control unit is electrically connected to the power switch which is turned ON or OFF according to the pulse width modulation PWM signal from the control unit in order to connect or disconnect the DC power from the AC to DC converter.

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 MOSFET circuit clamps a MOSFET gate voltage (either directly or via a gate control circuit) when the source voltage exceeds a threshold level, for example in response to a voltage surge event between the source and drain. In particular, the gate is held at a voltage relative to the source, to turn off the first MOSFET during such a surge event, but not during normal operation. This provides automatic protection against unwanted increases in the input voltage, especially when the MOSFET was in its on state during the switching. A threshold circuit is connected between a gate (or gate control node) and a reference voltage. When the voltage at the source exceeds a voltage threshold level, it conduct a unidirectional circuit component (D18) between the source and gate (or gate control node), and the threshold circuit.

System and method for regulating one or more currents. The system includes a system controller, an inductor, a first resistor, a switch and a first diode. The system controller includes a first controller terminal and a ground terminal, the system controller being configured to output a drive signal at the first controller terminal. The inductor includes a first inductor terminal and a second inductor terminal, the first inductor terminal being coupled to the ground terminal, the second inductor terminal being coupled to one or more light emitting diodes. The first resistor includes a first resistor terminal and a second resistor terminal, the first resistor terminal being coupled to the ground terminal. The switch is configured to receive the drive signal and coupled to the second resistor terminal. The first diode includes a first diode terminal and a second diode terminal and coupled to the first resistor.

System and method for regulating one or more currents. The system includes a system controller, an inductor, a first resistor, a switch and a first diode. The system controller includes a first controller terminal and a ground terminal, the system controller being configured to output a drive signal at the first controller terminal. The inductor includes a first inductor terminal and a second inductor terminal, the first inductor terminal being coupled to the ground terminal, the second inductor terminal being coupled to one or more light emitting diodes. The first resistor includes a first resistor terminal and a second resistor terminal, the first resistor terminal being coupled to the ground terminal. The switch is configured to receive the drive signal and coupled to the second resistor terminal. The first diode includes a first diode terminal and a second diode terminal and coupled to the first resistor.