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.

An apparatus for powering a light-emitting diode (LED) is provided including: a circuit board having an input portion, a power portion, a protection portion, and an output portion; the input portion of the circuit board including an alternating current line and a neutral current line, where the alternating current received across the alternating current line and neutral line supply two distinct, alternative paths, where each of the two distinct alternative paths include a combination of capacitors, inductors, and rectifiers to mitigate signal noise; the power portion of the circuit configured to receive power from the input portion of the circuit along the two distinct, alternative paths, to regulate the current received from the two distinct, alternative paths, and to provide power to an LED driver; and the protection portion of the circuit may be configured to mitigate voltage surges and to regulate the voltage supplied to the LED driver.

Systems and methods are provided to transmit a data encoded power signal to addressable devices. A data signal includes address and command data that varies between logical states. A controller provides a low loss rectified power signal. The controller further provides data within the power signal by forming a positive polarity rectified power waveform corresponding to data in a first state and a negative polarity rectified waveform signal corresponding to data in a second state using substantially loss-less circuitry.

A power converter for an LED lighting device includes a primary side circuit, a secondary side circuit, a detecting circuit, a load-dependent circuit, and a feedback circuit. The feedback circuit generates a feedback signal according to a detected signal which the detecting circuit generates according to a second node of the secondary side circuit. The primary side circuit adjusts a duty cycle according to the feedback signal. The secondary side circuit outputs a first output voltage at a first node of the secondary side circuit and outputs a second output voltage at a third node of the secondary side circuit, according to the duty cycle of the primary side circuit. The load-dependent circuit receives the second output voltage and controls an electrical strength between the first node and the second node of the secondary side circuit according to the first output voltage.

A circuit protection apparatus (100) is used to protect an LED drive circuit (200), and the circuit protection apparatus (100) includes a first switch unit (1) and a snubber circuit (3). The first switch unit (1) provides an electrical connection between an input terminal (100A) and the LED drive circuit (200) according to the normality of an input current (Iin) flowing through the input terminal (100A). The snubber circuit (3) provides a first delay time period (Td1) according to an input power (Vin). The snubber circuit (3) provides a start signal (Ss) to the LED drive circuit (200) according to the end of the first delay time period (Td1), and controls a first ground point (G1) of the snubber circuit (3) to be coupled to a second ground point (G2) of the LED drive circuit (200).

A driving circuit and a method for operating the driving circuit is provided for a lamp, the lamp includes a lighting unit, and a first and a second pair of connection pins for coupling the driving circuit to a power supply unit. The driving circuit includes a pre-heating detection circuit and a protection circuit. The pre-heating detection circuit is coupled to the first pair of connection pins and configured to detect a voltage between the first pair of connection pins and output a reference voltage. The protection circuit includes a switching circuit connected in series with the lighting unit, the protection circuit is configured to compare the reference voltage with an input voltage of the lamp and turn on the switching circuit to light the lighting unit when the input voltage of the lamp is greater than the reference voltage.

A driving system for driving light-emitting modules includes driving current generation modules connected respectively to the light-emitting modules, and a brightness modulation module connected to the current generation modules and the light-emitting modules. Each driving current generation module is configured to receive signals from the brightness modulation module to control a driving current that flows through the light-emitting module it is connected to. The brightness modulation module is configured to generate the signals based on voltages provided at terminals of the light-emitting modules that are connected to the driving current generation modules.

A dimmable ballast circuit for a compact fluorescent lamp controls the intensity of a lamp tube in response to a phase-control voltage received from a dimmer switch. The ballast circuit comprises a phase-control-to-DC converter circuit that receives the phase-control voltage, which is characterized by a duty cycle defining a target intensity of the lamp tube, and generates a DC voltage representative of the duty cycle of the phase-control voltage. Changes in the duty cycle of the phase-control voltage that are below a threshold amount are filtered out by the converter circuit, while intentional changes in the duty cycle of the phase-control voltage are reflected in changes in the target intensity level and thereby the intensity level of the lamp tube.

An encapsulated LED switch that incorporates a MOSFET power drivers, high current transistors, or other suitable power drivers in a PCB that attaches to the LED switch such that a low power LED switch controls the output of a high-power driver. The selected power driver PCB can be adapted to different load requirements by making simple changes. The PCB's can be interchanged to provide for a predetermined output power required for a particular application. In addition, the wire gauge size of the wires attached to the MOSFET power driver PCB can also be varied to match intended load requirements. For applications in which the LED switch is used in hostile environments, such as marine applications, the LED switch and its associated power driver PCB are encapsulated to protect the circuitry from environmental factors such as high humidity, salt water, etc.

Described herein are systems and methods for generating short load current pulses using an H-bridge. In various embodiments, this is accomplished by controlling, in a shunting mode, a low-side switch of the H-bridge to drive a first average current and controlling, in a non-shunting mode, a high-side switch of the H-bridge to drive a second average current such that the first and second average currents are substantially the same and reduce a current pulse width of the load current.