Abstract: An LED (Light-Emitting Diode) output power adjusting device includes an analog/digital conversion and detection circuit, a computation and control unit, a digital/analog conversion control circuit, and a power supply circuit. The analog/digital conversion and detection circuit is connected to an LED based load to detect a forward voltage thereof and converts the forward voltage into an output of digital signal. The computation and control unit perform evaluation and computation on the digital signal of the forward voltage to obtain a digital current control signal indicating a corresponding current. The digital/analog conversion control circuit converts the digital current control signal into an analog current control signal, which is then fed to a constant current drive circuit of the LED based load to adjust an output power of the LED based load to approximate a constant power condition.

Abstract: A protection circuit is provided for a T8 LED lighting tube, including at least two power transmission connectors and at least two rectification circuits. The power transmission connectors are respectively mounted to opposite ends of the T8 LED tube and each has at least two contacts that are respectively engageable with tube retention connectors formed on opposite ends of a T8 fluorescent light fixture to receive an external AC power. Each rectification circuit is composed of at least one rectifier semiconductor and the two rectification circuits are respectively connected to the contacts of the two power transmission connectors.

Abstract: A protection circuit is provided for a T8 LED lighting tube, including at least two power transmission connectors and at least two rectification circuits. The power transmission connectors are respectively mounted to opposite ends of the T8 LED tube and each has at least two contacts that are respectively engageable with tube retention connectors formed on opposite ends of a T8 fluorescent light fixture to receive an external AC power. Each rectification circuit is composed of at least one rectifier semiconductor and the two rectification circuits are respectively connected to the contacts of the two power transmission connectors.

Abstract: An LED (Light-Emitting Diode) output power adjusting device includes an analog/digital conversion and detection circuit, a computation and control unit, a digital/analog conversion control circuit, and a power supply circuit. The analog/digital conversion and detection circuit is connected to an LED based load to detect a forward voltage thereof and converts the forward voltage into an output of digital signal. The computation and control unit perform evaluation and computation on the digital signal of the forward voltage to obtain a digital current control signal indicating a corresponding current. The digital/analog conversion control circuit converts the digital current control signal into an analog current control signal, which is then fed to a constant current drive circuit of the LED based load to adjust an output power of the LED based load to approximate a constant power condition.