A load regulation device, such as an LED driver, may be configured to control the intensity of a light source based on an analog control signal and a preconfigured dimming curve. The LED driver may sense a magnitude of the analog control signal and determine a new low-end and/or high-end control signal magnitude that falls outside of the input signal range of the dimming curve. The LED driver may rescale the preconfigured dimming curve according to new low-end and/or high-end control signal magnitudes and dim the light source based on the rescaled dimming curve. Multiple LED drivers controlled by the same analog control signal may communicate with each other regarding the magnitude of the analog control signal sensed by each LED driver, and match their target intensity levels despite sensing different analog control signal. A controller may be provided to coordinate the operation of the multiple LED drivers.

A load regulation device, such as an LED driver, may be configured to control the intensity of a light source based on an analog control signal and a preconfigured dimming curve. The LED driver may sense a magnitude of the analog control signal and determine a new low-end and/or high-end control signal magnitude that falls outside of the input signal range of the dimming curve. The LED driver may rescale the preconfigured dimming curve according to new low-end and/or high-end control signal magnitudes and dim the light source based on the rescaled dimming curve. Multiple LED drivers controlled by the same analog control signal may communicate with each other regarding the magnitude of the analog control signal sensed by each LED driver, and match their target intensity levels despite sensing different analog control signal. A controller may be provided to coordinate the operation of the multiple LED drivers.

The present disclosure provides a power factor improvement circuit with a DC/DC converter including an arithmetic circuit. A first voltage having a full-wave rectified waveform is received by an input voltage detection terminal of the power factor improvement circuit. A second voltage is generated by amplifying an error between a first detection voltage and a reference voltage according to an output voltage of the DC/DC converter. A third voltage is generated by multiplying the first voltage by the second voltage. The arithmetic circuit adds an offset voltage to a third voltage to generate a fourth voltage. A comparator is configured to compare a second detection voltage with the fourth voltage. A drive circuit is configured to turn on/off drive of the switching transistor according to an output of the comparator. When the second detection voltage is higher than the fourth voltage, the switching transistor is turned off.

The present disclosure provides a power factor improvement circuit with a DC/DC converter including an arithmetic circuit. A first voltage having a full-wave rectified waveform is received by an input voltage detection terminal of the power factor improvement circuit. A second voltage is generated by amplifying an error between a first detection voltage and a reference voltage according to an output voltage of the DC/DC converter. A third voltage is generated by multiplying the first voltage by the second voltage. The arithmetic circuit adds an offset voltage to a third voltage to generate a fourth voltage. A comparator is configured to compare a second detection voltage with the fourth voltage. A drive circuit is configured to turn on/off drive of the switching transistor according to an output of the comparator. When the second detection voltage is higher than the fourth voltage, the switching transistor is turned off.

A load control device for controlling the power delivered from an AC power source to an electrical load includes a thyristor, a gate coupling circuit for conducting a gate current through a gate of the thyristor, and a control circuit for controlling the gate coupling circuit to conduct the gate current through a first current path to render the thyristor conductive at a firing time during a half cycle. The gate coupling circuit is able to conduct the gate current through the first current path again after the firing time, but the gate current is not able to be conducted through the gate from a transition time before the end of the half-cycle until approximately the end of the half-cycle. The load current is able to be conducted through a second current path to the electrical load after the transition time until approximately the end of the half-cycle.

A load control device for controlling the power delivered from an AC power source to an electrical load includes a thyristor, a gate coupling circuit for conducting a gate current through a gate of the thyristor, and a control circuit for controlling the gate coupling circuit to conduct the gate current through a first current path to render the thyristor conductive at a firing time during a half cycle. The gate coupling circuit is able to conduct the gate current through the first current path again after the firing time, but the gate current is not able to be conducted through the gate from a transition time before the end of the half-cycle until approximately the end of the half-cycle. The load current is able to be conducted through a second current path to the electrical load after the transition time until approximately the end of the half-cycle.

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.

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.

Disclosed is a driving circuit for a Light Emitting Diode (LED) lamp, the LED lamp containing the driving circuit and a method for operating the driving circuit. The driving circuit includes: three alternating voltage input terminals, including two alternating voltage input terminals for receiving an alternating voltage and one common terminal, the two alternating voltage input terminals are controlled so that at least one alternating voltage input terminal receives the alternating voltage from a power supply; a constant current control circuit receiving the alternating voltage through at least one alternating voltage input terminal and outputting a constant direct current to an LED load, the constant current control circuit includes a constant current control chip having a maximum on-time pin; and a three-stage dimming detection control circuit including a variable control resistor for three-stage dimming control, and is controlled by the alternating voltage received by at least one alternating voltage input terminal so that the variable control resistor is connected to the maximum on-time pin with different resistance values, and the constant current control chip outputs three different current levels according to a resistance value of the connected variable control resistor.

Disclosed is a driving circuit for a Light Emitting Diode (LED) lamp, the LED lamp containing the driving circuit and a method for operating the driving circuit. The driving circuit includes: three alternating voltage input terminals, including two alternating voltage input terminals for receiving an alternating voltage and one common terminal, the two alternating voltage input terminals are controlled so that at least one alternating voltage input terminal receives the alternating voltage from a power supply; a constant current control circuit receiving the alternating voltage through at least one alternating voltage input terminal and outputting a constant direct current to an LED load, the constant current control circuit includes a constant current control chip having a maximum on-time pin; and a three-stage dimming detection control circuit including a variable control resistor for three-stage dimming control, and is controlled by the alternating voltage received by at least one alternating voltage input terminal so that the variable control resistor is connected to the maximum on-time pin with different resistance values, and the constant current control chip outputs three different current levels according to a resistance value of the connected variable control resistor.