A lighting system includes a light engine including a correlated color temperature (CCT) terminal configured to transmit a first power signal having a first variance and to receive a CCT signal, the light engine being configured to emit light according to the CCT signal, and a CCT clamp coupled to the CCT terminal, and configured to receive the first power signal and to generate the CCT signal having a second variance, the first variance of the first power signal being greater than the second variance of the CCT signal.

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.

The present techniques generally concern methods and systems for monitoring and managing reactive power from horticultural lighting sources in an electrical grid. The techniques provided herein include determining or predicting distortive effects produced by the horticultural lighting sources, evaluating a power factor of the horticultural light sources, and based on a target power factor, adjusting the power factor of the horticultural light sources. The techniques described herein allow for an optimization of the power factor of the horticultural lighting sources in order to reduce, mitigate or eliminate the negative effects generally associated with the operation of horticultural light sources on the electrical grid.

The present techniques generally concern methods and systems for monitoring and managing reactive power from horticultural lighting sources in an electrical grid. The techniques provided herein include determining or predicting distortive effects produced by the horticultural lighting sources, evaluating a power factor of the horticultural light sources, and based on a target power factor, adjusting the power factor of the horticultural light sources. The techniques described herein allow for an optimization of the power factor of the horticultural lighting sources in order to reduce, mitigate or eliminate the negative effects generally associated with the operation of horticultural light sources on the electrical grid.

System and method for controlling a bleeder current to increase a power factor of an LED lighting system without any TRIAC dimmer. For example, the system for controlling a bleeder current to increase a power factor of an LED lighting system without any TRIAC dimmer includes: a first current controller configured to receive a rectified voltage generated by a rectifier that directly receives an AC input voltage without through any TRIAC dimmer; and a second current controller configured to: control a light emitting diode current flowing through one or more light emitting diodes that receive the rectified voltage not clipped by any TRIAC dimmer; and generate a sensing voltage based at least in part upon the light emitting diode current, the sensing voltage representing the light emitting diode current in magnitude.

System and method for controlling a bleeder current to increase a power factor of an LED lighting system without any TRIAC dimmer. For example, the system for controlling a bleeder current to increase a power factor of an LED lighting system without any TRIAC dimmer includes: a first current controller configured to receive a rectified voltage generated by a rectifier that directly receives an AC input voltage without through any TRIAC dimmer; and a second current controller configured to: control a light emitting diode current flowing through one or more light emitting diodes that receive the rectified voltage not clipped by any TRIAC dimmer; and generate a sensing voltage based at least in part upon the light emitting diode current, the sensing voltage representing the light emitting diode current in magnitude.

A high-compatibility lighting dimmer is provided, which includes an impedance inspection avoidance module, a dimming operation module, an alternating-voltage input module and a dimming control module. The impedance inspection avoidance circuit is connected to a load via an output end. The dimming operation module is connected to the impedance inspection avoidance module and includes a control unit. The alternating-voltage input module is connected to the dimming operation module and converts an input alternating voltage into a pulsating direct voltage to power the load and the dimming operation module. The dimming control module is connected to the control unit and transmits a dimming signal to the control unit. When the load is driven, the control unit starts timing and switches the impedance inspection avoidance module after a predetermined time period, whereby the dimming operation module directly powers the load and performs dimming for the load according to the dimming signal.

An LED driver for an LED lamp, which also comprises an LED load. The LED driver is adapted to connect to an input source at a first and second terminal. The LED driver comprises a switching arrangement configured to enable a controller to control at least a magnitude and phase of the voltage between the first and second terminals. The phase of the voltage between the first and second terminals may be defined to control an amount of power that flows from the input source to power the LED lamp.

An LED driver for an LED lamp, which also comprises an LED load. The LED driver is adapted to connect to an input source at a first and second terminal. The LED driver comprises a switching arrangement configured to enable a controller to control at least a magnitude and phase of the voltage between the first and second terminals. The phase of the voltage between the first and second terminals may be defined to control an amount of power that flows from the input source to power the LED lamp.