An apparatus can include: a linear drive circuit configured to control a drive current flowing through an LED load; a control circuit configured to acquire a conduction angle signal of a silicon-controlled rectifier dimmer and control the linear drive circuit; and the control circuit being configured to control the drive current to be decreased to reduce a current ripple and to maintain the silicon-controlled rectifier dimmer in a turn-on state when the conduction angle signal is less than a predetermined value.

An apparatus can include: a linear drive circuit configured to control a drive current flowing through an LED load; a control circuit configured to acquire a conduction angle signal of a silicon-controlled rectifier dimmer and control the linear drive circuit; and the control circuit being configured to control the drive current to be decreased to reduce a current ripple and to maintain the silicon-controlled rectifier dimmer in a turn-on state when the conduction angle signal is less than a predetermined value.

A method of operating an LED lamp coupled with a dimmer switch and includes receiving an input signal from the dimmer switch corresponding to a setting of the dimmer switch within its dimmable range, detecting a change of the setting within the upper portion of the dimmable range, which includes 80% to 100% of a maximum setting of the dimmer switch, and, responsive to detecting the change, adjusting drive current to at least one of a first or a LED light source to change a composite CCT produced by them within a first CCT range including about 3000 Kelvin to about 5000 Kelvin while substantially maintaining a composite brightness produced by the first and second LED light sources.

A method of operating an LED lamp coupled with a dimmer switch and includes receiving an input signal from the dimmer switch corresponding to a setting of the dimmer switch within its dimmable range, detecting a change of the setting within the upper portion of the dimmable range, which includes 80% to 100% of a maximum setting of the dimmer switch, and, responsive to detecting the change, adjusting drive current to at least one of a first or a LED light source to change a composite CCT produced by them within a first CCT range including about 3000 Kelvin to about 5000 Kelvin while substantially maintaining a composite brightness produced by the first and second LED light sources.

Multiple current sources are coupled in series to corresponding light-emitting elements. Switching converter supplies driving voltage to the multiple light-emitting elements and current sources. Pulse modulator generates pulse signal that transits to on level when the smallest from among voltages across both ends of the multiple current sources falls to bottom limit voltage, and subsequently transits to off level. Frequency stabilization circuit controls pulse modulator such that the frequency of pulse signal approaches its target. Dummy load circuit is configured to lower driving voltage in the enable state, to be set to the enable state when switching transistor continues to be off for a predetermined time, and to be set to the disable state in response to the next turn-on of the switching transistor.

Multiple current sources are coupled in series to corresponding light-emitting elements. Switching converter supplies driving voltage to the multiple light-emitting elements and current sources. Pulse modulator generates pulse signal that transits to on level when the smallest from among voltages across both ends of the multiple current sources falls to bottom limit voltage, and subsequently transits to off level. Frequency stabilization circuit controls pulse modulator such that the frequency of pulse signal approaches its target. Dummy load circuit is configured to lower driving voltage in the enable state, to be set to the enable state when switching transistor continues to be off for a predetermined time, and to be set to the disable state in response to the next turn-on of the switching transistor.

System and method for controlling one or more light emitting diodes. For example, the system for controlling one or more light emitting diodes includes a current generator configured to generate a first current flowing through one or more light emitting diodes. The one or more light emitting diodes are configured to receive a rectified voltage generated by a rectifying bridge coupled to a TRIAC dimmer. Additionally, the system includes a bleeder configured to receive the rectified voltage, and a controller configured to receive a sensing voltage from the current generator and output a control signal to the bleeder. The sensing voltage indicates a magnitude of the first current.

System and method for controlling one or more light emitting diodes. For example, the system for controlling one or more light emitting diodes includes a current generator configured to generate a first current flowing through one or more light emitting diodes. The one or more light emitting diodes are configured to receive a rectified voltage generated by a rectifying bridge coupled to a TRIAC dimmer. Additionally, the system includes a bleeder configured to receive the rectified voltage, and a controller configured to receive a sensing voltage from the current generator and output a control signal to the bleeder. The sensing voltage indicates a magnitude of the first current.

A lamp is provided that includes a first housing having a recessed down lamp geometry for containing a light emitting diode (LED) light source, and a second housing for containing driver electronics including an exterior switch for selecting lighting characteristics of light being projected by the light emitting diode (LED) light source, wherein the first housing containing the light emitting diode (LED) light source and the second housing including the driver electronics are electrically connected through a reversible connector.

A lamp is provided that includes a first housing having a recessed down lamp geometry for containing a light emitting diode (LED) light source, and a second housing for containing driver electronics including an exterior switch for selecting lighting characteristics of light being projected by the light emitting diode (LED) light source, wherein the first housing containing the light emitting diode (LED) light source and the second housing including the driver electronics are electrically connected through a reversible connector.