Abstract: A lamp driving circuit has an AC/DC converter receives a dimmer voltage from a TRIAC dimmer with an on/off switch to turn on or off a lamp module having a number of LED lamp groups. The driving circuit also has an energy storage circuit and an MCU to control the switching of each of the lamp groups. The energy storage circuit provides a prolonged supply voltage to the MCU for a period of time after the dimmer is turned off so that the MCU can sense the off-time of the dimmer and count the number of consecutive times the dimmer is turned off and on during a preset time in order to control the color temperature of the lamp module. The MCU is programmed to store information regarding the color temperature the user has selected between a number of color temperatures such as 3000K, 4000K and 5000K.

Abstract: A lamp driving circuit has an AC/DC converter receives a dimmer voltage from a TRIAC dimmer with an on/off switch to turn on or off a lamp module having a number of LED lamp groups. The driving circuit also has an energy storage circuit and an MCU to control the switching of each of the lamp groups. The energy storage circuit provides a prolonged supply voltage to the MCU for a period of time after the dimmer is turned off so that the MCU can sense the off-time of the dimmer and count the number of consecutive times the dimmer is turned off and on during a preset time in order to control the color temperature of the lamp module. The MCU is programmed to store information regarding the color temperature the user has selected between a number of color temperatures such as 3000K, 4000K and 5000K.

Abstract: A dual-output driver uses two constant-current driver circuits to provide two modulated-current signals to two LED modules arranged to output lights of different color temperatures. Each of the constant-current drivers receives a dc voltage from a dc power source and a pulse-width modulation (PWM) signal. The PWM signals, PWM1 and PWM2, are provided by a voltage-to-PWM converter, which uses a single-chip microcomputer or the like programmed to sample the output voltage of a variable voltage source to generate the PWM signals. The variable voltage source can be a single 0-10V dimmer or two 0-10V dimmers. One LED module is arranged to provide output light of 3000 K and one is arranged to provide output light 6500 K. The mixed light from the two LED modules has color temperatures between 3000 K and 6500 K depending on the ratio of PWM1:PWM2.