Method of tuning light color temperature for LED lighting device and application thereof

An LED lighting device, comprising:

• a first light-emitting unit, configured with at least two LED circuits including at least a first LED circuit comprising a first LED load emitting a first white light with a first color temperature CT1 and at least a second LED circuit comprising a second LED load emitting a second white light with a second color temperature CT2 to form the first light-emitting unit for generating a first illumination, wherein the first illumination is designed to brighten up a living space surrounding the LED lighting device, wherein the second color temperature is higher than the first color temperature, namely CT2>CT1;
• a first light diffuser, covering the first LED load and the second LED load capable of blending the first white light and the second white light to generate the first illumination with a mingled light color temperature CTapp;
• a second light-emitting unit, configured with at least a third LED circuit comprising a third LED load emitting a third white light with a third color temperature CT3 for generating a second illumination;
• a second light diffuser, covering and surrounding the third LED load to guide and diffuse the third white light generated by the third LED load along a mounting surface behind the LED lighting device to generate the second illumination with a surface-wash light;
• wherein the second illumination generated by the second light-emitting unit is for distributing and diffusing an accent light along a ceiling surface or along a wall surface behind the LED lighting device;
• a switching circuitry, electrically coupled with a power source of a power supply unit and the two light-emitting units to output at least one DC power with a constant current for energizing the first light-emitting unit and the second light-emitting unit;
• a first power allocation circuitry, installed with the switching circuitry and the first light-emitting unit to allocate a first electric power X delivered to the first LED circuit and a second electric power Y delivered to the second LED circuit to operate a selection of the mingled light color temperature of the first illumination of the first light-emitting unit thru the first light diffuser when the first light-emitting unit is energized;
• a second power allocation circuitry, installed with the switching circuitry and the second light-emitting unit to deliver at least a third electric power to the third LED circuit to emit the third white light with the third color temperature for controlling at least an on/off performance of the second illumination of the second light-emitting unit;
• a power allocation algorithm, working in conjunction with the first power allocation circuitry to operate a power allocation scheme comprising a plurality of power loading options configured with different paired combinations of the first electric power X delivered to the first LED circuit and a second electric power Y delivered to the second LED circuit by implementing a reverse yet complementary power adjustment process between the first electric power X and the second electric power Y such that a total light intensity generated by the first LED load and the second LED load remains unchanged while the mingled light color temperature of the first illumination of the first light-emitting unit thru the first light diffuser is being adjusted;
• wherein the first LED load, the second LED load and the third LED load are phosphor based white LEDs produced by coating different phosphor compounds on surfaces of LEDs to respectively generate the white light LEDs with the first color temperature, the second color temperature and the third color temperature;
• wherein the units of the mingled light color temperature generated by the first light-emitting unit, the first color temperature generated by the first LED load, the second color temperature generated by the second LED load and the third color temperature generated by the third LED load are Kelvin (K), and the units of the first electric power X and the second electric power Y are Watt (W);
• wherein the first color temperature is designed in a color temperature range between 2000K and 3000K, wherein the second color temperature is designed in a color temperature range between 4000K and 6500K, wherein the third color temperature is designed in a color temperature range between 2000K and 6500K;
• a first external control device, designed with a capacity to operate a pick and play process to select a corresponding power loading option in the power allocation scheme for performing a corresponding mingled light color temperature when the first light-emitting unit is energized;
• a second external control device, configured to activate the first power allocation circuitry to energize the first light-emitting unit and to activate the second power allocation circuitry to energize the second light-emitting unit to perform at least one of the first illumination and/or the second illumination;
• and
• a controller, electrically coupled with the first power allocation circuitry, the second power allocation circuitry and at least the second external control device to activate at least one of the first power allocation circuitry and/or the second power allocation circuitry.