Patent ID: 11893868
Assignee: VAXCEL INTERNATIONAL CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G  F  H  Y | IPC F  G  H

Claim 51:
52. An LED lighting device configured with a tunable diffused light color temperature, comprising:
a light-emitting unit comprising a plurality of LEDs divided into at least two LED loads including at least a first LED load with N number LEDs emitting light with a first color temperature and at least a second LED load with M number LEDs emitting light with a second color temperature, wherein the first color temperature is designed with a value in a range between 1800K and 3000K and the second color temperature is designed with a value in a range between 4000K and 6500K, wherein M and N are positive integers with a value of M being greater than or equal to a value of N;
a light diffuser covering the first LED load and the second LED load to create a diffused light with a diffused light color temperature;
a power allocation circuitry electrically connected with a power source from a power supply unit and the light-emitting unit to manage a distribution of a DC power between a first electric power delivered to the first LED load and a second electric power delivered to the second LED load to perform an illumination characterized by the diffused light with the diffused light color temperature; and
at least one external control device to output at least one external control signal for tuning and selecting diffused light color temperature performance;
wherein the power allocation circuitry comprises at least a controller and an LED driver circuitry, wherein the LED driver circuitry is further configured with a first LED driver comprising a first semiconductor switching device electrically coupled to the first LED load and a second LED driver comprising a second semiconductor switching device electrically coupled to the second LED load for controlling the first electric power and the second electric power respectively delivered to the first LED load and the second LED load;
wherein the controller is electrically coupled with the first LED driver, the second LED driver, and the at least one external control device;
wherein when the light-emitting unit is in a turned-on state, the controller further outputs a first control signal to control a first conduction rate of the first semiconductor switching device of the first LED driver and a second control signal to control a second conduction rate of the second semiconductor switching device of the second LED driver to respectively deliver the first electric power to the first LED load and the second electric power to the second LED load to generate the diffused light with the diffused light color temperature thru the light diffuser according to the at least one external control signal;
wherein for tuning the diffused light color temperature, the controller operates a power allocation algorithm to reversely and complementarily adjust the first electric power and the second electric power respectively delivered to the first LED load and the second LED load such that a sum of the first electric power and the second electric power remains unchanged;
wherein for tuning the diffused light color temperature to a lower diffused light color temperature, the controller operates to increase the first conduction rate of the first semiconductor switching device to increase the first electric power delivered to the first LED load and simultaneously operates to decrease the second conduction rate of the second semiconductor switching device to decrease the second electric power delivered to the second LED load with the same pace such that a total light intensity generated by the light-emitting unit remains unchanged while the diffused light color temperature is accordingly adjusted to the lower diffused light color temperature;
wherein for tuning the diffused light color temperature to a higher diffused light color temperature, the controller operates to decrease the first conduction rate of the first semiconductor switching device to decrease the first electric power delivered to the first LED load and simultaneously operates to increase the second conduction rate of the second semiconductor switching device to increase the second electric power delivered to the second LED load with the same pace such that the total light intensity generated by the light-emitting unit remains unchanged while the diffused light color temperature is accordingly adjusted to the higher diffused light color temperature;
wherein the controller is designed with at least one diffused light color temperature switching scheme comprising a plurality of different diffused light color temperature performances to be respectively activated by the at least one external control signal generated by the at least one external control device, wherein different paired combinations of the first conduction rate and the second conduction rate respectively for controlling the first electric power delivered to the first LED load and the second electric power delivered to the second LED load for creating different diffused light color temperatures are preprogrammed and executed by the controller for operating a pick and play process according to the at least one external control signal generated by the at least one external control device for selecting a corresponding diffused light color temperature performance in the at least one diffused light color temperature switching scheme; and
wherein the N number LEDs of the first LED load and the M number LEDs of the second LED load are respectively designed with a configuration of in series and/or in parallel connections such that when incorporated with a power level setting of the DC power, an electric current passing through each LED of the first LED load and each LED of the second LED load remains at a level such that a voltage V across each LED complies with an operating constraint of Vth<V<Vmax featuring electrical characteristics of an LED, wherein Vth is a reference value of a threshold voltage required to trigger each LED to start emitting light and Vmax is a reference value of a maximum operating voltage across each LED at which at least one LED construction in said plurality of LEDs is vulnerable to a thermal damage.