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 96:
97. A multi-level LED security light comprising:
a light-emitting unit configured with at least a first LED load for emitting light with a first color temperature in a range between 1800K and 3000K and at least a second LED load for emitting light with a second color temperature in a range between 4000K and 6500K;
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 loading and power control unit;
a light sensing control unit;
a motion sensing unit;
a power supply unit; and
an external control unit including at least one external control device outputting at least one external control signal;
wherein the loading and power control unit includes at least a controller and an LED driver circuitry, wherein the LED driver circuitry is electrically connected with a power source of the power supply unit and the light-emitting unit for managing a DC power delivered to the light-emitting unit; wherein the LED driver circuitry is further configured with a first LED driver and a second LED driver, wherein the first LED driver comprises a first semiconductor switching device electrically connected to the first LED load and the second LED driver comprises a second semiconductor switching device electrically connected to the second LED load for managing a distribution of the DC power between delivering a first electric power to the first LED load and delivering a second electric power to the second LED load;
wherein the controller is electrically coupled with the first LED driver, the second LED driver, the light sensing control unit, the motion sensing unit, and the at least one external control device;
wherein when the light emitting-unit is in a turned-on state, the controller outputs a first control signal and a second control signal to respectively control a first conduction rate of the first semiconductor switching device and a second conduction rate of the second semiconductor switching device to respectively deliver the first electric power to the first LED load and the second electric power to the second LED load to perform different illumination modes of the multi-level LED security light characterized by different diffused light intensities and different diffused light color temperatures according to signals respectively received from the light sensing control unit, the motion sensing unit and the at least one external control device;
wherein the controller is designed with a diffused light color temperature switching scheme comprising a plurality of different diffused light color temperature performances to be activated 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 diffused light color temperature switching scheme;
wherein when a light intensity level of an ambient light detected by the light sensing control unit is lower than a first predetermined value, the loading and power control unit manages to deliver an average electric power to the light-emitting unit to operate a first illumination mode to perform a first level illumination characterized by a first diffused light intensity and a first diffused light color temperature for a first predetermined time duration; wherein when the light intensity level of the ambient light detected by the light sensing control unit is higher than a second predetermined value, the loading and power control unit manages to switch off the light-emitting unit; wherein when a motion signal is detected by the motion sensing unit, the loading and power control unit manages to increase the average electric power to the light-emitting unit to operate a second illumination mode to perform a second level illumination characterized by a second diffused light intensity and a second diffused light color temperature for a second predetermined time duration before switching back to the first illumination mode to perform the first level illumination, wherein the second diffused light intensity is always higher than the first diffused light intensity and the second diffused light color temperature is higher than or equal to the first diffused light color temperature;
wherein the at least one external control device is used for adjusting and setting at least one operating parameter of the multi-level LED security light including but not limited to at least one of the first diffused light color temperature of the first illumination mode, the second diffused light color temperature of the second illumination mode, the first predetermined time duration of the first illumination mode or the second predetermined time duration of the second illumination mode;
wherein the LEDs of the first LED load and the 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 level setting of a DC power source, 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 the LED to start emitting light and Vmax is a reference value of a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction;
wherein when each of the first LED load and the second LED load is configured with a plurality of LEDs electrically connected in series or sets of in parallel connected LEDs electrically connected in series, a working voltage across the first LED load or the second LED load is confined in a domain between a minimum voltage equal to a sum of the threshold voltages of all LEDs electrically connected in series or sets of in parallel connected LEDs electrically connected in series across each of the first LED load and the second LED load and a maximum voltage equal to a sum of the maximum operating voltages of all LEDs electrically connected in series or sets of in parallel connected LEDs electrically connected in series across each of the first LED load and the second LED load; and
wherein when the plurality of LEDs are phosphor based white light LEDs produced by coating at least one phosphor compound on surfaces of LEDs, the reference value of the threshold voltage is estimated at 2.5 volts and the reference value of the maximum operating voltage is estimated at 3.5 volts, wherein the LED has the voltage V across each LED complying with an operating constraint of 2.5 volts<V<3.5 volts and the working voltages imposed on the first LED load and the second LED load respectively represented by VN and VM are confined in domains expressed by NS×2.5 volts<VN<NS×3.5 volts and MS×2.5 volts<VM<MS×3.5 volts, wherein NS and MS are positive integrals denoting respective numbers of in series connected LEDs in the first LED load and the second LED load.