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 107:
108. A multi-level LED security light comprising:
a light-emitting unit comprising at least a first LED load configured with N pieces of LEDs and at least a second LED load configured with M pieces of LEDs, wherein M and N are positive integers with a value of M being greater than or equal to a value of N, wherein the first LED load is covered by a first light diffuser and the second LED load is covered by a second light diffuser;
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 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 a light intensity or a time duration;
wherein the loading and power control unit includes 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 configured with a first LED driver electrically connected to the first LED load and a second LED driver electrically connected to the second LED load, 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;
wherein the controller is electrically coupled with the first semiconductor switching device, the second semiconductor switching device, the light sensing control unit, the motion sensing unit and the at least one external control device;
wherein 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 perform different illumination modes of the multi-level LED security light characterized by different light intensities according to signals respectively received from the light sensing control unit, the motion sensing unit and the at least one external control device;
wherein when a nighttime signal is received by the controller defined as a light intensity level of an ambient light detected by the light sensing control unit being lower than a first predetermined value, the controller outputs at least the first control signal to control at least the first conduction rate of the first semiconductor switching device to operate a first illumination mode to generate a first level illumination for a first predetermined time duration;
wherein when a daytime signal is received by the controller defined as the light intensity level of the ambient light detected by the light sensing control unit being higher than a second predetermined value, the controller operates to switch off the light-emitting unit;
wherein when a motion signal is detected by the motion sensing unit, the controller operates to output at least the second control signal to control at least the second conduction rate of the second semiconductor switching device to operate a second illumination mode to generate a second level illumination for a second predetermined time duration;
wherein the light intensity of the first level illumination is designed with a level in a range greater than 0% of a maximum light intensity but less than or equal to 50% of the maximum light intensity designed for the light-emitting unit to characterize the first level illumination, wherein the light intensity of the second level illumination is designed with a level in a range greater than 50% of the maximum light intensity but less than or equal to 100% of the maximum light intensity to characterize the second level illumination being higher than the first level illumination;
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; 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 imposed on each of the first LED load and the second LED load is confined in a domain between a minimum voltage equal to the sum of the threshold voltages of all LEDs electrically connected in series or sets of in parallel connected LEDs electrically connected in series and a maximum voltage equal to the sum of the maximum operating voltages of all LEDs electrically connected in series or sets of in parallel connected LEDs electrically connected in series; and
wherein when the first LED load and the second LED load are configured with a plurality of white light LEDs produced by coating at least one phosphor compound on surfaces of LEDs, said reference value of said threshold voltage Vth is estimated at 2.5 volts and said reference value of said maximum operating voltage Vmax is estimated at 3.5 volts subject to an operating condition that a temperature of each LED connecting pin is controlled at or below 80 degree centigrade, wherein said voltage V across each LED of said plurality of LEDs complies with an operating constraint of 2.5 volts<V<3.5 volts, wherein the working voltage VN imposed on the first LED load is required to operate in a domain NS×2.5 volts<VN<NS×3.5 volts, and the working voltage VM imposed on the second LED load is required to operate in a domain MS×2.5 volts<VM<MS×3.5 volts, wherein NS and MS respectively denoting the numbers of in series connected LEDs in the first LED load and the second LED load, wherein NS≤N and MS≤M.