Two-level LED security light with motion sensor

An LED security light comprising:

• a light-emitting unit comprising a plurality of LEDs divided into two LED loads connected in parallel, including a first LED load with N number LEDs emitting light with a low light color temperature and a second LED load with M number LEDs emitting light with a high light color temperature, wherein M and N are positive integers;
• 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 a first external control device outputting at least one first external control signal to tune and to select the diffused light color temperature;
• wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the switching circuitry is electrically coupled between at least one DC power source of the power supply unit and the light-emitting unit for controlling and delivering at least one DC power to the light-emitting unit, wherein the switching circuitry comprises a first semiconductor switching device electrically connected to the first LED load and 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 at least the first 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 and a second control signal to control a second conduction rate of the second semiconductor switching device to respectively deliver a first electric power to the first LED load and a second electric power to the second LED load to generate the diffused light with the diffused light color temperature thru the diffuser according to the at least one first external control signal;
• wherein for tuning the diffused light color temperature to a lower diffused light color temperature, the controller upon receiving the at least one first external control signal 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 diffused light intensity generated by the light-emitting unit remains essentially 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 upon receiving the at least one first external control signal 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 essentially unchanged while the diffused light color temperature is accordingly adjusted to the higher diffused light color temperature;
• wherein when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the loading and power control unit operates to activate the motion sensing unit;
• wherein when a motion intrusion is detected by the motion sensing unit, the loading and power control unit operates to deliver an electric power to the light-emitting unit to generate a high level illumination with a selected diffused light color temperature according to a sensing signal received from the motion sensing unit for a predetermined time duration before resuming to a turned off state of the light-emitting unit;
• wherein when 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 deactivate the motion sensing unit and turn off all LEDs of the light-emitting unit;
• 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 at least one DC power an electric current passing through each LED of the first LED load and each LED of the second LED load remains at an adequate level such that a voltage V across each LED complies with an operating constraint of Vth<V<Vmax featuring electrical characteristics of a LED, where Vth is a threshold voltage required to trigger the LED to start emitting light and Vmax is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.

A method of configuring an LED lighting device with a tunable diffused light color temperature, comprising:

• using a light-emitting unit comprising a plurality of LEDs being divided into at least two LED loads including at least a first LED load with N number LEDs emitting light with a low color temperature and at least a second LED load with M number LEDs emitting light with a high color temperature;
• the first LED load and the second LED load being electrically connected in parallel;
• using a light diffuser covering the first LED load and the second LED load to create a diffused light with a diffused light color temperature;
• using an LED driver circuitry electrically coupled between a power source and the light-emitting unit to output at least one DC power to the light-emitting unit;
• using a first semiconductor switching device electrically connected between the LED driver circuitry and the first LED load to control a power level of a first electric power delivered to the first LED load;
• using a second semiconductor switching device electrically connected between the LED driver circuitry and the second LED load to control a power level of a second electric power delivered to the second LED load;
• using a controller, electrically coupled with the first semiconductor switching device and the second semiconductor switching device to respectively control a first conduction rate of the first semiconductor switching device and a second conduction rate of the second semiconductor switching device;
• using at least a first external control device electrically coupled with the controller to output at least one first external control signal to tune and to select a corresponding diffused light color temperature performance;
• wherein when the light-emitting unit is in a turned on state, the controller outputs the first control signal to control the first conduction rate of the first semiconductor switching device and the second control signal to control the 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 generate the diffused light with the diffused light color temperature thru the diffuser according to the at least one first external control signal;
• wherein for tuning the diffused light color temperature to a lower diffused light color temperature, the controller upon receiving the at least one first external control signal 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 diffused light intensity generated by the light-emitting unit remains essentially 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 upon receiving the at least one first external control signal 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 essentially unchanged while the diffused light color temperature is accordingly adjusted to the higher diffused light color temperature;
• wherein the first LED load and 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 at least one DC power an electric current passing through each LED of the first LED load and each LED of the second LED load remains at an adequate level such that a voltage V across each LED complies with an operating constraint of Vth<V<Vmax featuring electrical characteristics of a LED, where Vth is a threshold voltage required to trigger the LED to start emitting light and Vmax is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.

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 low color temperature and at least a second LED load with M number LEDs emitting light with a high color temperature;
• the first LED load and the second LED load being electrically connected in parallel;
• a light diffuser covering the first LED load and the second LED load to create a diffused light with a diffused light color temperature;
• an LED driver circuitry electrically connected to at least one power source to output at least one DC power to the light-emitting unit;
• a first semiconductor switching device electrically connected between the LED driver circuitry and the first LED load;
• a second semiconductor switching device electrically connected between the LED driver circuitry and the second LED load;
• at least a first external control device to output at least one first external control signal to tune and to select a corresponding diffused light color temperature performance;
• and
• a controller, electrically coupled with the first semiconductor switching device, the second semiconductor switching device and at least the first external control device;
• wherein when the light-emitting unit is in a turned on state, the controller outputs a first control signal to control a first conduction rate of the first semiconductor switching device and a second control signal to control the second conduction rate of the second semiconductor switching device to respectively deliver a first electric power to the first LED load and a second electric power to the second LED load to generate the diffused light with the diffused light color temperature thru the diffuser according to the at least one first external control signal;
• wherein for tuning the diffused light color temperature to a lower diffused light color temperature, the controller upon receiving the at least one first external control signal 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 diffused light intensity generated by the light-emitting unit remains essentially 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 upon receiving the at least one first external control signal 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 essentially unchanged while the diffused light color temperature is accordingly adjusted to the higher diffused light color temperature;
• wherein the first LED load and 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 at least one DC power an electric current passing through each LED of the first LED load and each LED of the second LED load remains at an adequate level such that a voltage V across each LED complies with an operating constraint of Vth<V<Vmax featuring electrical characteristics of a LED, where Vth is a threshold voltage required to trigger the LED to start emitting light and Vmax is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.

An LED lighting device comprising:

• a light-emitting unit comprising a plurality of LEDs divided into two LED loads connected in parallel, including a first LED load with N number of LEDs emitting light with a low light color temperature and a second LED load with M number of LEDs emitting light with a high light color temperature, wherein M and N are positive integers;
• a light diffuser covering the first LED load and the second LED load to create a diffused light with a diffused light color temperature;
• an LED driver circuitry electrically coupled between a power source
• and the light-emitting unit to output a DC power;
• a loading and power control unit configured with at least a power loading circuitry electrically coupled between the LED driver circuitry and the light-emitting unit to operate a plurality of different power loading options for respectively distributing and loading the DC power between a first electric power delivered to the first LED load and a second electric power delivered to the second LED load, wherein each of the plurality of different power loading options is configured with a paired combination of the first electric power and the second electric power for generating the diffused light with the diffused light color temperature to form a diffused light color temperature switching scheme comprising a plurality of different diffused light color temperature performances for selection;
• and
• an external control unit including at least a first external control device for activating the diffused light color temperature switching scheme and executing a power loading option for performing a corresponding diffused light color temperature performance;
• 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 an adequate level such that a voltage V across each LED complies with an operating constraint of Vth<V<Vmax featuring electrical characteristics of a LED, where Vth is a threshold voltage required to trigger the LED to start emitting light and Vmax is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.