Two-level led security light with motion sensor

An LED security light, comprising:

• a power supply unit;
• a light-emitting unit, including an LED load;
• a loading and power control unit;
• a light sensing control unit;
• a motion sensing unit, including at least one motion sensor;
• and
• a time setting unit;
• wherein the loading and power control unit comprises a controller and a switching circuitry, and the controller is electrically coupled with the switching circuitry;
• wherein the switching circuitry is electrically coupled with a power source of the power supply unit and the light-emitting unit, and the power source is a DC power source configured in the power supply unit;
• wherein the switching circuitry comprises at least one unidirectional semiconductor switching device;
• wherein the controller outputs pulse width modulation (PWM) signals to control average conduction rates of the switching circuitry for delivering different average electric currents from the power supply unit to drive the LED load of the light-emitting unit such that the light-emitting unit respectively generates illuminations of different light intensities for performing different illumination modes activated by the light sensing control unit, the motion sensing unit and the time setting unit;
• wherein at dusk when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the light-emitting unit is turned on by the loading and power control unit activated by the light sensing control unit to perform a first illumination mode with a first level illumination and with the motion sensing unit being in a deactivated state, and the first illumination mode continues for a first predetermined time duration;
• wherein upon a maturity of the first predetermined time duration the loading and power control unit manages to cutoff the average electric current delivered to the LED load of the light-emitting unit and at the same time the motion sensing unit is activated;
• wherein when a motion signal is detected by the motion sensing unit, the loading and power control unit manages to deliver an average electric current to the LED load of the light-emitting unit to perform a second illumination mode with a second level illumination for a second predetermined time duration before being switched back to the turned off state;
• wherein at dawn when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the light-emitting unit is switched off by the loading and power control unit;
• wherein the time setting unit is used for adjusting and setting at least a time length of at least one of the first predetermined time duration and the second predetermined time duration;
• wherein the LED load in conjunction with the DC power source is designed with an adequate combination of in series and in parallel connections such that an electric current passing through each LED of the LED load remains at an adequate level, and a working voltage V across each LED complies with a constraint of Vth<V<Vmax featuring electrical characteristics of the LED;
• wherein Vth is a minimum 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 to LED construction;
• and
• wherein the controller comprises at least a programmable integrated circuit device or an application specific integrated circuit.

An LED security light, comprising:

• a power supply unit;
• a light-emitting unit, including an LED load;
• a loading and power control unit;
• a light sensing control unit;
• a motion sensing unit, including at least one motion sensor;
• and
• a time setting unit;
• wherein the loading and power control unit comprises a controller and a switching circuitry, and the controller is electrically coupled with the switching circuitry;
• wherein the switching circuitry is electrically coupled with a power source of the power supply unit and the light-emitting unit, and the power source is a DC power source configured in the power supply unit;
• wherein the switching circuitry comprises at least one unidirectional semiconductor switching device;
• wherein the controller outputs pulse width modulation (PWM) signals to control average conduction rates of the switching circuitry for delivering different average electric currents from the power supply unit to drive the LED load of the light-emitting unit such that the light-emitting unit respectively generates illuminations of different light intensities for performing different illumination modes activated by the light sensing control unit, the motion sensing unit and the time setting unit;
• wherein at dusk 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 turn on the light emitting unit to perform a low level illumination mode comprising at least a first level illumination for a first predetermined time duration;
• wherein when a motion signal is detected by the motion sensing unit, the loading and power control unit operates to increase the average electric current delivered to the LED load of the light-emitting unit to perform a high level illumination mode for a preset time period before being switched back to the low level illumination mode;
• wherein the light intensity of the high level illumination mode is higher than the light intensity of the low level illumination mode;
• wherein at dawn when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the light-emitting unit is switched off by the loading and power control unit;
• wherein the time setting unit is used for adjusting and setting at least a time length of at least one of the first predetermined time duration of the low level illumination mode and the preset time period of the high level illumination mode;
• wherein the LED load in conjunction with the DC power source is designed with an adequate combination of in series and in parallel connections such that an electric current passing through each LED of the LED load remains at an adequate level, and a working voltage V across each LED of the LED load complies with a constraint of Vth<V<Vmax featuring electrical characteristics of the LED;
• wherein Vth is a minimum 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 to LED construction;
• and
• wherein the controller comprises at least a programmable integrated circuit device or an application specific integrated circuit.

An LED security light, comprising:

• a power supply unit;
• a light-emitting unit, including an LED load;
• a loading and power control unit;
• a light sensing control unit;
• a motion sensing unit, including at least one motion sensor;
• and
• a time setting unit;
• wherein the loading and power control unit comprises a controller and a switching circuitry, and the controller is electrically coupled with the switching circuitry;
• wherein the switching circuitry is electrically coupled with a power source of the power supply unit and the light-emitting unit, and the power source is a DC power source configured in the power supply unit;
• wherein the switching circuitry comprises at least one unidirectional semiconductor switching device;
• wherein the controller outputs pulse width modulation (PWM) signals to control average conduction rates of the switching circuitry for delivering different average electric currents from the power supply unit to drive the LED load of the light-emitting unit such that the light-emitting unit respectively generates illuminations of different light intensities for performing different illumination modes for respective predetermined time durations activated by the light sensing control unit, the motion sensing unit and the time setting unit;
• wherein the time setting unit is used for adjusting and setting at least a time length of the predetermined time durations;
• wherein the power supply unit is a structure of DC power sources comprising an AC/DC power converter to convert AC power into DC powers required for operating the LED security light;
• wherein the LED load in conjunction with the DC power source is designed with an adequate combination of in series and in parallel connections such that an electric current passing through each LED of the LED load remains at an adequate level, and a working voltage V across each LED complies with a constraint of Vth<V<Vmax featuring electrical characteristics of the LED;
• wherein Vth is a minimum 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 to LED construction;
• and
• wherein the controller comprises at least a programmable integrated circuit device or an application specific integrated circuit.

An LED security light, comprising:

• a power supply unit;
• a light-emitting unit, including an LED load;
• a loading and power control unit;
• a light sensing and control unit;
• and
• a time setting unit;
• wherein the loading and power control unit comprises a controller and a switching circuitry, the controller is electrically coupled with the switching circuitry, the switching circuitry is electrically coupled between a power source and the light-emitting unit, and the power source is a DC power source configured in the power supply unit;
• wherein with the switching circuitry the light-emitting unit is turned on or turned off by the loading and power control unit, and the switching circuitry comprises at least one unidirectional semiconductor switching device;
• wherein the controller outputs pulse width modulation (PWM) signals to control average conduction rates of the switching circuitry for delivering different average electric currents from the power supply unit to drive the LED load of the light-emitting unit such that the light-emitting unit respectively generates illuminations of different light intensities for performing different illumination modes activated by the light sensing control unit and the time setting unit;
• wherein at dusk when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the light-emitting unit is turned on by the loading and power control unit to perform a first illumination mode for a predetermined time duration set by the time setting unit, and then the controller manages to change the lighting performance of the LED security light from the first illumination mode to a second illumination mode;
• wherein the light intensity of the second illumination mode is lower than the light intensity of the first illumination mode;
• wherein at dawn when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the light-emitting unit is turned off by the controller;
• wherein the time setting unit is used for adjusting and setting a time length of the predetermined time duration;
• wherein the LED load in conjunction with the DC power source is designed with an adequate combination of in series and in parallel connections such that an electric current passing through each LED of the LED load remains at an adequate level, and a working voltage V across each LED complies with a constraint of Vth<V<Vmax featuring electrical characteristics of the LED;
• wherein Vth is a minimum 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 to LED construction;
• and
• wherein the controller comprises at least a programmable integrated circuit device or an application specific integrated circuit.

An LED security light, comprising:

• a power supply unit;
• a light-emitting unit, including an LED load;
• a loading and power control unit;
• and
• a light sensing control unit;
• wherein the loading and power control unit comprises a controller and a switching circuitry, the controller is electrically coupled with the switching circuitry, the switching circuitry is electrically coupled between a power source and the LED load of the light-emitting unit, and the power source is a DC power source configured in the power supply unit;
• wherein with the switching circuitry the light-emitting unit is turned on or turned off by the loading and power control unit, and the switching circuitry comprises at least one unidirectional semiconductor switching device;
• wherein at dusk when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the controller of the loading and power control unit outputs a control signal to conduct the switching circuitry to deliver an average electric current to the LED load such that to turn on the light-emitting unit for generating an illumination;
• wherein at dawn when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the controller of the loading and power control unit outputs a control signal to cutoff the switching circuitry to turn off the light-emitting unit;
• wherein the LED load in conjunction with the DC power source is designed with a configuration of in series or in parallel connections such that an electric current passing through each LED of the LED load remains at an adequate level, and a working voltage V across each LED of the LED load complies with a constraint of Vth<V<Vmax featuring electrical characteristics of the LED;
• wherein Vth is a minimum 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 to LED construction;
• and
• wherein the controller comprises at least an integrated circuit device programmable for generating the control signals or an application specific integrated circuit customized for generating the control signals.

An LED security light, comprising:

• a power supply unit;
• a light-emitting unit, including an LED load;
• a loading and power control unit;
• a light sensing control unit;
• and
• an external control unit;
• wherein the loading and power control unit comprises a controller and a switching circuitry, the controller is electrically coupled with the switching circuitry, the switching circuitry is electrically coupled between a power source and the LED load of the light-emitting unit, and the power source is a DC power source configured in the power supply unit;
• wherein with the switching circuitry the light-emitting unit is turned on or turned off by the loading and power control unit, and the switching circuitry comprises at least one unidirectional semiconductor switching device, wherein the controller outputs control signals to control average conduction rates of the switching circuitry for delivering different average electric currents from the power supply unit to drive the LED load of the light-emitting unit such that the light-emitting unit respectively generates illuminations of different light intensities for performing at least a first illumination mode and a second illumination mode activated by the light sensing control unit and the external control unit;
• wherein the external control unit is a power interruption detection circuitry electrically coupled to the controller for detecting a short power interruption signal, wherein the controller controls the switching circuitry in response to the short power interruption signal detected to alternately switch the light-emitting unit between performing a first illumination mode and performing a second illumination mode, wherein the light intensity of the first illumination mode is higher than the light intensity of the second illumination mode;
• wherein at dusk when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the light-emitting unit is turned on by the loading and power control unit to perform the first illumination mode;
• wherein whenever the short power interruption signal is detected by the external control unit, the controller operates to alternately switch the light-emitting unit between performing the first illumination mode and performing the second illumination mode;
• wherein at dawn when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the controller of the loading and power control unit operates to cutoff the switching circuitry to turn off the light emitting unit. wherein the LED load in conjunction with the DC power source is designed with a configuration of in series or in parallel connections such that an electric current passing through each LED of the LED load remains at an adequate level, and a working voltage V across each LED of the LED load complies with a constraint of Vth<V<Vmax featuring electrical characteristics of the LED;
• wherein Vth is a minimum 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 to LED construction;
• and
• wherein the controller comprises at least an integrated circuit device programmable for generating the control signals or an application specific integrated circuit customized for generating the control signals.

An LED motion sensing security light, comprising:

• a power supply unit;
• a light-emitting unit, including an LED load;
• a loading and power control unit;
• a light sensing control unit;
• a motion sensing unit, including at least one motion sensor;
• and
• a time setting unit;
• wherein the loading and power control unit comprises a controller and a switching circuitry, and the controller is electrically coupled with the switching circuitry;
• wherein the switching circuitry is electrically coupled with a power source of the power supply unit and the light-emitting unit, and the power source is a DC power source configured in the power supply unit;
• wherein the switching circuitry comprises at least one unidirectional semiconductor switching device;
• wherein the controller outputs a pulse width modulation (PWM) signal to control a conduction rate of the switching circuitry for transmitting an average electric current from the power source to drive the LED load of the light-emitting unit to generate an illumination activated by the motion sensing unit for performing a motion sensing illumination mode;
• wherein the time setting unit is used for adjusting and setting at least a time length of the predetermined time durations;
• wherein the power supply unit is a structure of DC power sources comprising an AC/DC power converter to convert AC power into DC powers required for operating the LED security light;
• wherein the LED load in conjunction with the DC power source is designed with an adequate combination of in series and in parallel connections such that an electric current passing through each LED of the LED load remains at an adequate level, and a working voltage V across each LED complies with a constraint of Vth<V<Vmax featuring electrical characteristics of the LED;
• wherein Vth is a minimum 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 to LED construction;
• wherein at dusk 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 switch on the light-emitting unit;
• wherein when a motion signal is detected by the motion sensing unit, the loading and power control unit manages to conduct the switching circuitry to deliver the average electric current to drive the LED load for generating the illumination for a predetermined time duration preset by the time setting unit;
• wherein when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the light-emitting unit is turned off by the controller.