US 8,866,392 B2 · Two-level LED security light with motion sensor

Abstract

A two-level LED security light with a motion sensor. At night, the LED is turned on for a low level illumination. When the motion sensor detects any intrusion, the LED is switched from the low level illumination to a high level illumination for a short duration time. After the short duration time, the LED security light returns to the low level illumination for saving energy. The LED security light includes a power supply unit, a light sensing control unit, a motion sensing unit, a loading and power control unit, and a lighting-emitting unit. The lighting-emitting unit includes one or a plurality of LEDs which may be turned-on or turned-off according to the sensing results from the light sensing control unit. When the motion sensing unit detects an intrusion, the illumination of the LED security light can be immediately turned on to the high level to scare away the intruder.

Claims14

Dependent claims

A two-level LED security light, comprising:

a light emitting unit;
a loading and power control unit;
a light sensing control unit;
a motion sensing unit;
and
a power supply unit;
wherein the light emitting unit comprises at least one LED;
wherein the loading and power control unit comprises a microcontroller electrically coupled with a transistor, wherein the transistor is electrically connected in series with the power supply unit and the light emitting unit, wherein the microcontroller with program codes outputs a pulse width modulation (PWM) signal to a gate electrode of the transistor to control the conduction period Ton and the cut-off period Toff of the transistor for delivering different average electric currents from the power supply unit to drive the light emitting unit for generating different illuminations, wherein the microcontroller controls the transistor respectively to have a short Ton and a long Ton of the conduction period such that the light-emitting unit respectively generates a low level and a high level illumination according to the received signal outputted from the light sensing control unit and the motion sensing unit.

5 more elements

A two-level security LED light, comprising:

a power supply unit;
a light sensing control unit;
a motion sensing unit;
a loading and power control unit;
and
a light-emitting unit;
wherein the light-emitting unit comprises a plurality of series-connected LEDs;
wherein the loading and power control unit comprises a microcontroller electrically coupled with a first switching device and a second switching device, wherein the first switching device for delivering a constant current to drive the LEDs is electrically connected in series with the power supply unit and the plurality of series-connected LEDs in the light emitting unit, the second switching device for serving as an electric current bypass path when being turned on is electrically connected in parallel with some LEDs of the plurality of series-connected LEDs in the light emitting unit, wherein the microcontroller with program codes outputs signals for controlling the on and off switching operations of the switching devices to drive the light-emitting unit for generating different illuminations by activating different numbers of LEDs, wherein a high level illumination is generated by turning on all LEDs in the light-emitting unit with the first switching device being turned on and the second switching device being turned off simultaneously, and a low level illumination is generated by turning on a portion of LEDs in the light-emitting unit with both the first switching device and the second switching device being turned on simultaneously, wherein when an ambient light detected by the light sensing control unit is lower than a predetermined value, the loading and power control unit turns on a portion of LEDs in the light-emitting unit to generate a low level illumination;
when the ambient light detected by the light sensing control unit being higher than the predetermined value, the loading and power control unit turns off all the LEDs in the light-emitting unit;
when an intrusion detected by the motion sensing unit, the loading and power control unit turns on all the LEDs in the light-emitting unit to generate a high level illumination for a predetermined duration;
wherein the electric current through the driven LED in the light-emitting unit is constant.

8 more elements

A two-level security light, comprising:

a power supply unit;
a light sensing control unit;
a motion sensing unit;
a loading and power control unit;
a zero-crossing detection circuit;
and
a light-emitting unit;
wherein the light-emitting unit comprises a phase controller and an alternating current (AC) lighting source, the phase controller being series-connected to the AC lighting source and being connected to an AC power source;
wherein the loading and power control unit comprises a microcontroller for writing operation program to control a conduction period of the phase controller thereby to adjust the average power of the AC lighting source;
wherein when an ambient light detected by the light sensing control unit is lower than a predetermined value, the light-emitting unit is turned on by the loading and power control unit thereby to generate a low level illumination and when the ambient light detected by the light sensing control unit is higher than the predetermined value, the light-emitting unit is turned off by the loading and power control unit;
when an intrusion is detected by the motion sensing unit, the loading and power control unit increases the average power of the light-emitting unit and a high level illumination is generated for a predetermined duration.

8 more elements

Dependencies are inferred from the claim text.

Two-level LED security light with motion sensor

Life of this patent

Two-level LED security light with motion sensor

Life of this patent

Abstract

Claims14