Foxconn Technology Co., Ltd.

Fu Zhun Precision Industry (shen Zhen) Co., Ltd.

Da-Peng Zhang

Chin-Long Ku

Ci-Jin Mo

An LED illumination system includes a control circuit having a timing unit, a control unit and a PWM signal generating unit. The timing unit divides an operating period of an LED lamp into a plurality of time segments, and outputs a clock signal at a start of each time segment to the control unit. The control unit outputs different controlling signals corresponding to the clock signals to the PWM signal generating unit, which in turn generates different PWM signals with different duty cycles. A constant current circuit electrically connects the control circuit to the LED lamp. The constant current circuit outputs different electric currents to the LED lamp according to the PWM signals, to thereby control the LED lamp to emit light having different light intensities at the various time segments of the operating period.

LED illumination system with a power saving feature

An LED illumination system includes a control circuit having a timing unit, a control unit, a PWM signal generating unit and a micro-programmed control unit (MCU). The timing unit divides an operating period of an LED lamp into different time segments, and outputs clock signals. The control unit outputs different controlling signals corresponding to the clock signals to the PWM signal generating unit, which in turn generates different PWM signals with different duty cycles. A constant current circuit electrically connects the control circuit and outputs different electric currents to make the LED lamp emit light having different light intensities at the different time segments. The MCU is at an outside of the LED lamp and sets a program to control the timing unit, the control unit and the PWM signal generating unit.

An LED lamp protecting circuit includes an LED lamp, a constant current source and a buffer circuit. The constant current source includes positive and negative input terminals, positive and negative output terminals and a switch. The buffer circuit is connected between the negative output terminal and the LED lamp. The buffer circuit includes a charging capacitor, a first NPN transistor and a second PNP transistor. An emitting electrode of the second transistor is connected to the LED lamp. A collecting electrode of the second transistor is connected to the negative output terminal. The charging capacitor is connected between the emitting electrode of the second transistor and a ground. A collecting electrode and an emitting electrode of the first transistor are respectively electrically connected to a base electrode of the second transistor and the ground.

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Shenzhen, China

Da-Peng Zhang