Abstract: Disclosed is an LED lighting circuit based on PWM, including a power source, a control circuit and an LED light-emitting element, and further including a non-light-emitting load element. The non-light-emitting load element is connected in parallel to the LED light-emitting element, the power source is connected to a constant-current source, the constant-current source supplies power to the LED light-emitting element and the non-light-emitting load element, and when the constant-current source is in a current rising or falling phase, the control circuit controls an LED light-emitting element loop to be disconnected, and controls a non-light-emitting load element loop to be connected; and when the current of the constant-current source is in a steady state, the control circuit controls the non-light-emitting load element loop to be disconnected, and controls the LED light-emitting element loop to be connected.

Abstract: A method and a device for integrated network intelligent security monitoring and alarming are provided. The device includes a front cover (6) and a rear cover (10). A light-emitting diode (LED) infrared lighting circuit board (3) is installed on the front cover (6). An embedded microprocessor main control module board (16) and a wired and wireless broadband network module board (19), an image sensor module board (31), a wireless remote controller/alarm sensor signal receiving module board (22), a general packet radio service (GPRS) mobile phone short message and multimedia message transceiver module board (27), a siren control circuit board (21), and a piezoelectric speaker (20) electrically connected to the embedded microprocessor main control module board (16) are installed in an installing cavity between the front cover (6) and the rear cover (10). The method is simple, and the device has advantages of high integration, a small volume, multiple functions, and convenient installation and use.

Abstract: A method and a device for integrated network intelligent security monitoring and alarming are provided. The device includes a front cover (6) and a rear cover (10). A light-emitting diode (LED) infrared lighting circuit board (3) is installed on the front cover (6). An embedded microprocessor main control module board (16) and a wired and wireless broadband network module board (19), an image sensor module board (31), a wireless remote controller/alarm sensor signal receiving module board (22), a general packet radio service (GPRS) mobile phone short message and multimedia message transceiver module board (27), a siren control circuit board (21), and a piezoelectric speaker (20) electrically connected to the embedded microprocessor main control module board (16) are installed in an installing cavity between the front cover (6) and the rear cover (10). The method is simple, and the device has advantages of high integration, a small volume, multiple functions, and convenient installation and use.