Working Principle Of Small Night Light

(1) The human body sensing night light, which has an infrared sensing switch inside, can achieve the goal of turning on the lights when people come and off when people go. It is composed of capacitive voltage reduction, bridge rectification, filtering, and light controlled switching circuits, which is relatively energy-saving. Then, it is more convenient to wake up at night.
(2) Light sensing intelligent light. In light sensing, as we usually see in the corridor, there is a working principle in which a sensor will drive to the surrounding light. After the light reaches a certain measure, the small night light will naturally go out. When the light is not sensed, the night light will naturally turn on.
(3) A common luminous night light, C1, R1, and D1 through D4, constitutes a resistance capacitance step-down rectifier circuit that converts high voltage AC power into low voltage DC power, and C2 is a filter capacitor. R2 is a photosensitive resistor. When exposed to light, the resistance value decreases, and the base potential of Q1 increases. When a certain potential is reached, Q1 is turned on. When R2 is not exposed to light, the resistance value increases, the base potential of Q1 decreases, and Q1 turns off. When making night lights, R2 should be swapped with R3 so that the lights turn on when there is no light and turn off when there is light. The principle of the small night light is that it outputs an oscillating pulse signal from the three legs of the 1o, which is amplified by V3-V5 and drives the light controlled small night light to emit light. Adjust the resistance value of RP1, change the operating frequency of the self-excited multivibrator, and control the size of the output pulse duty ratio to adjust the brightness of the light controlled night light.