Automatic Night Light Circuit Using NAND gate Chip.

Automatic Night Light Circuit Using NAND gate Chip.

In this project, we will build a Night Light circuit using a NAND gate chip. A light detector circuit is a circuit that can detect light. When a bright light shines on the circuit, such as from a flashlight, we will make it so that a LED turns on. The circuit is very basic. The component that will allow us to detect light is a photo resistor (LDR). We will use a photoresistor's light-sensing ability to detect whether the circuit is exposed to darkness or bright light. How this works is that a photo resistor's resistance changes in proportion to the amount of light it is exposed to. In darkness, it has very high resistance. In bright light, its resistance drops dramatically. If placed in a voltage divider circuit with a fixed resistor, we can exploit this resistance-altering behavior's so that when connected to a NAND gate, we can produce a logic HIGH output when the photo resistor is exposed to the NAND gate. We can control circuit light in connect the photo-resister with NAND gate and according to their truth table. It will work in the circuit in such a way that as the amount of sun light in the sensor increases, the light of the LED will decrease, on the other hand, the less the amount of sun light of the LED light will increase. During this process, the LED Will light up completely and the LED will be completely off in the face of sunlight.

Uses of the Automatic Night Light
It’s automatically switches ON lights when the sunlight goes below the visible region of our eyes. (e.g in evening after Sunset). It automatically switches OFF lights when Sunlight fall on it ( i.e on LDR ) e.g in morning, by using a sensor called LDR (Light Dependent Resistor) which senses the light just like our eyes.

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