A photocell, also known as a photoresistor or light-dependent resistor (LDR), is a type of resistor that changes its resistance based on the amount of light that falls on it. The resistance of a photocell decreases as the intensity of light increases and vice versa. This makes photocells useful in a variety of applications, including light sensors, streetlights, camera light meters, and burglar alarms.
Photocells are made of materials such as cadmium sulfide, cadmium selenide, or silicon that exhibit photoconductivity. Photoconductivity is the ability of a material to change its electrical conductivity when exposed to light. When light strikes the surface of a photocell, it releases electrons, which increase the flow of current through the cell.
Photocells can be used in various ways to control electrical circuits. For example, they can be used to switch on a light when it gets dark and switch it off when it gets light again. They can also be used as a sensor to control the brightness of a display screen or to control the speed of a motor.
Photocells are commonly used in outdoor applications due to their ability to withstand harsh environmental conditions such as extreme temperatures, humidity, and UV radiation. They are also relatively inexpensive, making them a cost-effective solution for many applications.
In conclusion, photocells are versatile and widely used components in the electronics industry. They have simple and low-cost construction, making them a popular choice for many applications, including light sensors, streetlights, camera light meters, burglar alarms, and more.
Post time: Feb-07-2023