Introducing photoresistors
This section introduces you to photoresistors, which are very useful for many applications, for example, for measuring the amount of light. In this chapter, we will define what photoresistors are, their classification, and how they are connected to an electronic circuit.
A photoresistor is an electronic component made with light-sensitive material, changing its resistance according to the amount of visible light that it detects. There are different types of photoresistors. Some of them detect ultraviolet (UV) light and others detect infrared light. The latter is used in TV sets, where its infrared light sensor receives data from a remote control. Figure 4.2 shows a common photoresistor used in the examples of this chapter. The photoresistor used in this chapter detects regular light that humans can see. It does not detect infrared nor UV light.
Figure 4.2 – A typical photoresistor
From Figure 4.2, you can see that the...