How Does An LDR Work And What Are Its Applications

The LDR (Light Dependent Resistor) is also known as a photoconductor, photo resistor, photoconductive cell or simply photocell. However, it is typically called by the term photocell at present. The LDR is utilized as an inexpensive photosensitive element and has a wide usage in various applications at present. In the subsequent paragraphs, we will throw some light on how LDR functions and also some of its uses.

How does it work?

The fundamentals of the working principles of an LDR can be easily understood by virtually any person without any need to enter into complex details. First of all, one must comprehend the fact that an electric current is actually the movement of the electrons within a particular material. There are lots of free electrons in the good conductors and the actions of a potential difference are responsible for moving them in a specific direction.

Since there are not many free electrons in insulators having a high resistance, it is quite difficult for current to flow by drifting them. As a matter of fact, a Light Dependent Resistor is made out of any type of semiconductor material having a high resistance.

The number of free electrons which are able to move is quite less and therefore it has a high resistance; most of the electrons are not able to move since they are locked into the crystal lattice. Consequently, there is a high LDR resistance in this particular condition. The lattice absorbs the light photons when light falls on the semiconductor and this results in the transfer of energy to the electrons. In this way, some of them are able to break free from the lattice by getting energized and this enables them to conduct electricity.

Thus, the semiconductor's resistance along with the overall LDR resistance gets lowered. An increasing number of electrons get released as more light falls on the semiconductor which enables them to conduct electricity and therefore there is further lowering of resistance.

Usages

Due to its simple structure, low price plus tough features, the LDR is nowadays used in lots of electronic circuit designs. In fact, it is appropriate for many applications despite the fact that it lacks several features which are present in the phototransistor and the photodiode. It has got a wide usage in circuits like smoke or flame detectors, card readers, burglar alarms, and photographic meters and so on.

Hopefully, this article has provided you with adequate information regarding what exactly is an LDR, its working principles as well as its applications. In case you have further queries, just go online and get the necessary information from the web.