A photocell is an electronic component that detects the presence or absence of light. It is often used in automation and control systems to trigger an action based on light levels. In this article, we’ll look at the different types of photocell and their practical applications.
What’s a photocell for?
A photocell is an electronic component that detects the presence or absence of light. They are used in a wide range of fields, including automation, security, robotics and lighting.
Photocells operate on the principle of converting light energy into electrical energy. The photocell consists of a diode that emits electrons when exposed to a light source. These electrons are then captured by a metal plate opposite the diode, generating an electric current.
The most common applications for photocells are automatic lighting systems. These devices automatically switch lights on and off according to ambient light levels. They are often used in underground parking lots, streets and other public spaces.
Photocells are also very useful for ensuring the safety of people and property. For example, they can be integrated into automatic doors to detect opening and closing, and into certain anti-intrusion systems to detect any attempt to break into a building.
Finally, there are also more specific applications, such as quality control in the food industry, or monitoring the filling level of grain silos.
Ultimately, the photocell is a key component in many industrial fields, as well as in our daily lives. Its ability to transform light into electrical energy enables precise detection of the presence or absence of light, making it an indispensable tool for many applications.
Some types of photocell
There are several types of photocell. Each type offers specific advantages and disadvantages in terms of precision, range and operating environment. Here’s a practical guide to understanding the different types of photocell:
Reflex photocell
The reflex photocell uses a built-in light source to emit a beam of light that is reflected by a target object back to the photoelectric sensor located on the same unit. It is commonly used to detect opaque objects such as metal or plastic.
Barrier photocell
The barrier photocell consists of a transmitter-receiver pair physically separated by a fixed distance. When an object passes between the two components, it partially or totally blocks the transmission of the light beam between them, triggering detection. This type is often used for precise measurement of distances and dimensions.
Slot photocell
The slit photocell uses a narrow slit as a transmitter and a receiver opposite as a photoelectric sensor. When an object passes in front of the slit, it blocks part of the light, triggering detection. It is commonly used to detect thin objects such as sheets of paper or plastic film.
Proximity photocell
The proximity photocell uses a magnetic or electric field to detect metal objects. It can be used in harsh environments where other types of photocell would not work.
In short, the choice of photocell type will depend on the type of object to be detected, as well as environmental and operational conditions. By understanding the different types available on the market and their respective advantages, you can choose the one best suited to your specific application.
What about Prastel?
At Prastel, we offer 3 applications for photocells:
- surface-mounted (on the wall),
- recessed (hole in wall),
- recessed in the door jamb.
Our full range of products includes :
- fixed cells (one opposite the other),
- directional cells (orienting the beam to simplify product installation),
- classic plastic cells for residential and collective applications,
- vandal-proof cells for industrial environments (with a metal cover for protection).
We also offer 2 types of power supply for photocells: cable or battery. This is useful information, because if you don’t want to make a trench to run the wires to your customers, you can opt for a battery-powered model (available on plastic cells only).
Please do not hesitate to contact us for further information.
