Before I dive into giving you a photocell application, allow me to define a photocell as an electrical device that is controlled by light. How does light work with a photocell?. A photocell is a light-controlled resistor. Current will flow in direct proportions to the light intensity. It should be noted that there are three main types of photocells, these are:
- Photo-emissive cell,
- Photo-voltaic cell,
- Photo-conductive cell.
Table of contents
- Table of contents
- Photocell application.
- Summary of Photocell Application.
A photocell has a lot of applications in a day to day activities below is a list of some applications.
A list of photocell application
- Photocells are used in automatic switching of lights to activate whenever it gets dark, and the switching on/off of streetlights mainly depends on the time of the day whether it is day or night.Learn how to wire a photocell to multiple lights.
- They are used as timers in a running race to calculate the runner’s speed.
- Photocells are used to count the vehicles on the road.
- In lux meters to decide the light intensity.
- They can be used as switches as well as sensors
- In burglar alarms to protect from a thief.
- Photocells are used in robotics, wherever they direct robots to hide from view in the dark, otherwise to follow a beacon or line.
- They are also used in exposure meters which can be used with a camera for knowing the correct time of exposure to get a good photo.
- Photocells are used in the sound reproduction which can be recorded on a movie film.
- Photoelectric cells are used for reproducing sound in cinematography.You can know the history of sound production in movies production
- They are used for controlling the temperature of furnaces.
- Photoelectric cells are used for automatic switching on and off the street lights.
- Photoelectric cells are used in the study of temperature and spectra of stars.
- Photoelectric cells are also used in obtaining electrical energy from sunlight during space travel.
- To open doors automatically in a building such as banks or other commercial buildings or offices
- To count items running on a conveyer belt.
- In counters,to count objects or persons.
- control of central heating burners
- scanner reading bar codes
- stopping conveyer belt
- They are used in complexion meters.
- They are used in photoelectric sorters to sort out the objects
- They are used in meterology to record day-light.
Photocell application in Burglar Alarm
The photocell is also used in burglar alarms. The main purpose of this instrument is to alert you when thieves intrude on your premises. This device is mainly employed for detecting intruders.
A burglar alarm works with a photocell and infrared light as a source light. The light coming from the infrared source falls on the photocell which produces a constant photoelectric effect. When there is any interruption in the direction of infrared light by the thief. The light that falls on the photocell is cut off, as a result, no photoelectric effect takes place. This activates the relay circuit to turn on the siren.
Photocell application in Exposure Meter.
In exposure meters, photocells are used also. This is the instrument that works together with the camera in order to know the precise time of exposure of the film to have a good picture. For a picture to be of high quality. When the light intensity is high, the film exposure should be minimal and vice-versa.
This exposure meter is constructed using a photocell, series-connected battery, and a sensitive milliammeter. The amount of photoelectric current developed in the cell is in direct proportion with the amount of light intensity.
When the milliammeter deflection is less, the photoelectric current will also be minimum which indicates minimal light intensity so that exposure is maximum. In the same way, when the milliammeter deflection is more, the photoelectric current will also be more which indicates high light intensity so that exposure is minimal.
Summary of Photocell Application.
I have managed to find 22 use of photocells in real day to day applications. Which one of the 22 applications do you use? Share with me your experience working with different types of photocells in the comments section below.