Definition of Photocell

A photocell or photoelectric cell, is a type of electronic component that senses light levels and can automatically switch on or off a light source based on the amount of light detected.

Have you ever wondered how street lights automatically go on at dusk? It’s thanks to photocells. Think of photocells as a controlled switch that responds to light or photons.

Photocells are typically used for:

  • Outdoor lighting: Automatically turn lights on at dusk and turn them off at dawn for streetlights and solar lights like the Nario LED Solar Piling Light, reducing energy costs and light pollution.
  • Security lighting: Used together with motion sensors can trigger security lights when motion is detected and turn them off during the day to conserve energy.
  • Indoor lighting: Automatically turn lights on when natural light levels are low indoors, for example night lights or automatic courtesy lights
  • Signage: Used to automatically turn on illuminated signs at dusk and turn them off at dawn, extending the life of the sign and reducing energy costs

diagram of a photocell construction and function

Photocells are necessary to any lighting system that needs an automated on/off switch. To make sure they function well, always check that the voltage rating on the photocell matches the voltage of the electrical circuit.

However, it’s important to keep in mind that they frequently fail due to dirt, moisture buildup and lens discoloration. They should therefore be checked often to ensure continuous function.

Example of Photocell in a Sentence

"The photocell installed in the outdoor lighting system automatically turns on the lights at dusk and turns them off at dawn."

Synonyms: photoelectric cell

Related Terms for Photocell