What is a photocell sensor switch.


An alternative gadget to use to light up part of your house’s compound automatically at night is the photo cell sensor or sometimes called a photocell switch. Some simply calls them photocell. It is more convenient than the regular time switch.

The disadvantage of using a time switch.

A time switch must have continuous supply of electricity for it to stay on time because the timing device built into these switches runs on current just like an electrical clock. If there is a black out of if the electrical supply is accidentally cut off, the time switch will stop functioning. When supply is resumed, you have to reset the time again.

In recent years though there have been an improvement in some brands where there is a spring ed clockwork like those found in grandfather’s clock built in so even if there is no current supply, the timer will still run.

The advantage of a photo sensor switch.

The photocell sensor depends entirely on sunlight to work. There is a thin strip of solar sensitive cell that acts like a normal switch terminal. When there is the slightest sunlight, the cell will expand and disconnects the 2 terminals. When there is no sunlight, it contracts and the 2 terminals will be automatically closed thereby making the circuit.

The cell is extremely sensitive to light so it must be installed somewhere where the rays of the lights don’t shine directly on the sensor switch. This will render the photocell ineffective because once the light comes on, the cells will expand and switch off the lights automatically. You will have a light that keeps switching on and off by itself. The best place is to install it somewhere where it can get the sun’s ray but not rays from the light. A good place would be right behind the lights that is controlled by the sensor.

Most street lights these days are controlled by these photocell sensors. That’s the reason you see street lights lighting by itself up on a dark and cloudy day.