Photocell

The security system has a photocell that triggers an alarm when someone enters the restricted area.

The photocell in the phone converts the voice of the speaker into an electrical signal.

A photocell is a type of electronic device that can be used to detect light.

The photocell in the calculator detects the light from the screen to turn off the device when not in use.

The photocell in the streetlight turns on automatically when it gets dark.

The photocell was a crucial component of the early television camera.

The motion sensor light uses a photocell to detect movement and turn on the light.