This dark activated switch can trigger a relay to operate an AC lamp at Sunset. The lamp remains on till morning and then turns off. This eliminates the need of switching the Porch lamp or Backyard ...

This light activated remote switch circuit could be operated using a flashlight beam and could eb used for toggling a specified load from a distance using an external light source such as a flashlight ...

Transistors, the tiny switches that flip on and off inside computer chips, have long been the domain of electricity. But scientists are beginning to develop chip components that run on light. Last ...