Almost all inexpensive commercial LED flashlights use a 4.5V power supply—three AA or AAA batteries—because white LEDs require 3.3 to 3.5V to fully turn on. Thus ...

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 ...

In this educational film, Mr. Grant explains the basics of electricity to Frank and Joan while repairing Joan's flashlight. He demonstrates how a broken wire prevents electricity from flowing, leading ...

Many of us store a flashlight around the house for use in emergency situations. Usually, regular alkaline batteries are fine for this task, as they’ll last a good few years, and you remember to swap ...