Simple Flashlight
This shows a very simple flashlight project with a LED and a resistor. The switch controls if the light is on or off. Build this into a small casing, and you have yourself a homebuilt flashlight.
You can use any battery voltage for this, as long as you adjust the resistor value to match.
The Circuit
The switch opens or closes the circuit, making current flow or not. The value of the resistor sets the current in the circuit. A 470-ohm resistor will give a current of around 10mA for most LEDs. If you use bright white LEDs, you might want more current and will need to use a lower resistance value.
Parts List
Battery
9V
LED
White
Resistor
470
SW1
Switch
