A flashlight ("torch" outside North America) is a portable hand-held electric light. Usually, the source of the light is an incandescent light bulb or light-emitting diode (LED).
Now I am going to instruct how to make a LED flashlight with less number of components.
Step 1: Components Required
Step 2: Placing Components
Apply a piece of double sided tape at side of the battery and top of the snap.
Place switch on the double sided tape which was on side of the battery.
Place SMD LED on the double sided tape which was on snap.
Step 3: Circuiting
Solder negative terminal of the snap to negative terminal of led.
Solder positive terminal of the snap to top pin (pin 1) of switch.
Solder a wire from middle pin (pin 2 ) of switch to positive terminal of the LED.
Here the construction of flashlight is completed.
Note : I recommend you to use 9v rechargeable battery because normal battery discharges very fast or you can use any 12V rechargeable battery source.When you are using 12V source ,there is a need to add a heat sink to the LED.