The Chinatown shopper's guide to:
Shake Flashlights!
Okay, if you are here, you probably have one of those flashlights. Or, you're here because you want to
waste your time (the whole site is for momentary amusement). Now, this tutorial tells you how to tell if it's fake
or not. Most of the time it's fake.
The definition of a "real" shake flashlight:
  1. It produces electricity using a coil and magnet.
  2. It has a method of storing the generated electricity.
  3. It has a light.

1. Overview
The picture below outlines the flashlight's design. The part that makes it a "shake" flashlight is the  magnet
and coil. As you shake the flashlight, the magnet moves up and down in the tube, and through the coil.
These flashlights are sometimes called "Faraday lights" because some guy called Fraday figured out that a
magnet made electricity when it passed wire. When the magnet goes through the coil, it generates a brief
moment of electricity. It does not generate electricity while the magnet is sitting over the coil motionless.

Through two little wires, the elecricity flows to the circuit board. Because the polarity changes per direction of
the magnet, the electricity goes through a
diode bridge. This way, the electricity is the same polarity
(negative or positive) no matter what. Nerds may know that a diode bridge turns AC into DC current.

After this, it charges a small capacitor or battery, were it is stored until the light is switched on. Without the
battery, the flashlight would really be a
flash light, because it would only light when the magnet passes the
coil. Plus you couldn't aim it right. The battery acts like a shock absorber to smooth out the light.

When you switch it on, the stored electricity lights up an L.E.D. Light bulbs are generally not used because
they cannot make enough light from such a small electrical source. Sometimes, however, the electricity goes
through a resistor, which actually lowers the current. I suppose one could bypass the resistor and get a
brighter light.
I love gloating: I drew this myself. I'm just too lazy to correct the problem where the lens-side "bumper"
should point to the other black thing in front of the magnet.

waterproof, and therefore real, flashlight.
waterproof, and therefore real, flashlight.

If you have a switch, be sure to line up the metal plates on the circuit board with the switch.


First page