1+ 2+ 3 Shaker Flashlight Modification _{By Cy Tymony}

Powering small electronics with your muscles.

You will need: Shaker flashlight, wire, small Phillips screwdriver, soldering iron, solder

How a Shaker Flashlight Works

A shaker flashlight has a bright LED, a NiCad battery, and an electrical generator made from a coil of wire and a cylindrical magnet. When you shake the flashlight, the magnet slides within the coil to charge the battery. Shaker flashlights provide about 2 to 4. 5 volts but produce a very low output current, so there will be limits on their ability to supply power to devices. Recently Walgreens stores offered one for just $5.

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1. Modify the flashlight.

Figure 1 shows the basic parts of the flashlight — the case, coil, magnet,

battery, and printed circuit board. Unscrew the lens assembly and remove the screws that secure the PC board to the case. Remove an LED lead and solder 3 wires in place (Figure 2), so you can still use the flashlight normally when you’re through powering other devices.

To power a device, connect the 2 wires attached to the flashlight’s PC board, with the correct polarity, to the device’s battery clips. When you need to use the flashlight normally, connect the LED wire and one of the PC board wires together (use color-coded wire or labels for easy identification).

2. Adapt a device to connect to flashlight. Select a device that requires 1½ to 3 volts at low current, like a small electronic LCD video game. (I’m an avid collector of the free handheld games that fast food outlets supply with kids’ meals. They require very little power if you turn off their sound option.) Wrap the bare ends of 2 wires tightly around the clips. Figure 3 shows the electronic game connected to your shaker power supply.

3. Go further.

A larger NiCad battery can be substituted for more capacity. You should be able to power other low-current devices such as a small Walkman-type AM radio, travel clock, or micro radio-control car. You might also (possibly) use the modified flashlight as an emergency cellphone power supply.

Illustrations by Timmy Kucynda

Cy Tymony ( sneakyuses.com) is a Los Angeles-based writer and is the author of Sneakier Uses for Everyday Things.

48 Make: Volume 08