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IntroductionVirtually all digital cameras in the market today are powered by batteries. Bigshot, on the other hand, is designed to be "green" and inexpensive, and comes with a manual power generator that lets it take photos without a battery.
Figure 1 shows the various components of Bigshot’s power generator. The dynamo [1], seen at the center of Figure 1, is an electric generator similar to those that power houses. When a user turns the hand crank, Bigshot's dynamo converts the mechanical energy that he or she exerts into electrical energy. In order for it to generate a large enough voltage, however, it must be spun at thousands of rotations per minute [1]. Turning the crank at such speeds is impossible, so the camera has a gearbox [2] between the crank and the dynamo instead of connecting the two directly. The gearbox spins the dynamo at very high speeds, even when the crank is rotated slowly. The electrical energy produced by the dynamo is stored in a device called a supercapacitor [3] (which works like a rechargeable battery) so that it can be used to take photos later. Each time a photo is taken, the camera consumes energy directly from the supercapacitor. Once all the energy is used up, the supercapacitor can be recharged by cranking the dynamo. Click on the play button in Figure 1 to see how the rotating hand crank drives the power generator. Use the slider to control the speed of the rotation.
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