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Explore the Challenges

The Challenge: Generate electricity



Generators in Cars and Bicycles

Cars need a direct-current supply to operate the ignition, lights, windshield wipers, etc. This is generated by an alternator which is mechanically coupled to the engine. A device called a rectifier is used to convert the alternating current output to direct current. A regulator also has to be fitted to control the current, so that the alternator's output voltage continues to match the voltage of the vehicle's battery as the engine speed changes.

A dynamo on a bicycle, that produces electricity as you cycle, is another example of a generator. Its basic design is just the same as the home-made generator described above.

a bicycle dynamo
a bicycle dynamo