Engineers had learned that a resistor, which restricts the flow of electrical current, is best made of certain materials and a capacitor, which stores electrical charge, of others.

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The capacitor will power electrical components such as the air conditioning and stereo, which are normally powered by an alternator connected to the engine.

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The expert said a degraded capacitor, a circuitry component used in various electrical appliances, was the likely cause of the fire.

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By storing excess electrical energy that is generated by the dynamo in a capacitor, and getting the spring to unwind only when the capacitor charge falls below a certain threshold, it has proved possible to extend the playing time of the second-generation radio to about an hour.

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