Whenever I take apart something, such as radio-control car, the motor is populated with capcitors. About three of 0.01 or 0.1uF ceramic capcitors are attach to the eletric motor. Does anyone know of this reasoning of attaching these capcitors?
audioguru2
- Apr 6, 2004
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Quantum,
A simple DC electric motor has brushes to contact the rotating armature, which causes radio-interference. The capacitors filter the interference so that it is not radiated to the receiver, and so that power supply interference is also reduced.
A simple DC electric motor has brushes to contact the rotating armature, which causes radio-interference. The capacitors filter the interference so that it is not radiated to the receiver, and so that power supply interference is also reduced.
Audioguru, I see your point, however I have heard about capcitors that filter, such as in a rectifier (perhaps ;D), and also a tuning a radio with a variable capcitor. I know that if a capcitor is attach to an AC outlet, the capcitor charges and discharges rapidly because of the alternating current. Does this concept work with filtering radio interference or is there an entirely different concept?
audioguru2
- Apr 6, 2004
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Quantum,
Since a capacitor takes on, holds and releases a charge, the voltage across it cannot change quickly, thererfore it filters-out high frequencies. Usually a higher capacitor value has better filtering, except at radio/TV frequencies where a large capacitor is actually an inductor due to the way that it is made in a coil.
Since a capacitor takes on, holds and releases a charge, the voltage across it cannot change quickly, thererfore it filters-out high frequencies. Usually a higher capacitor value has better filtering, except at radio/TV frequencies where a large capacitor is actually an inductor due to the way that it is made in a coil.
