oscillatorA device converting direct to alternating current, used, for example, in generating radio waves. Most types are based on an electronic amplifier, and small portion of the output being returned via a feedback circuit to the input, so as to make the oscillation self-sustaining. The feedback signal must have the same phase as the input; by varying the components of the feedback circuit, the frequency for which this occurs can be varied, so that the oscillator is easily "tuned." Crystal oscillators incorporate a piezoelectric crystal (see piezoelectric effect in the tuning circuit for stability; in heterodyne oscillators, the output is the beat frequency between two higher frequencies. Related category ELECTRONICS AND SEMICONDUCTORSAlso on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History |