an electronic device for producing a signal voltage

an oscillator that produces electrical oscillations at a frequency determined by the physical characteristics of a piezoelectric quartz crystal

an oscillator whose output heterodynes with the incoming radio signal to produce sum and difference tones

an electronic oscillator circuit in which the oscillation frequency is determined by a tuned circuit consisting of capacitors and inductors, that is, an LC oscillator.

a non-conservative oscillator with non-linear damping.