Q. Give the classification of oscillators. Discuss the frequency stability of oscillators.

Oscillators are classified in the following different ways.

1. According to the waveforms generated:

· Sinusoidal oscillator: This oscillator generates sinusoidal voltage or currents.

· Relaxation oscillator: This oscillator generates voltages or currents, which vary abruptly one or more times in a cycle of oscillation.

2. According to the fundamental mechanisms involved:

· Negative resistance oscillator: It uses negative resistance of the amplifying device to neutralize the positive resistance of the oscillator.

· Feedback oscillator: It uses positive feedback in the feedback amplifier to satisfy the Barkhausen criterion.