What is the basic difference between relaxation oscillator and RC oscillator?

Answer 1

A nonlinear or relaxation oscillator produces a non-sinusoidal output, such as a square, sawtooth or triangle wave. And RC oscillator produces sinusoidal output.

Answer 2

The difference between an RC and LC is that the frequency - determining device in the RC oscillator is not a tank circuit. LC can operate with A or C biasing, while RC can only operate with A.

Answer 3

A feedback oscillator uses a small part of its Output Signal , to be fed back to its Input side , such that the Signal Amplitude on the Input goes on Increasing & therefore the Corresponding Output ( usually after a suitable Amplifier Section ) is also considerably Increased. This Action is also better known as Positive Feedback. To get a good stable oscillator output , the circuit has to be designed suitably limit the operation of the feedback or the output amplitude.

This effect is ( more often an undesired ) noticiable in closed / small halls where microphones & speakers which are Not properly placed , will cause a whistling or whinning sound when the speaker amplitude is too loud.

A relaxation oscillator on the other hand works in the Negative Resistance Slope ( i.e the device used has in a particular range of operation a resistance which decreases with increase in Voltage / Current ; this being opposite of majority of normal electrical/ electronic where the resistance increases with Voltage / Currrent ) The Relaxation Oscillator circuit uses this property , usually by charging a capacitor across the Active device , which periodically gets triggered after a certain threshold level , when the capacitor is discharged & the process repeats itself. Typical Devices use Gasfilled Tubes ( similar to neon bulbs ) or Semiconductor devices designed with such specific properties eg. UniJunction Transistor & Tunnel diodes.