Need: Any circuit that generates an alternating voltage is called an oscillator. To generate ac Voltage, it takes energy from the dc source. 1. In some applications voltages of low frequency are required where as in other application voltages of higher frequency are required. 2. In industry, it is frequently necessary to heat different kind of materials. 3. Oscillators are also needed in testing laboratories.
In radio Transmitter and receiver.
It is used in the radio and mobile communications.
It is used to generate clock in digital systems.
It is used as sweep circuits in TV and CRO.