(i) Full wave rectifier : It is a device which produces a unidirectional, pulsating output current for both halves of the ac input voltage i.e., it converts ac into pulsating dc.
(ii) Amplifier: An amplifier is a device used for increasing the voltage, current and pow er of an alternating form by supplying energy from an external source. The amplitude of the output signal is greater than the amplitude the input signal.
(iii) Oscillator : It may be defined as an electronic device which converts energy from a dc source into electrical oscillations of constant amplitude and frequency. For this conversion, an oscillatory circuit like L-C circuit is usually required.
