Half-Wave rectifier: The rectifier that converts only one half of ac into dc is called half-wave rectifier.
Circuit diagram:
Working: The ac input signal to be rectified is fed to the primary coil of the transformer. The secondary coil is connected to the junction diode in series with a load resistance RL.
For positive half cycle of ac, point A of secondary coil is positive and point B is at zero potential. Since A is connected to p-region of the junction diode, the junction diode is forward biased. Thus, the junction diode conducts. The output voltage which varies in accordance with input half cycle is obtained across RL.
For negative half cycle of ac, point A is negative and point B is at zero potential. So the junction diode is reverse biased. Hence the junction diode does not conduct, and therefore, no output across load resistance is obtained. The variation of output corresponding to input is as shown below: