Question

Sketch block diagram of D.C. regulated power supply. State functions of each block.

Answer 1

Diagram : 

Functions of each block:  

1) Transformer: It Converts an AC input source to AC required output without changing frequency. The transformer is step up or step down transformer. 

2) Rectifier: It is a circuit which is used to convert AC into pulsating DC. A rectifying diode is used. 

3) Filter: It is a circuit used to convert pulsating DC into pure DC. A inductor and capacitors are used as filter 

4) Voltage regulator: An unregulated DC voltage is converted into regulated DC voltage. IC 78XX & 79XX series are used as regulator.

Answer 2

Transformer:- AC input voltage is applied to step down transformer which reduces amplitude of ac voltage to required level . 

Rectifier: Reduced ac voltage is applied to rectified which converts it into pulsating dc voltage.usually bridge wave rectifier is mostly used. 

Filter: Pulsating dc voltage is applied to filter which eliminates ac ripples from signal and convert it into pure dc. 

Types of fiter:- C fiter,L filter,LC Filter,CLC Filter. 

Regulator: The combination transformer ,rectifier and filter makes unregulated power supply.which gives unregulated power supply to convert it into regulated an regulating element is used which keeps output voltage constant. 

Answer 3

There are four basic blocks of a d.c. regulated power supply. They are 1) Step down transformer 2) Rectifier 3) Filter 4) Voltage Regulator. 

Functions of each block are as follows : 

Step down transformer : Reduces 230 volts 50Hz ac voltage to required ac voltage level. 

Rectifier : Rectifier converts ac voltage to unidirectional pulsating voltage. It may be a halfwave rectifier, a full-wave rectifier using a transformer with centre-tapped secondary winding or a bridge rectifier. 

Filter : Filter is a circuit used to remove fluctuations (ripple or ac) present in rectifier output. 

Voltage Regulator : Voltage regulator is a circuit which provides constant dc output voltage irrespective of changes in load current or changes in input voltage.