DC POWER SUPPLY TUTORIAL AND BLOCK DIAGRAM

INTRODUCTION TO DC POWER SUPPLY

Electrical energy is generated, transmitted and distributed in the form of AC (alternating Current). Commonly most of our home appliances works in AC.
Unfortunately, some of them works only in dc (Direct Current). In this situation we have to use a DC POWER SUPPLY.
DC Power supply is a device which is capable of delivering direct Current by feeding in the alternating Current.

ie; The input to the dc power supply is an alternating Current and the output will be direct Current. That is a rectification occurs inside the power supply.

BASIC BUILDING BLOCK OF DC POWER SUPPLY

1.TRANSFORMER

2. RECTIFIER

3. FILTER

4. VOLTAGE REGULATOR

EXPLANATION OF DC POWER SOURCE

TRANSFORMER

Transformer works on the basis of ELECTROMAGNETIC INDUCTION and they are mainly classified into two

• STEP UP TRANSFORMER
  
• STEP DOWN TRANSFORMER
  

Step up transformer up convert the input voltage where step down transformer down converts. For a DC Power Source we have to use step down transformers, to covert the high voltage AC supply to low voltage DC.

RECTIFIER

Rectifiers are used to convert the sinusoidal AC voltage to non-sinusoidal pulsating DC. The main component used in Rectifiers are diodes due to its switching action. They will conduct Current only in one direction, hence the voltage. So we can use them on rectifiers to make the alternating Current unidirectional.
Rectifiers are classified into Three :-

• HALF WAVE RECTIFIERS
  
• FULL WAVE RECTIFIERS
  
• BRIDGE RECTIFIERS 

FILTERS

Filters are used to eliminate or filter-out the unwanted ripples from the rectified output. Filters play an important role in dc Power supplies, they make the pulsating dc steady.

VOLTAGE REGULATOR

Voltage Regulators are used to regulate the output voltage over load. They make the Voltage unvaried with load connected to it. This will eliminates the remaining ripples from the filter output. The output from Voltage Regulator may be the required DC. Voltage Regulators includes some safety measures such as Current Limiting, short circuit etc......