Rectifiers an introduction

What is a Rectifier

Rectifier is an electronic device , which converts alternating current supply into direct current supply with help of diode .

Diode is a semiconductor device. It is a unidirectional device conduct electricity in one direction. Alternating supply is changing its magnitude and direction with particular time interval, but DC always flow in steady state condition (neither its direction or magnitude changes).

Need of rectifiers

In modern era, many electronic devices are being used. All devices have number of electronics components such diodes, transistors, Integrated circuits. These electronic devices required DC voltage for their operation. Everyone knows that , DC supply can be generated from small size of dry cells. But it can provide limited amount and power ( VI). There are many large applications used in industry like electro plating, operation of locomotives is requires huge amount of DC power.

To satisfy those power requirement AC voltage is converted using suitable rating of rectifiers. It also need to be noted that , using cells and batteries to satisfy their power requirement , large size of setup is required. Further its maintenance and operation cost also increases. So it is not economical to store converted DC supply into batteries for larger application. AC supply always available nowadays. Whenever DC supply required, we can convert it using rectifiers.

Another big challenge in converted DC supply cannot be used directly. Because they are not in pure DC like generated in DC source such batteries and cells. Hence to smoothening DC output voltage received from rectifier passed through appropriate filter circuit.

However, Rectifiers are most preferable devices to fulfil DC supply demand

Types of Rectifiers

Rectifier can be classified with various specification like input supply, pattern of wave conversion, its controlling type. Please refer below fig.

According to Input Supply

1. Single phase rectifier
2. Three phase rectifier

According to wave conversion

1. Half wave rectifier
2. Full wave (Three phase) rectifier
3. Centre tapped full wave (single phase) rectifier
4. Bridge Rectifier

According to control method

1. Uncontrolled Rectifier
2. Half controlled rectifier
3. Fully controlled rectifier

Application of Rectifiers

1. Electroplating industries
2. Battery charging equipments in substation and battery manufacturing industries
3. DC motor drives
4. In HVDC transmission system
5. Electro locomotive services
6. Commercial , home electronics appliances