CHARACTERISTICS AND APPLICATIONS OF BRIDGE RECTIFIER


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                         BRIDGE RECTIFIER

A bridge rectifier converts alternating current to direct current so that if we need to convert AC input to DC output we can use this. Bridge rectifier can be created by using four or more diodes. Bridge rectifiers are widely used in power supplies that supply DC power to electronic devices. A proper bridge rectifier is selected according to the load current requirements a bridge rectifier provides full wave rectification from a two wire AC input. The main advantage of bridge rectifier is that it does not require a special center tapped transformer and by that its size and coast is reduced we can see a lot of rectifiers in many electronic devices or in components but the only center tapped full wave rectifier and bridge rectifier efficiently converts AC (alternating current) into DC (direct current)

BRIDGE RECTIFIER OPERATION

A single phase bridge rectifier with four diodes and this will be connected across the load

With the help of this diagram, we can understand the rectifier operation during the +ve half cycle D1 & D3 is forward biased and D2 & D4 reverse biased when the voltage is more than the threshold level of the diodes D1 and D3 will conduct and the load current will start to flow. And in the –ve half cycle D1 & D3 reverse biased and D2 & D4 forward biased and the load current will start to flow when D2 & D4 will conduct thus by using a bridge rectifier we could convert AC current to DC. In this rectifier we use an ordinary transformer in place of a center tapped transformer which makes it more efficient

TYPES OF BRIDGE RECTIFIERS

Bridge rectifier is classified into several types based on the factors like power supply, controlling capability, diode types

SINGLE PHASE AND THREE PHASE BRIDGE RECTIFIER

In this case, the single-phase uses four diodes to convert AC to DC while in three phases it will use six diodes these can be again classified into controlled or uncontrolled depending or circuit components like diodes or thyristors
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UNCONTROLLED BRIDGE RECTIFIER

This type of rectifiers are used in constant or fixed power supplies because the diodes only allow power in one direction and it doesn’t allow the power to vary according to the load requirement.

CONTROLLED BRIDGE RECTIFIER

In this kind of rectifier instead of using uncontrolled diodes, they use controlled solid state devices like SCR’s, MOSFET’s, IGBT’s are used to vary power according to different voltages. Thus output power of the load can be changed by triggering this device at various instants

CHARACTERISTICS OF BRIDGE RECTIFIER

PEAK INVERSE VOLTAGE

In reverse bias condition, the maximum amount of voltage a diode can withstand is called peak inverse voltage

Peak inverse voltage of bridge rectifier is PIV = V Smax

RIPPLE FACTOR

It is used to measure the smoothness of the DC signal if the signal has very less amount of ripples it is considered as smooth DC signal if the output of the DC signals have high ripples is considered as high pulsating DC signals

Ripple factor for a bridge rectifier is
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ADVANTAGES AND APPLICATIONS OF BRIDGE RECTIFIER

  • The rectifier efficiency of full wave rectifier is double as that of the half wave
  • Higher output power and voltage
  • No center tapping is required so we can use a simple transformer
  • Smaller size and cheap
  • Low ripples in the output DC signal
  • High rectifier efficiency
  • Low power loss
  • Conversion of AC to DC