Bridge rectifier wiring with and without filter

#Technical Studies – Study 5

Definition

Bridge rectifier is a circuit that uses four diodes in a bridge configuration to produce full wave rectification from AC input signal.

Construction:

It uses a step down transformer, four diodes, a load resistor and an AC source.

The circuit connection is shown below.

Construction of Bridge rectifier

Operation:

When AC sinusoidal signal is applied

Bridge rectifier circuit during positive half cycle

During positive half cycle of the signal D1 and D4 conducts and the load current flows from positive to negative direction.

Bridge rectifier circuit during negative half cycle

During negative half cycle diode D3 and D2 conducts and the load current flows from positive to negative direction.

During both half cycles of the input the load current direction is same and the load voltage has the same polarity.

In output signal the negative half cycle of the input signal is shifted to positive side.

Input and output wave forms of bridge rectifier

The output is same as the full wave rectifier.

Output frequency:

As the bridge rectifier output is same as full wave rectifier, the output frequency of the bridge rectifier is same as the output of full wave rectifier.

Dc value of output:

Because the output of bridge rectifier is same as full wave rectifier the dc value is same as full wave rectifier.

Vdc= 0.636 Vp

Ripple factor:

The ripple factor for bridge rectifier is 0.482.

Efficiency:

Bridge rectifier efficiency is 81.2%

Peak inverse voltage:

Peak inverse voltage is vs max.

Advantages:

High efficiency

1.Full secondary voltage of the transformer is used

2.Fewer ripples

Disadvantages:

Circuit is complex

Bridge rectifier with filter:

The output of bridge rectifier contains both AC and DC components. The application needs pure dc. So the rectified output requires further processing. The unwanted AC component can be reduced by adding a filter to the rectifier.

Below circuit shows a bridge rectifier with capacitor filter.

Bridge rectifier circuit with capacitor filter
Bridge rectifier wave forms with filter

Please write in the comment box below if you have any questions.

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