The main difference between a Center Tapped and Bridge Rectifier is that one uses center tapped transformer while another do not require a center tapped transformer. Both these types are full wave rectifiers but their method of converting AC input into DC is different by employing different numbers of diodes.
In center tapped full wave rectifier, two diodes are used whereas four diodes are used in bridge rectifiers. Before diving into the differences between the center tapped full wave and bridge rectifiers, it is advised to first read the working principle and circuit diagram of these two types of rectifiers. You can read them here, Center Tapped Full wave Rectifier and Bridge Rectifier.
For recapping the working of both types of rectifiers, their circuit diagram is shown below.
The size of transformer required for producing same DC output is less in bridge rectifier when compared with center tapped full wave rectifier. You may think how?
As we know that the average value of DC output current for full wave rectifier is 0.636 times of the peak value of current i.e. 0.636Im. But the current Im = (Vm / R)
In case of center taped rectifier, this current Im is half of this current for bridge rectifier as in bridge rectifier full supply voltage is causing this current to flow. Thus the size of transformer required in bridge rectifier will be less. This is also evident form Transformer Utilization Factor, TUF. The TUF for center tapped and bridge rectifiers are 0.672 & 0.810 respectively.
Some of the major differences between a center tapped full wave and a bridge rectifiers are tabulated below.
|Center Tapped Full Wave Rectifier
|A center tapped transformer is required.
|No center tapped transformer is required in bridge rectifier.
|The peak inverse voltage (PIV) of diode in center tapped full wave rectifier is twice the transformer secondary terminal voltage.
|PIV of diode is equal to the transformer secondary voltage. Thus this type of rectifier can be used for high voltage application.
|Two numbers of diodes are required.
|Four diodes are required for bridge rectifier.
|The transformer utilization factor (TUF) is equal to 0.672.
|The TUF is equal to 0.810 for bridge rectifier.
|The transformer size i.e. kVA rating required for center tapped rectifier is more.
|Transformer size requirement is less.
|A bridge rectifier using four diodes is more economical when compared with center tapped rectifier.