Hi,
The transformer has multiple of application in rectifier but if offers its own limitation. Few limitations of center tapped transformers are as follows:
1. Transformer Utilization Factor (TUF)
TUF of center-tapped transformers in full-wave rectifiers (0.693) is less than that of ordinary transformers in bridge rectifiers (0.812).
2. Core Saturation
Saturation of core is another drawback of this type of transformers as only one sided flow of flux is allowed which causes early core saturation as compared to ordinary transformers in which opposite directional flux cancels net effect.
3. Efficiency
It is a fact that in center-tapped transformers half of the secondary coil is used at a time, while the other half remains unused. This results as a reduction in the efficiency and therefore ordinary transformers are regarded as more efficient.
4. Cost and Size
Center-tapped transformers give half of the voltage across its secondary as output. In other words rating of a center-tapped transformer has to be twice of the desired output. Therefore center-tapped transformers are costly and occupy more space.