<Li> Power distribution, see 3 wire single phase . </Li> <Li> Historically producing full - wave DC with a center - tapped transformer and two rectifiers was preferred to the full bridge rectifier when rectifier costs were higher than the extra cost of copper windings and iron laminations (a centre tap only uses half of the secondary coil per half - cycle .) They saved the cost of two diodes, and also (but less importantly) halved the voltage drop across the rectifying stage . However, now the economic case has reversed and bridge rectifiers are much more common . </Li> <Li> Phantom power can be supplied to a condenser microphone using center tap transformers . One method, called "direct center tap" uses two center tap transformers, one at the microphone body and one at the microphone preamp . Filtered DC voltage is connected to the microphone preamp center tap, and the microphone body center tap is grounded through the cable shield . The second method uses the same center tap transformer topology at the microphone body, but at the microphone preamp, a matched pair of resistors spanning the signal lines in series creates an "artificial center tap". </Li>

What is the function of center tap transformer