I am new to electronics and working on building regulated linear bench power supply 0v to 30v, 3A as my first project.

For better performance, wanted to switch between multiple tapas of ac-to-ac transformer depends on required output DC voltage. So my switching device(relay/ some other) output will feed into full bridge rectifier and then voltage and current control circuit. 

What is the best method to switch between transformer taps other than relays? Any example semantics and part numbers? 

The transformer taps 12v/24v 100va.

Thanks for the help.