5. What kind of rectifiers do brake motors have?

Two variants of rectifiers are generally used in brake motors. These are called bridge rectifiers and half-wave rectifiers.
The bridge rectifiers are generally used in motors up to size 112 and are operated at 230V.
The half-wave rectifiers are usually used from motor size 132 and are controlled with 400 volts.

Bridge rectifier

Half-wave rectifier with switching contact