In this paper in addition to certain novel investigations the efficiency, power factor and voltage regulation of mercury-arc convertors are discussed and test results on a 6-kW set are given. These standard results are needed fro reference, etc. In practice many different rectifier circuits are employed, some of which operate in a complicated manner. Such circuits are avoided in the first part of this paper and the performance of one of the simplest arrangements is dealt with. Later some of the more complicated circuits are discussed
