New types of D-C transformers

This paper presents 2 new types of d-c transformers using grid-controlled mercury-arc rectifiers. These transformers perform the same function on a d-c system as does the usual transformer on an a-c system. One type of d-c transformer which is discussed has a constant-current output characteristic, while the other has a constant-potential output. The theory of operation and operating characteristics are described and oscillograms taken on a small unit are shown.