Hawkins Electrical Guide v. 06 (of 10) / Questions, Answers, & Illustrations, A progressive course of study for engineers, electricians, students and those desiring to acquire a working knowledge of electricity and its applications

by N. Hawkins

Fig. 2,120.—General Electric 100 volt mercury arc rectifier tube. A,A, anodes; B, cathode; C, starting anode; D, tube or bulb.

Ques. In the operation of a rectifier, name an inherent feature of the mercury arc.

Ans. A reverse pressure of approximately 14 volts is produced, which remains nearly constant through changes of load, frequency, and voltage. Its effect is to decrease the commercial efficiency slightly on light loads.

Ques. What is the advantage of a rectifier set over a motor generator set?

Ans. Higher efficiency and lower first cost.

Ques. What is the capacity of a rectifier tube?

Ans. 40 to 50 amperes.

Ques. How is greater capacity obtained?

Ans. When a greater ampere capacity is required, two or more rectifier sets can be joined to one circuit.

The rectifier may be joined in series for producing an increased voltage or two tubes can be connected in series in a single set.