Electronically controlled dry-disk rectifier

In spite of the practically universal use of alternating current for power generation and distribution, there exists an ever-increasing demand for direct current. To obtain direct current from the available supplies of alternating current, means of rectifying the alternating current have been developed. While many types of equipment are available, three types, each supreme in its own range, are found to be in general use for heavy-duty d-c power applications. The mercury arc has proved most efficient for the higher voltages from 250 volts on up. The intermediate range from 60 volts to 250 volts is supplied by the motor generator set. In comparatively recent years the low-voltage range from 0 to 60 volts has been taken over more and more by dry-plate rectifiers.