A compensated automatic synchronizer

A relay for automatically synchronizing rotating machines has been developed which uses vacuum tubes to reduce mechanical adjustments, and which gives the closing indication at a constant time in advance of synchronism. This latter quality is shown to be required for rapid synchronizing with acceptable accuracy, in the absence of extremely accurate speed control. The theoretical requirements of such a synchronizer are derived mathematically in this paper, and a description of a relay which fulfills these requirements is given.