Polyphase reaction synchronous motors

摘要: THE reaction synchronous motor in its present form (salient-pole rotor without field coils) is one of the oldest types electric motors, antedating induction by many years. At first it was used only connection with instruments, such as oscillograph etc.; later simplicity and exactness keeping step made standard driving for rectifying devices are charging low-voltage batteries, supplying high-tension unidirectional current x-ray precipitation apparatus etc., where power may amount to several h. p. It is, however, safe say that limit output type practically reached; low weight efficiency poor performance inadmissible motors larger seem justify general opinion inherently inferior other a-c. motors.