Contactless control circuit of asynchronous electric crane mechanisms.

Abstract

A contactless control circuit of an asynchronous electric drive is considered. An asynchronous motor is powered by a reverse thyristor converter, covered by negative speed feedback. The use of a contactless relay, assembled on two triggers, allowed us to obtain mechanical characteristics that provide automatic transition from motor mode to brake switching of reversing thyristor groups depending on the polarity of the input signal, equal to the difference of the driving voltage and emf. tachogenerator. Such a system can be applied to crane lifting mechanisms that require safe descent characteristics. Ill. 3, Bible. 1.