The Change-Speed PAM Motor and Its Application in the Rubber and Plastics Industries

This paper describes a new drive tool for the rubber and plastics industries that will save money on operating and initial costs, and provide the reliable service of a squirrel-cage induction motor. The pole amplitude modulation (PAM) motor is a two-speed single-stator-winding induction motor that is ideally suited to many drives, such as mixer drives, pump and fan drives-in fact, any drive where there is an advantage to have a choice of operating speeds. The paper is divided into two main parts. Firstly, some specific applications and the advantages of using PAM motors are discussed; secondly, the theoretical and operating aspects of pole amplitude modulation are explained.