Company Info
Superior Electric is located in Bristol, Ct. The company has been producing variable transformers (Powerstat) since 1938. Later they started with the production of synchronous and stepper motors, followed by a full range of drives and controls.

The brand name of these motors and drives is Slo-Syn

This page contains a part of my collection of historical Superior Electric documentation, converted to PDF. These catalogs are from 1968 to 1975. You can find a lot of very famous products, like STM1800, NCI, MNC, LNC, PNC, TRP125 and even a financial report from 1967.