Regulation of tape recorder motor to give constant tape speed - has photoelectric spool speed sensing to generate control of motor

摘要

A speed control system for a magnetic tape cassette recorder utilises photoelectric sensing to maintain a constant tape speed. The winding spool capstans carry two signal generating discs (2A, 3A) that are sensed by non contact photoelectric sensors (8) to produce signals proportional to speed. The signals are processed through a control stage (7) to generate a command to vary the speed of the motor (5) to maintain a constant tape speed, as the diameter of the tape spools change.