Speed control regulation for magnetic tape recorder - has regulator circuit that compares pulse frequency with video signal frequency value and feeds control data to tape drive motors

摘要

A precision control system is used for accurate speed control of magnetic tape feed in a tape recorder. The regulator circuit (10) requires an accurate input of the actual speed of the tape. In one method, a frequency proportional to speed may be generated based upon known spool diameter and tape thickness together with counting of spool revolutions (13).S Alternatively a tachometer (19) may be used to generate a pulse sequence that can be converted into a frequency using a spool winding diameter measurement. A further method adopts a frequency divider controlled by the diameter measurement (15,16). A braking system (21) is used to maintain correct tension.