Drive and braking network for magnetic tape cassettes - provides accurate drive speed sand rapid braking using two independent spool drive motors

摘要

The drive and braking network is for use in magnetic tape decks and particularly for magnetic tape cassette decks. The transistor drive circuit and two independent reversible spool drive motors provide accurate speeds and very rapid braking. Two independent motors (2, 3) one for each cassette (1)spool are driven by a transistor amplifier which incorporates a feedback network monitoring the back e.m.f. of the motor being driven to establish an accurate running speed. When a brake switch (9) is closed a pulse is fed through a capacitance (13) into the feedback amplifier (6, 7) and simultaneously a constant current pulse (10, 11) is fed to the other motor (2). The tape is thus rapidly arrested.