Abstract: A system for preventing improper tape feed in a cassette tape player uses pulse width measurements from the take-up reel output signal to sense normal or aberrant tape feeding conditions. The pulse width of the output signal is compared with a predetermined range of pulse widths associated with normal tape operation. The range is variable as a function of the rotational frequency of the take-up reel and is updated periodically to reflect changes in the diameter of the take-up reel as the tape plays. If the pulse width of the output signal falls outside of the predetermined range, it denotes an aberrant tape feeding condition.

Abstract: A plurality of sensing means are actuated by the rotation of a take-up reel in a reel-to-reel type tape deck wherein the frequency of activation of switches determines whether or not drive power should be continued to the tape deck drive mechanism. Monostable multivibrator circuits are employed to respond to the bi-level signals output from the switch means and provide respective enabling signals to a logic circuit so that when either one of the multivibrators circuits provides an output in response to the rotating switch means, the logic circuit will continue to allow driving power to be supplied to the tape deck.

Abstract: The invention provides sensing switches for indicating proper rotation of a take-up reel in a tape recorder-player and for sensing reverse rotation of the take-up reel and provides a logic circuit for stopping the drive of the take up reel when the tape is not properly fed or when the take-up reel rotates in a reverse direction.