Patent Number: 6,305,628

Title: Controlled tape stopping with feed forward during power loss

Abstract: A reel-to-reel tape system stops movement of the tape during a power losssituation without overrun by one of the tape reels and without causingundue stress upon the tape itself. If rotational momentum of the supplyreel is sensed to be disproportionately larger than the momentum of thetake-up reel, supply motor back emf for dynamically braking the supplyreel is applied while also driving the take-up reel in the direction ofrotation in which it operated when the power source was discontinued. Anappropriate amount of tension is maintained on the tape until the tapemotion has come to a complete stop. A capacitor large enough to supply thepower needed to provide current to the power bridge of the motor driversis provided. The capacitor is charged upon power up of the drive and isnot tapped unless and until the normal supply voltage of the motor driversis turned off. The take-up reel motor is provided with optimum current totake up the loose tape that otherwise would be produced in the tape pathand around the reels, thus preventing a hazardous situation.

Inventors: Thompson; Mark R. (Fountain Valley, CA), Redhead; Kempton W. (Huntington Beach, CA)

Assignee:

International Classification:

Expiration Date: 10/23/2013