The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 06, 1984
Filed:
Oct. 27, 1982
David R Rodal, Palo Alto, CA (US);
Ampex Corporation, Redwood City, CA (US);
Abstract
A power fail circuit provides protection for tape such as used in the tape transport apparatus of a video recorder in the event of a failure of the external power supply. The tape transport apparatus includes as a feature the provision of an electrical error signal used to govern drive motors to maintain substantially constant tape tension when the system is operating normally. After power failure occurs, the power fail circuit continues to respond to the error signal by coupling current from the drive motors to provide dynamic braking. Further, current taken from the drive motors selectively is coupled to an energy storage device operatively associated with the system power supply, to provide augmenting energy from the kinetic energy of the motors for continued control of the power fail circuit as the drive motors are caused to decelerate under control to stop.