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:
Aug. 14, 1984
Filed:
Feb. 03, 1983
Rainer Fey, Schweinfurt, DE;
Fichtel & Sachs AG, Schweinfurt, DE;
Abstract
The central locking system adapted especially to motor vehicles comprises a plurality of electric locking drives and a time control circuit triggerable by at least one control switch in switching over from a first switch position to a second switch position. The time control circuit switches on the locking drives for a predetermined time duration in a predetermined drive direction. A switch signal generator controlled by the control switch generates a first two-level control signal the control levels of which represent the switch positions of the control switch. The switch signal generator in the switching over of the control switch from the first switch position into the second switch position triggers a ramp signal generator which delivers a ramp signal varying in time with constant direction from a predetermined initial level. A comparator, especially a differential amplifier or an operational amplifier, compares the level of the ramp signal with the constant reference signal level of a reference signal generator and generates a second two-level control signal, the control level of which represents the sign of the level difference of the ramp signal and the reference signal. A control stage switches on the locking drives in the predetermined drive direction as long as the first control signal occurs with the control level representing the second switch position of the control switch and at the same time the second control signal occurs with the control level resulting for the predetermined initial level of the ramp signal, the control stage furthermore switching off the locking drives for the predetermined drive direction.