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:
Dec. 25, 1984
Filed:
Apr. 29, 1983
Dilip T Singhi, Skokie, IL (US);
Rauland-Borg Corporation, Chicago, IL (US);
Abstract
A master/slave clock system including a slave clock configured for inexpensive and reliable control from the master. Each slave clock has an unregulated d-c supply adapted to be supplied with a-c power from the master clock. Threshold switching means in each slave clock is coupled across the d-c supply to sense an abnormally low d-c voltage level intentionally created by lowering the a-c supply level from the master. The threshold switching means switches the clock from the normal operating mode to the set mode where time is incremented at a predetermined rate for a duration controlled by the master clock in order to controllably set all slave clocks in the system to the correct time of day. The system conveniently allows all slaves to be reset to the same time when time is reset at the master, provides for automatic recovery after power failures, and provides a convenient means for automatically resynchronizing all slave clocks twice a day.