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:
Sep. 03, 1991
Filed:
Jun. 06, 1989
Gene C Berrier, Fort Worth, TX (US);
Wolf S Landmann, Fair Lawn, NJ (US);
Benz Companies, Inc., Fort Worth, TX (US);
Abstract
The two wire device tests the continuity of conductors in a monitoring circuit having an open circuited apparatus. The device has a switch which is controlled by a sequencer and a clock. Upon the application of power, the device is energized if the continuity of the conductors is present. The clock provides a train of pulses that alternately opens and closes the switch. When the switch is closed, continuity across the conductors is provided to illuminate an indicator lamp. When the switch is open, a power storage unit charges from the monitoring circuit power supply. The power storage unit provides operating power to the sequencer and the clock. The output of the clock has a long duty cycle so that the time when the switch is open is very brief, thus causing the lamp to be perceived by a human as unaffected. The sequencer counts the number of oscillations produced by the clock and when a predetermined number has occurred, turns off the clock and leaves the switch open. In another aspect, the circuit has parallel branches with a device on each branch. The devices communicate with each other on the conductors to determine if continuity exists in each branch before illuminating the lamp.