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. 12, 1995
Filed:
Mar. 15, 1994
Hochiki Corporation, Tokyo, JP;
Abstract
A disaster prevention monitor is disclosed in which the power consumption during a line monitoring process is reduced, and a disconnection or a short circuit of control lines can be detected by using a single switching means. A central station has a monitor command transmitter for transmitting a monitor command signal to initiate monitoring of power and control lines. A terminal or repeater station has circuitry for controlling the connection of control lines between a line monitor and power lines. During normal conditions, the control lines are not connected to the power lines, but become so connected only in response to a command from the central station. A line monitoring command causes generation of a negative voltage which is applied to line monitoring circuitry to actuate such circuitry for monitoring the status of the power and control lines.