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. 26, 1985
Filed:
May. 17, 1984
Haruchika Machida, Sagamihara, JP;
Sadataka Yuchi, Sagamihara, JP;
Hochiki Kabushiki Kaisha, Tokyo, JP;
Abstract
A fire alarm system having a plurality of fire detectors connected in parallel with each other to a pair of power/signal lines leading to a central signal station and adapted to respond to the signal station with a detection signal in the mode of current and controlling the signalling between the fire detectors and the signal station. The detection of a fire is accomplished by computing a difference between a steady-state current flowing through the signal lines and a detection current which are detected in an analog amounts. Each of the fire detectors is called by a simple calling clock pulse whose transmitting timing is controlled by a microcomputer of the central signal station to transmit a detection data. The generation timing of the calling clock pulses is freely selectable to effect a desired control of the fire detectors.