Patent · US Expired

Environmental abnormality alarm apparatus

US4924417A · kind A · utility

23Cited by
14References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 21, 1988
Grant dateMay 8, 1990
Priority date
Expiry dateMar 21, 2008

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG08B26/002
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

An enviromental abnormality alarm apparatus includes a plurality of terminals connected to a transmission line and a central processing unit. A specific address is assigned to each of the terminals. The central processing unit sequentially circularly accesses the addresses of the terminals and receives a signal corresponding to a physical change such as a fire, gas leakage, or burglary supplied from each terminal. Each terminal includes an alarm determination reference setting unit, a comparator for comparing the physical change signal with an alarm determination reference value, and an output unit for supplying a comparison result from the comparator. The alarm determination reference value of the alarm determination reference setting unit is set by transmitting and receiving data to and from the central processing unit.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.