JPS5481799A - Conduction test circuit of fire alarm - Google Patents

Conduction test circuit of fire alarm

Info

Publication number
JPS5481799A
JPS5481799A JP15008377A JP15008377A JPS5481799A JP S5481799 A JPS5481799 A JP S5481799A JP 15008377 A JP15008377 A JP 15008377A JP 15008377 A JP15008377 A JP 15008377A JP S5481799 A JPS5481799 A JP S5481799A
Authority
JP
Japan
Prior art keywords
voltage
circuit
current
break
constant
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP15008377A
Other languages
Japanese (ja)
Inventor
Masatoshi Maeda
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Electric Works Co Ltd
Original Assignee
Matsushita Electric Works Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Works Ltd filed Critical Matsushita Electric Works Ltd
Priority to JP15008377A priority Critical patent/JPS5481799A/en
Publication of JPS5481799A publication Critical patent/JPS5481799A/en
Pending legal-status Critical Current

Links

Landscapes

  • Fire Alarms (AREA)
  • Fire-Detection Mechanisms (AREA)

Abstract

PURPOSE: To make it possible to detect accurately the breaking of a fire alarm circuit without providing specially a testing power supply, by attaching a constant- current circuit.
CONSTITUTION: Constant-current circuit CC is provided which is connected to power supply E1 via normally break side NO of alternation switch S1, and its constant-current output is flowed to the parallel circuit composed of fire detector S3 and resistance Re, thereby detecting its output terminal voltage. With switch S1 is switched to NO at this time, current I1 flows from power supply E1 to the parallel circuit via circuit CC and through the setting of the resistance value, voltage drop ReI1 of resistance Re becomes lower than voltage Vc of detector S. Then, when the circuit operates normally, the voltage between L and C indicates ReI1; since current I1 flows to detector s3 in case of a break at point A, and the voltage between L and C becomes higher than voltage Vc and when a break occurs before the parallel circuit, it indicates the maximum voltage of circuit CC. It is therefore detected accurately by measuring the output voltage whether a break is occurring or not.
COPYRIGHT: (C)1979,JPO&Japio
JP15008377A 1977-12-13 1977-12-13 Conduction test circuit of fire alarm Pending JPS5481799A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP15008377A JPS5481799A (en) 1977-12-13 1977-12-13 Conduction test circuit of fire alarm

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP15008377A JPS5481799A (en) 1977-12-13 1977-12-13 Conduction test circuit of fire alarm

Publications (1)

Publication Number Publication Date
JPS5481799A true JPS5481799A (en) 1979-06-29

Family

ID=15489132

Family Applications (1)

Application Number Title Priority Date Filing Date
JP15008377A Pending JPS5481799A (en) 1977-12-13 1977-12-13 Conduction test circuit of fire alarm

Country Status (1)

Country Link
JP (1) JPS5481799A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51129197A (en) * 1975-05-02 1976-11-10 Matsushita Electric Works Ltd Continuity test circuit of fire alarm

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS51129197A (en) * 1975-05-02 1976-11-10 Matsushita Electric Works Ltd Continuity test circuit of fire alarm

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