Line-type heat sensing fire detector with terminal capacitor

Abstract

A line-type heat sensing fire detector with a terminal capacitor comprises a line-type temperature sensor element as well as a converter box and a terminal capacitor respectively connected with the two ends of the line-type temperature sensor element; wherein the line-type temperature sensor element comprises two detecting conductors and an NTC property barrier layer parallelly arranged between the two detecting conductors; and the converter box comprises a capacitance monitor unit. The line-type heat sensing fire detector with the terminal capacitor provided by the invention not only can eliminate the increased difficulty of measurement of the fire detector in the prior art caused by the terminal resistance, but also can use the capacitance measurement unit and a voltage monitor unit or a resistance monitor unit to alternatively monitor the line-type temperature sensor element, thus resolving the problem that the open circuit fault can not be judged caused by that the terminal resistance is replaced by the terminal capacitor, therefore the fire detector can be ensured to alarm normally and reliably.

Description

technical field [0001] The invention belongs to the technical field of fire protection, in particular to a linear temperature-sensitive fire detector. Background technique [0002] Linear temperature-sensitive fire detectors are widely used fire detectors, among which parallel NTC linear temperature-sensitive fire detectors are currently commonly used. figure 1 It is a structural schematic diagram of a traditional parallel NTC linear temperature-sensitive fire detector. Such as figure 1 As shown, this parallel NTC type linear temperature-sensing fire detector includes a linear temperature sensing element 1 and one end connected to the linear temperature sensing element 1, and a resistance monitoring unit 7 is installed inside, so it can detect the resistance value of the entire loop in real time , can carry out data processing at the same time, and output the conversion box 2 of alarm signal when the alarm parameter of the whole circuit exceeds the alarm threshold; wherein...

AI Technical Summary

Problems solved by technology

However, the above-mentioned traditional linear temperature-sensitive fire detector has the following problems: the described conversion box 2 cannot monitor the open circuit or open circuit fault of the linear temperature-sensitive fire detector

The detector judges whether there is an open-circuit fault by measuring the continuity of the AC circuit composed of the detection conductor 13 and the terminal capacitance 12, but this method is not feasible, because even if the terminal capacitance 12 is removed, the two detection There is still a large line-to-line capacitance between the conductors 13, so the AC circuit for judging the open circuit fault is still conducting

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