JPH0227298U

JPH0227298U -

Info

Publication number: JPH0227298U
Application number: JP10238488U
Authority: JP
Priority date: 1988-08-03
Filing date: 1988-08-03
Publication date: 1990-02-22
Anticipated expiration: 2003-08-03
Also published as: JPH082798Y2

Description

[Brief explanation of drawings]

第１図はこの考案の一実施例を示す回路図、第
２図は、第１図の実施例におけるバイパス回路の
詳細図、第３図はこの考案の他の実施例を示す回
路図、第４図は、第３図の実施例における電圧―
電流変換回路の詳細図、第５図ａ，ｂ，ｃはこの
考案のガス検知部を防爆型とした実施例の側断面
図および第５図ａのＸ―Ｘ線による断面図および
Ｙ―Ｙ線による断面図、第６図ａ，ｂは、第５図
中のプリント基板部分の詳細を示す平面図および
側面図、第７図は従来のガス警報器の一例を示す
回路図である。図中、１０はガス検知部、１１はガスセンサ、
１２は補償素子、１３，１４は抵抗器、１５は取
付板、１６はプリント基板、１７は金網、２０は
指示警報部、２１は電源回路、２２は警報回路、
３０は線路、３１は信号線、４０はバイパス回路
、４１〜４４は抵抗器、４５は定電圧ダイオード
、４６は比較器、４７はトランジスタ、５０は電
圧―電流変換回路、５１，５２は比較器、５３は
トランジスタ、５４〜５７は抵抗器、６０はガス
検知部、６１はセンサケース、６２はフレームア
レスタ、６３，６４はセンサガイド、６５は電気
室蓋、６６はパツキン、６７は樹脂固着部、は
センサ室、は電気室である。 Fig. 1 is a circuit diagram showing one embodiment of this invention, Fig. 2 is a detailed diagram of a bypass circuit in the embodiment of Fig. 1, and Fig. 3 is a circuit diagram showing another embodiment of this invention. Figure 4 shows the voltage in the embodiment of Figure 3.
Detailed diagrams of the current conversion circuit, Figures 5a, b, and c are side sectional views of an embodiment in which the gas detection section of this invention is explosion-proof, and sectional views taken along line X--X in Figure 5a and Y--Y. 6a and 6b are a plan view and side view showing details of the printed circuit board portion in FIG. 5, and FIG. 7 is a circuit diagram showing an example of a conventional gas alarm. In the figure, 10 is a gas detection unit, 11 is a gas sensor,
12 is a compensation element, 13 and 14 are resistors, 15 is a mounting plate, 16 is a printed circuit board, 17 is a wire mesh, 20 is an indicator/alarm unit, 21 is a power supply circuit, 22 is an alarm circuit,
30 is a line, 31 is a signal line, 40 is a bypass circuit, 41 to 44 are resistors, 45 is a constant voltage diode, 46 is a comparator, 47 is a transistor, 50 is a voltage-current conversion circuit, 51 and 52 are comparators , 53 is a transistor, 54 to 57 are resistors, 60 is a gas detection section, 61 is a sensor case, 62 is a flame arrester, 63 and 64 are sensor guides, 65 is an electric chamber cover, 66 is a gasket, and 67 is a resin fixing section. , is the sensor room, and is the electrical room.

Claims

[Claims for Utility Model Registration] (1) A gas detection section equipped with a gas sensor, a power supply circuit that supplies current to the gas detection section via a line, and an indicator or/and which is operated by the output of the gas detection section. and an indicator/alarm unit having an alarm circuit, characterized in that a bypass circuit is provided in the gas detection unit to detect a change in the current of the gas sensor and maintain a constant voltage applied to the gas sensor. gas alarm. (2) The gas alarm according to claim (1), further comprising a voltage-current conversion circuit that converts the output voltage of the gas sensor into a current output inside the gas detection section. (3) In the gas alarm according to claim (1) or (2), the terminal part of the connector is connected to a printed circuit board that includes a gas sensor, a bypass circuit, and/or a voltage-current conversion circuit inside the gas detection part. A gas alarm comprising a sensor unit having a plug-in structure. (4) In the gas alarm according to any one of claims (1) to (3), the gas sensor is surrounded by a flame arrester, and the gas sensor and a bypass circuit or/and voltage-current converter on a printed circuit board are installed in a sensor case. A gas alarm that features a sensor unit that is separated into a sensor chamber and an electrical chamber by providing a resin-fixed part between the sensor unit and the circuit.