JPS586195B2 - Fire detector constant voltage circuit - Google Patents
Fire detector constant voltage circuitInfo
- Publication number
- JPS586195B2 JPS586195B2 JP51007154A JP715476A JPS586195B2 JP S586195 B2 JPS586195 B2 JP S586195B2 JP 51007154 A JP51007154 A JP 51007154A JP 715476 A JP715476 A JP 715476A JP S586195 B2 JPS586195 B2 JP S586195B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- constant voltage
- voltage
- fire detector
- voltage circuit
- 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.)
- Expired
Links
Landscapes
- Fire-Detection Mechanisms (AREA)
- Fire Alarms (AREA)
Description
【発明の詳細な説明】
本発明はデイプレツション形の電界効果トランジスタを
用いた火災感知器の定電圧回路に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a constant voltage circuit for a fire detector using a depletion type field effect transistor.
火災感知器の定電圧回路において入力電圧が変動しても
該回路の消費電流を必要最小限に押えるために、該回路
のツエナダイオードに直列に定電流回路を付加し常に該
ツエナダイオードに一定電流を流すようにしたバイポー
ラ形のトランジスタとツエナダイオードなどよりなるも
のが知られていた。In order to suppress the current consumption of the constant voltage circuit of a fire detector to the necessary minimum even if the input voltage fluctuates, a constant current circuit is added in series with the Zener diode of the circuit, so that the constant current always flows through the Zener diode. Some devices were known that consisted of bipolar transistors that allowed current to flow, and Zener diodes.
しかし上記定電圧回路では定電流回路が付加されるので
高価となる欠点があり、またバイポーラ形のトランジス
タはその動作が電流制御であるために常に一定以上の電
流をベース回路に流す必要があるので消費電流を削減す
るにも限界があった。However, the constant voltage circuit described above has the disadvantage of being expensive because it requires a constant current circuit, and since bipolar transistors operate under current control, a current above a certain level must always flow through the base circuit. There was also a limit to how much current consumption could be reduced.
本発明は以上の点にかんがみ動作が電圧で制御されかつ
その電圧が零でも動作するデイプレツション形の電界効
果トランジスタを定電圧回路に用いることにより、定電
流回路が不要となり安価でかつ消費電流の少ない火災感
知器の定電圧回路を提供するものである。In view of the above points, the present invention uses a depletion type field effect transistor whose operation is controlled by voltage and operates even when the voltage is zero in a constant voltage circuit, thereby eliminating the need for a constant current circuit, resulting in low cost and low current consumption. This provides a constant voltage circuit for fire detectors.
以下本発明の一実施例を第1図について説明すると、定
電圧を必要とするイオン室または半導体感熱素子および
それらのスイッチング素子を含む増幅素子などより構成
される火災検出回路Dには、動作が電圧で制御されかつ
その電圧が零でも動作するデイプレツション形の電界効
果トランジスタFETが直列に接続され、該トランジス
タFETのドレインdと上記検出回路Dの一端が火災感
知器の正負の電源端子a,a’に接続される。An embodiment of the present invention will be described below with reference to FIG. 1. A fire detection circuit D consisting of an ion chamber or a semiconductor heat-sensitive element that requires a constant voltage, and an amplification element including a switching element thereof, has no operation. A depletion type field effect transistor FET that is controlled by a voltage and operates even when the voltage is zero is connected in series, and the drain d of the transistor FET and one end of the detection circuit D are connected to the positive and negative power terminals a and a of the fire detector. ' is connected to '.
また上記火災検出回路Dには、ツエナダイオードZDと
抵抗Rとの直列回路で構成される分圧器が並列に接続さ
れると共に、該抵抗Hの両端に上記トランジスタFET
のゲートgとソースSとが接続される。Further, a voltage divider constituted by a series circuit of a Zener diode ZD and a resistor R is connected in parallel to the fire detection circuit D, and the transistor FET is connected to both ends of the resistor H.
The gate g and source S of are connected.
上記回路に電流が投入されると、電界効果トランジスタ
FETを通して火災検出回路Dにドレイン電流が流れ、
該検出回路Dの電圧が分圧器のツエナダイオードZDの
ツエナ電圧以上になると、ツエナダイオードZDを通し
て抵抗Rに微少な電流が流れ、該抵抗Rの両端の電圧す
なわちトランジスタFETのゲート・ソース間電圧と、
検出回路Dと分圧器とのインピーダンスで定まる一定の
ドレイン電流が該検出回路Dに流れ検出回路Dは一定電
圧に保持される。When a current is applied to the above circuit, a drain current flows to the fire detection circuit D through the field effect transistor FET,
When the voltage of the detection circuit D exceeds the Zener voltage of the Zener diode ZD of the voltage divider, a small current flows through the Zener diode ZD to the resistor R, and the voltage across the resistor R, that is, the gate-source voltage of the transistor FET. ,
A constant drain current determined by the impedance of the detection circuit D and the voltage divider flows through the detection circuit D, and the detection circuit D is held at a constant voltage.
このような状態において入力電圧が変動してもトランジ
スタFETは定電流作用を有するのでドレイン電流が変
化せず火災検出回路Dの電圧が一定に保持される。In such a state, even if the input voltage fluctuates, the transistor FET has a constant current function, so the drain current does not change and the voltage of the fire detection circuit D is held constant.
また火災感知器における火災検出回路Dは一般的に監視
時において負荷変動が少ないように設計されるので、検
出回路Dの負荷変動によって該検出回路Dに流れる電流
が多少変化してもそれによって生ずる抵抗Hの両端の電
圧変化は少なく、従って定電圧回路の出力電圧の変化も
少ないので検出回路Dの電圧はほぼ一定に持続される。In addition, the fire detection circuit D in a fire detector is generally designed to have little load fluctuation during monitoring, so even if the current flowing through the detection circuit D changes somewhat due to load fluctuation of the detection circuit D, this will not cause any change in the current flowing through the detection circuit D. Since the voltage change across the resistor H is small, and therefore the output voltage of the constant voltage circuit is also small, the voltage of the detection circuit D is maintained almost constant.
第2図は本発明の他の実施例で、電界効果トランジスタ
がバイポーラ形のトランジスタTと共にコンブリメンタ
リ接続された電界効果トランジスタFETよりなり、該
トランジスタFET ,Tが火災検出回路Dの一端と電
源端子a間に接続される以外は第1図の実施例と同一の
構成および作用をするので同一符号を付して説明を省略
する。FIG. 2 shows another embodiment of the present invention, in which the field effect transistor is composed of a field effect transistor FET connected complementary to a bipolar type transistor T, and the transistor FET, T is connected to one end of the fire detection circuit D and the power supply. Except for the connection between terminals a, the structure and operation are the same as those of the embodiment shown in FIG.
上記回路では火災検出回路Dに両トランジスタFET,
TのIDとhFEとの積で定まる大きな電流を流すこと
ができると共に負荷変動に強い定電圧回路が得られる。In the above circuit, fire detection circuit D includes both transistors FET,
A constant voltage circuit that can flow a large current determined by the product of T's ID and hFE and is resistant to load fluctuations can be obtained.
また第1図の実施例では火災検出回路Dのスイッチング
素子を電源端子a,a’間に設けなければ感知器の動作
時に十分な信号電流が得られない場合もあるが、第2図
の実施例ではスイッチング素子を電源端子a,a’間に
設ける必要がなくなる。Furthermore, in the embodiment shown in FIG. 1, if the switching element of the fire detection circuit D is not provided between the power supply terminals a and a', sufficient signal current may not be obtained when the sensor is operating, but in the embodiment shown in FIG. In the example, there is no need to provide a switching element between the power supply terminals a and a'.
また上記実施例では分圧器がツエナダイオードZDと抵
抗Rとより構成されたが、火災検出回路Dの負荷変動の
ほとんどないものでは、ツエナダイオードZDの代わり
に抵抗を用いることもできる。Further, in the above embodiment, the voltage divider is composed of the Zener diode ZD and the resistor R, but if the fire detection circuit D has almost no load fluctuation, a resistor can be used instead of the Zener diode ZD.
この場合ツエナダイオードの動作を定定させるための電
流を該ツエナダイオードに流す必要がなくなるので、さ
らに定電圧回路の消費電流が削減できる。In this case, there is no need to flow a current through the Zener diode for regulating its operation, so that the current consumption of the constant voltage circuit can be further reduced.
本発明は以上のように構成され動作するので、定電流回
路が不要となり安価でかつ消費電流の少ない火災感知器
の定電圧回路が得られる効果がある。Since the present invention is constructed and operated as described above, it is possible to obtain an inexpensive constant voltage circuit for a fire detector that does not require a constant current circuit and consumes less current.
第1図および第2図は共に本発明火災感知器の定電圧回
路の異なる実施例を示す回路図である。
D・・・・・・火災検出回路、FET・・・・・・デイ
プレソション形の電界効果トランジスタ、T・・・・・
・バイポーラ形のトランジスタ、R・・・・・・分圧器
の一部を構成する抵抗、ZD・・・・・・分圧器の一部
を構成するツエナダイオード。1 and 2 are circuit diagrams showing different embodiments of the constant voltage circuit of the fire detector of the present invention. D: Fire detection circuit, FET: Depension type field effect transistor, T:
・Bipolar transistor, R... Resistor forming part of the voltage divider, ZD... Zener diode forming part of the voltage divider.
Claims (1)
ンジスタが直列にまた分圧器が並列に接続され、該分圧
器の出力端に上記トランジスタのゲートとソースが接続
されることを特徴とする火災感知器の定電圧回路。 2 分圧器が抵抗とツエナイダオードとの直列回路より
構成される特許請求の範囲第1項記載の火災感知器の定
電圧回路。 3 分圧器が抵抗より構成される特許請求の範囲第1項
記載の火災感知器の定電圧回路。 4 電界効果トランジスタがバイポーラ形のトランジス
タと共にコンブリメンクリ接続された電界効果トランジ
スタより構成される特許請求の範囲第1項または第2項
または第3項記載の火災感知器の定電圧回路。[Claims] 1. A fire detection circuit is characterized in that a depletion type field effect transistor is connected in series and a voltage divider is connected in parallel, and the gate and source of the transistor are connected to the output terminal of the voltage divider. constant voltage circuit for fire detectors. 2. A constant voltage circuit for a fire detector according to claim 1, wherein the voltage divider is constituted by a series circuit of a resistor and a zener diode. 3. A constant voltage circuit for a fire detector according to claim 1, wherein the voltage divider is comprised of a resistor. 4. The constant voltage circuit for a fire detector according to claim 1, 2, or 3, wherein the field effect transistor is constructed of a field effect transistor connected in combination with a bipolar type transistor.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP51007154A JPS586195B2 (en) | 1976-01-27 | 1976-01-27 | Fire detector constant voltage circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP51007154A JPS586195B2 (en) | 1976-01-27 | 1976-01-27 | Fire detector constant voltage circuit |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5291399A JPS5291399A (en) | 1977-08-01 |
JPS586195B2 true JPS586195B2 (en) | 1983-02-03 |
Family
ID=11658140
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP51007154A Expired JPS586195B2 (en) | 1976-01-27 | 1976-01-27 | Fire detector constant voltage circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS586195B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60194295U (en) * | 1984-06-01 | 1985-12-24 | 石川島播磨重工業株式会社 | Seal structure of pressure vessel door |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4945030U (en) * | 1972-07-27 | 1974-04-20 |
-
1976
- 1976-01-27 JP JP51007154A patent/JPS586195B2/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60194295U (en) * | 1984-06-01 | 1985-12-24 | 石川島播磨重工業株式会社 | Seal structure of pressure vessel door |
Also Published As
Publication number | Publication date |
---|---|
JPS5291399A (en) | 1977-08-01 |
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