JPH0542560Y2 - - Google Patents
Info
- Publication number
- JPH0542560Y2 JPH0542560Y2 JP1984077367U JP7736784U JPH0542560Y2 JP H0542560 Y2 JPH0542560 Y2 JP H0542560Y2 JP 1984077367 U JP1984077367 U JP 1984077367U JP 7736784 U JP7736784 U JP 7736784U JP H0542560 Y2 JPH0542560 Y2 JP H0542560Y2
- Authority
- JP
- Japan
- Prior art keywords
- light
- output
- receiving element
- reference voltage
- light receiving
- 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 - Lifetime
Links
- 239000000779 smoke Substances 0.000 claims description 22
- 238000001514 detection method Methods 0.000 claims description 19
- 230000003287 optical effect Effects 0.000 claims description 14
- 230000003321 amplification Effects 0.000 claims description 8
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 8
- 230000035945 sensitivity Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000000149 argon plasma sintering Methods 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
- Fire-Detection Mechanisms (AREA)
Description
【考案の詳細な説明】
[技術分野]
本考案は比較的長い距離にわたつて煙の有無を
監視するための減光式煙感知器に関するものであ
る。[Detailed Description of the Invention] [Technical Field] The present invention relates to a dimming type smoke detector for monitoring the presence or absence of smoke over a relatively long distance.
[背景技術]
一般にトンネルや広い倉庫あるいはビルの排気
ダクト内のように広くて煙が拡散し易い場所にお
いては、光散乱式やイオン式の煙感知器では火災
の早期発見が困難な場合があり、長い距離を見通
すことのできる減光式煙感知器を用いた方が有利
なことが多い。しかしこの方式は投受光器が分離
して設置されるために、日照その他の温度条件が
異なり互いに温度の影響が相殺されない場合が多
く、したがつて投受光器共に温度補償を行なう必
要がある。一方この種の減光式煙感知器において
は、車のライトなどの外乱光や各種照明器具、特
に省電力型の高周波照明器具(数+KHz)などの
影響を防ぐためにより高い周波数で変調するのが
有利であるが、その場合投光器の発光出力の温度
補償はサーミスタなどで容易にできても、受光器
の検波部の温度特性の補償が容易でないという問
題があつた。[Background technology] In general, in large areas where smoke easily spreads, such as in tunnels, large warehouses, or building exhaust ducts, it may be difficult to detect fires early with light scattering type or ion type smoke detectors. It is often advantageous to use dimming smoke detectors that can see over long distances. However, in this method, since the light emitter and receiver are installed separately, the sunlight and other temperature conditions are different, and the effects of temperature often do not cancel each other out. Therefore, it is necessary to perform temperature compensation for both the light emitter and receiver. On the other hand, this type of dimming type smoke detector modulates at a higher frequency to prevent the influence of ambient light such as car lights and various lighting equipment, especially power-saving high frequency lighting equipment (several + KHz). However, in this case, although the temperature compensation of the light emission output of the light emitter can be easily performed using a thermistor or the like, there is a problem in that it is not easy to compensate for the temperature characteristics of the detection section of the light receiver.
[考案の目的]
本考案は上記の問題点に鑑み為されたものであ
り、高周波で変調された光信号を用いて外乱ノイ
ズを防止するようにした投受光器分離型煙感知器
において、検波部を含む受光器の温度特性を確実
に補償して、常に正確な感度を維持できるように
することを目的とするものである。[Purpose of the invention] The present invention has been developed in consideration of the above-mentioned problems, and aims to provide a smoke detector with separate emitter and receiver that uses a high-frequency modulated optical signal to prevent external noise, by reliably compensating for the temperature characteristics of the receiver including the detection unit, thereby always maintaining accurate sensitivity.
[考案の開示]
しかして本考案減光式煙感知器は、投光部と受
光部とを分離して設置し受光光束の減光率を測定
することにより光路内の煙の有無を感知するよう
にした構成において、投光部より高周波で変調さ
れた光信号を間欠的に投光せしめると共に、受光
部において受光素子の出力と上記変調周波と同一
周波数の基準電圧信号発振器の出力とを交互に切
り換えて増幅検波回路に入力し、両検波出力を比
較せしめることにより増幅検波回路の温度補償を
行なうようにした点に特徴を有するものであり、
それによつて切換用スイツチ素子以降の温度特性
の変化の影響をなくしたものである。[Disclosure of the invention] The attenuation type smoke detector of the present invention detects the presence or absence of smoke in the optical path by installing the light emitting part and the light receiving part separately and measuring the attenuation rate of the received light beam. In this configuration, the light emitter intermittently emits an optical signal modulated at a high frequency, and the light receiver alternately outputs the output of the light receiving element and the output of the reference voltage signal oscillator having the same frequency as the modulation frequency. It is characterized in that the temperature compensation of the amplification and detection circuit is performed by switching the detection output to the amplification and detection circuit and comparing both detection outputs.
This eliminates the influence of changes in temperature characteristics after the switching element.
図は本考案減光式煙感知器の一実施例を示した
ものである。図において、投光部1と受光部2と
はトンネル内などで例えば100m離して設置され
るものであり、煙検出時に線間短絡信号を送る信
号線3を通して、受信機4から常時電源電流が供
給されている。投光部1には間欠的に電源電流が
供給されており、そのために高周波発振器5によ
つて変調された光信号が発光素子6から間欠的に
発せられる。Qは変調用トランジスタ、R1,R2
は電流制限抵抗、THは温度補償用サーミスタで
ある。受光部2では受光素子7と基準電圧発振器
8の出力とが、スイツチ素子9によつて交互に切
り換えられて増幅回路10および検波回路11に
入力される。ここで、基準電圧発振器8は温度変
化に関係のない一定出力を生じるものであり、例
えば温度補償コンデンサやサーミスタなどの温度
補償素子を用いて出力を一定にしてある。検波回
路11の出力はマイクロプロセツサを用いた制御
回路12によつて判定され、一定レベル以下の場
合には受信機4へ煙検出信号が送られる。また制
御回路12では受光信号の判定を行なう毎にスイ
ツチ素子9に制御信号を送つて、増幅回路10の
入力を基準電圧発振器8に切り換え、検波出力の
比較を行なう。実際には投光部1と同様に受光部
にも間欠的に電源電流(5秒毎に数十mSの幅の
パルス電流)が供給され、1パルス期間内に増幅
回路およびクロツクを安定させると共に受光信号
と基準電圧信号の測定と判定とを行なつている。 The figure shows an embodiment of the dimming type smoke detector of the present invention. In the figure, a light emitting unit 1 and a light receiving unit 2 are installed, for example, 100 m apart in a tunnel, etc., and a power supply current is constantly supplied from a receiver 4 through a signal line 3 that sends a line short circuit signal when smoke is detected. Supplied. A power supply current is intermittently supplied to the light projecting section 1, so that an optical signal modulated by the high frequency oscillator 5 is intermittently emitted from the light emitting element 6. Q is a modulation transistor, R 1 , R 2
is a current limiting resistor, and TH is a temperature compensation thermistor. In the light receiving section 2, the output of the light receiving element 7 and the reference voltage oscillator 8 are alternately switched by a switch element 9 and inputted to an amplifier circuit 10 and a detection circuit 11. Here, the reference voltage oscillator 8 generates a constant output regardless of temperature changes, and uses a temperature compensating element such as a temperature compensating capacitor or a thermistor to keep the output constant. The output of the detection circuit 11 is determined by a control circuit 12 using a microprocessor, and if the output is below a certain level, a smoke detection signal is sent to the receiver 4. In addition, the control circuit 12 sends a control signal to the switch element 9 every time the received light signal is determined, switches the input of the amplifier circuit 10 to the reference voltage oscillator 8, and compares the detected outputs. In reality, like the emitter 1, the light receiver is intermittently supplied with power supply current (pulse current with a width of several tens of milliseconds every 5 seconds), which stabilizes the amplifier circuit and clock within one pulse period. The light reception signal and the reference voltage signal are measured and judged.
いま、基準信号電圧をAi、受光信号電圧をXi、
増幅回路10の利得をα、検波回路11の検波効
率をφ、基準信号電圧及び受光信号電圧の増幅検
波後の出力を夫々Ao,Xoとすると、
Xo=Xi・α・φ …(1)
Ao=Ai・α・φ …(2)
となり、(1)、(2)式から、
Xi=(Ai/Ao)×Xo …(3)
が得られる。ここで、(3)式は温度変化による増幅
回路10の利得の変動や検波回路11の検波効率
の変動に影響されない受光信号出力を得られるこ
とを意味する。ここで、上記演算は制御回路12
が行う。なお、基準電圧発振器8の出力は温度補
償を行つても完全に一定にすることは難しいが、
ある程度一定であれば、減光式煙感知器の特性と
して問題とならない程度の正確な感度を維持でき
る。 Now, the reference signal voltage is Ai, the received light signal voltage is Xi,
If the gain of the amplifier circuit 10 is α, the detection efficiency of the detection circuit 11 is φ, and the outputs after amplification and detection of the reference signal voltage and light reception signal voltage are Ao and Xo, respectively, Xo=Xi・α・φ…(1) Ao =Ai・α・φ…(2), and from equations (1) and (2), Xi=(Ai/Ao)×Xo…(3) is obtained. Here, equation (3) means that it is possible to obtain a light-receiving signal output that is not affected by variations in the gain of the amplifier circuit 10 and variations in the detection efficiency of the detection circuit 11 due to temperature changes. Here, the above calculation is performed by the control circuit 12.
will do. Note that it is difficult to keep the output of the reference voltage oscillator 8 completely constant even with temperature compensation;
If it is constant to some extent, it is possible to maintain accurate sensitivity to the extent that it does not pose a problem as a characteristic of a dimming type smoke detector.
[考案の効果]
本考案は上述のように、投光部と受光部とを分
離して配置し、受光光束の減光率を測定して光路
内の煙の有無を感知する減光式煙感知器におい
て、高周波で変調された光信号を間欠的に投光す
る投光部とし、投光部からの光信号を受光する受
光素子と、上記投光部から投光される光信号と同
一周波数で変調され温度変化に関係なく略一定レ
ベルの信号を発生する基準電圧発生手段と、この
基準電圧発生手段の出力と受光素子の出力とを交
互に切換出力する切換手段と、この切換手段の出
力を増幅検波する増幅検波手段と、基準電圧発生
手段の出力を増幅検波した出力で、基準電圧発生
手段の出力を割つた値に、受光素子の出力を増幅
検波した出力をかけて、増幅検波手段の温度特性
を相殺した受光素子出力を求める演算手段と、求
められた受光素子の出力に基づいて光路内の煙の
有無を判定する判定手段とを受光部に設けたもの
であり、演算手段で基準電圧発生手段の出力を増
幅検波した出力で、基準電圧発生手段の出力を割
つた値に、受光素子の出力を増幅検波した出力を
かけて、受光素子出力を求めているので、増幅検
波手段における温度変化を相殺した受光素子の出
力を得ることができ、温度変化に影響されない正
確な感度を維持できる。[Effects of the invention] As described above, the present invention provides a smoke attenuation type in which the light emitting part and the light receiving part are arranged separately, and the presence or absence of smoke in the optical path is detected by measuring the attenuation rate of the received light flux. In the sensor, a light emitter that intermittently emits an optical signal modulated with a high frequency is used, and a light receiving element that receives the optical signal from the light emitter is the same as the optical signal emitted from the light emitter. A reference voltage generating means for generating a signal modulated by frequency and having a substantially constant level regardless of temperature changes; a switching means for alternately switching outputs between the output of the reference voltage generating means and the output of the light receiving element; The output of the reference voltage generation means is divided by the output of the amplification and detection means for amplifying and detecting the output, and the output of the reference voltage generation means is multiplied by the output of the light receiving element. The light receiving section is provided with a calculating means for calculating the light receiving element output that cancels out the temperature characteristics of the means, and a determining means for determining the presence or absence of smoke in the optical path based on the determined output of the light receiving element. The output of the light receiving element is obtained by dividing the output of the reference voltage generating means by the output obtained by amplifying and detecting the output of the light receiving element. It is possible to obtain an output of the light-receiving element that offsets temperature changes in the means, and it is possible to maintain accurate sensitivity unaffected by temperature changes.
図は本考案減光式煙感知器の一実施例を示すブ
ロツク回路図である。
1は投光部、2は受光部、3は信号線、4は受
信機、5は高周波発振器、6は発光素子、7は受
光素子、8は基準電圧発振器、9はスイツチ素
子、10は増幅回路、11は検波回路、12は制
御回路、THはサーミスタ、R1,R2は抵抗、Qは
トランジスタ。
The figure is a block circuit diagram showing one embodiment of the dimming type smoke detector of the present invention. 1 is a light emitter, 2 is a light receiver, 3 is a signal line, 4 is a receiver, 5 is a high frequency oscillator, 6 is a light emitting element, 7 is a light receiving element, 8 is a reference voltage oscillator, 9 is a switch element, 10 is an amplification circuit, 11 is a detection circuit, 12 is a control circuit, TH is a thermistor, R 1 and R 2 are resistors, and Q is a transistor.
Claims (1)
束の減光率を測定して光路内の煙の有無を感知
する減光式煙感知器において、高周波で変調さ
れた光信号を間欠的に投光する投光部とし、投
光部からの光信号を受光する受光素子と、上記
投光部から投光される光信号と同一周波数で変
調され温度変化に関係なく略一定レベルの信号
を発生する基準電圧発生手段と、この基準電圧
発生手段の出力と受光素子の出力とを交互に切
換出力する切換手段と、この切換手段の出力を
増幅検波する増幅検波手段と、基準電圧発生手
段の出力を増幅検波した出力で、基準電圧発生
手段の出力を割つた値に、受光素子の出力を増
幅検波した出力をかけて、増幅検波手段の温度
特性を相殺した受光素子出力を求める演算手段
と、求められた受光素子の出力に基づいて光路
内の煙の有無を判定する判定手段とを受光部に
設けて成る減光式煙感知器。 (2) 投光部の発光素子に直列に温度補償用のサー
ミスタを接続して成ることを特徴とする実用新
案登録請求の範囲第1項記載の減光式煙感知
器。[Scope of Claim for Utility Model Registration] (1) A dimming type smoke detector in which a light emitting part and a light receiving part are arranged separately, and the attenuation rate of the received light beam is measured to detect the presence or absence of smoke in the optical path. , a light projecting section that intermittently emits an optical signal modulated at a high frequency, a light receiving element that receives the optical signal from the light projecting section, and a light receiving element that receives the optical signal from the light projecting section at the same frequency as the light signal emitted from the light projecting section. A reference voltage generating means that generates a modulated signal at a substantially constant level regardless of temperature changes, a switching means that alternately switches between the output of the reference voltage generating means and the output of the light receiving element, and an output of the switching means. The output of the reference voltage generation means is divided by the output of the amplification detection means for amplification and detection and the output of the reference voltage generation means is multiplied by the output of the amplification and detection of the output of the light receiving element. A light-reducing smoke detector comprising a light-receiving section provided with a calculation means for obtaining a light-receiving element output that cancels temperature characteristics, and a determining means for determining the presence or absence of smoke in an optical path based on the obtained output of the light-receiving element. (2) The attenuation type smoke detector according to claim 1, which is a utility model registration, characterized in that a thermistor for temperature compensation is connected in series with the light emitting element of the light projecting part.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7736784U JPS60192091U (en) | 1984-05-25 | 1984-05-25 | Dimming smoke detector |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7736784U JPS60192091U (en) | 1984-05-25 | 1984-05-25 | Dimming smoke detector |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS60192091U JPS60192091U (en) | 1985-12-20 |
JPH0542560Y2 true JPH0542560Y2 (en) | 1993-10-26 |
Family
ID=30620372
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP7736784U Granted JPS60192091U (en) | 1984-05-25 | 1984-05-25 | Dimming smoke detector |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS60192091U (en) |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5127379A (en) * | 1974-08-30 | 1976-03-06 | Nippon Signal Co Ltd | KEMURI KANCHIKI |
JPS53145498A (en) * | 1977-05-24 | 1978-12-18 | Hochiki Co | Method of preventing wrong operation of reception transmission alarm |
JPS5631625A (en) * | 1979-08-24 | 1981-03-31 | Hochiki Corp | Smoke detector of photoelectronic type |
JPS5839552B2 (en) * | 1975-12-29 | 1983-08-30 | ハヤミ オサム | Golf training guide |
JPS58218640A (en) * | 1982-06-14 | 1983-12-19 | Seikosha Co Ltd | Smoke detector |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5839552U (en) * | 1981-09-10 | 1983-03-15 | 能美防災工業株式会社 | Light emitting part of dimming type smoke detector |
-
1984
- 1984-05-25 JP JP7736784U patent/JPS60192091U/en active Granted
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5127379A (en) * | 1974-08-30 | 1976-03-06 | Nippon Signal Co Ltd | KEMURI KANCHIKI |
JPS5839552B2 (en) * | 1975-12-29 | 1983-08-30 | ハヤミ オサム | Golf training guide |
JPS53145498A (en) * | 1977-05-24 | 1978-12-18 | Hochiki Co | Method of preventing wrong operation of reception transmission alarm |
JPS5631625A (en) * | 1979-08-24 | 1981-03-31 | Hochiki Corp | Smoke detector of photoelectronic type |
JPS58218640A (en) * | 1982-06-14 | 1983-12-19 | Seikosha Co Ltd | Smoke detector |
Also Published As
Publication number | Publication date |
---|---|
JPS60192091U (en) | 1985-12-20 |
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