JPS63205795A - Radiant type fire detector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a radiation-type fire detector that detects radiant light emitted from a flame to notify a fire.

<Prior art> Conventionally, radiation fire detectors detect two different spectral components in infrared rays, and by comparing their radiation amounts, they can distinguish between flames, sunlight, or light such as lighting lamps (hereinafter referred to as environmental light). A two-wavelength fire detector that distinguishes between the two wavelengths was known from Japanese Patent Publication No. 16238/1983. According to this publication, the short-wavelength spectral component and the long-wavelength spectral component were detected using two solar cells through a filter, but since some stores malfunctioned due to blue rotating lights of cars, In order to avoid this, the range in which long wavelength spectral components are detected was shifted to a range that does not include these components, and thereby a pyroelectric element was used as the element. Under normal ambient light, the output is a short-wavelength spectrum > long-wavelength spectrum, whereas in the case of radiant light from a flame, the output is a short-wavelength spectrum (long-wavelength spectrum), and this reversal is detected and the occurrence of a fire. I was trying to notify them.

(Problems with conventional technology) Detectors using pyroelectric elements are excellent in that they do not malfunction when exposed to rotating blue lights, etc., but noise output occurs due to changes in ambient temperature, shock, or deterioration. However, there were cases where the above output relationship was reversed and a fire alarm was issued even though there was no fire.

<Means for Solving the Problems> In view of the drawbacks of the above-mentioned conventional fire detectors, the present invention provides a radiation type fire detection system that is less likely to malfunction even when a pyroelectric element is used as an element for detecting long wavelength spectral components. The purpose of this technology is to detect the short-wavelength spectral component and long-wavelength spectral component of the radiant light emitted from the flame using solar cells and pyroelectric elements, respectively, and to detect the short wavelength spectral component and the long-wavelength spectral component of the radiant light emitted from the flame. Wavelength spectral component〉In a radiation type fire detector that emits a fire signal when the wavelength spectral component changes from a long wavelength spectral component to a short wavelength spectral component to a long wavelength spectral component,
The long-wavelength spectrum of radiant light is detected simultaneously by two pyroelectric elements, and a fire signal is issued when the output obtained from them becomes larger than the output of the short-wavelength spectrum component obtained through the solar cell. This is how it was done.

<Function> In the case of a fire, the fire detector configured as described above will detect
The output from the two pyroelectric elements becomes larger than the output from the solar cell, and this causes a fire signal to be issued. Also 2
If one of the pyroelectric elements is normal and the other pyroelectric element produces an output similar to that of a fire due to deterioration or the like, a failure signal is issued.

(Example) In Fig. 0, which describes an example of the radiation fire detector of the present invention using drawings, 11.12 transmits the long wavelength spectrum of flame radiated from the same location, 1.0 to 2.2 μm. Similarly, the filter 13 has a short wavelength spectrum of 0.
A filter 21.22 which makes 8 to 1.08 m equal to i3 is a pyroelectric element, and is provided corresponding to filter I1.12. A solar cell 23 is provided corresponding to the filter 13.

31, 32, and 33 are AC amplifiers, respectively, and the pyroelectric element 2
Among the AC outputs generated at the output resistor R1 provided corresponding to the solar cell 23 and the solar cell 23, the AC output of 3 Hz to 20H2 inputted through the resistor Rt and the condenser C1 is amplified. 41, 42, 43, and 44 are smoothing circuits, of which smoothing circuits 41, 42, and 43 are provided corresponding to amplifiers 31, 32, and 33, and signal line connection terminals P and P' that also serve as power supply. A resistor comprising a series circuit of resistors R3 and R4 connected in parallel between them, a rectifying diode D1 connected to the connection point thereof, and a resistor R1 and capacitor C1 connected in parallel between this and the terminal P°. It is configured in a series circuit with R6, and is connected to amplifiers 31, 32, and 33 through a capacitor C2. The smoothing circuit 44 is configured similarly to the smoothing circuits 41, 42, and 43, but the amplification H3
Each of the resistors R3 and R4 is connected through a rectifying diode D'+ to smooth the output of either or both of the resistors R3 and R4.

51, 52, 53, and 54 are comparators, and the non-in-phase inputs of the comparators 51 to 53 are connected to the corresponding smoothing circuit 41°4.
2 and 43, and the in-phase input of the comparator 54 are connected to the smoothing circuit 44. A comparator 51 provided corresponding to the smoothing circuit 41 and 42 that smoothes the output of the long wavelength spectrum.
．． The in-phase input of the comparator 52 and the non-in-phase input of the comparator 54 are connected to the non-in-phase input of the comparator 53 provided corresponding to the smoothing circuit 43 for smoothing the output of the short wavelength spectrum.
The in-phase input of No. 3 is connected to the output of the smoothing circuit 42.

61 and 62 are integrating circuits, and the delay time of the integrating circuit 61 is set shorter than that of the integrating circuit 62.
PUT (T,) with a resistor R9, a capacitor C4 connected in parallel to it, and a diode D in parallel connected in series to the resistor R9.

The gate of PU'r(TI) is composed of a diode D of a comparator 54 and a resistor R3.

and the cathode side of the diode D is connected to the diode Dt, which is connected to the output of the comparator 51.52. The integrating circuit 62 is composed of a charging resistor R8 and a capacitor CS, and one end of the resistor R1 is connected to a diode D8 provided at the output of the comparator 53.

71 and 72 are switching circuits each composed of a PUT (TZ) and a transistor T, and the switching circuit 71 includes a light emitting diode L as a failure indicator.
1, the switching circuit 72 is provided with a light emitting diode Lx as a fire indicator light, and the switching circuit 72 is provided with a light emitting diode Lx as a fire indicator light.
1 has a Zener diode Z in series with the transistor T1.
When D is connected and the switching circuit 71 operates, the configuration is such that a predetermined voltage remains between the terminals P and P'.

Next, the operation of the radiation type fire detector will be explained.

While the detector is illuminated with environmental light such as sunlight or illumination lights, the spectral components of these lights are in the relationship of short wavelength spectral component > long wavelength spectral component, so the pyroelectric elements 21, 22 and The outputs of the solar cells 23 are amplified by amplifiers 31, 32, 33, and smoothing circuits 41, 42, .
43. The output smoothed in 44 is the output of the smoothing circuit 43>
Since it is the output of smoothing circuit 41, 42, 44, comparison 35
1.52 output is high level, comparators 53 and 54
maintains a low level. In this state, the integrating circuit 6
Capacitor C4 of No. 1 attempts to be charged by the high level outputs of comparators 2S51 and 52, but since the output of comparator 54 is at low level, resistor R9 and PUT (T+)
It is discharged through the battery and cannot work.

Therefore, the integrating circuit 61, 62 and the switching circuit 7
1.72 is not operated, light emitting diodes L1 and L8
is not lit.

When a fire detector is irradiated with radiant light from flames caused by a fire, unlike in the case of environmental light, there is a relationship of long wavelength spectral component>short wavelength spectral component. The outputs are 42 and 44, and comparison 2
The output of S53 becomes high level, and the switching circuit 72 is turned on after a predetermined time through the integrating circuit 62, and the terminals P and P' are almost short-circuited, and a fire signal is sent to a receiver (not shown), and the signal is used as a fire indicator light. light-emitting dion L2 is turned on. Further, since the comparison signals 351 and 52 are at a low level and the comparator 54 is at a high level, the integrating circuit 61 and the switching circuit 71 do not operate, and the light emitting diode as a failure indicator is not lit.

On the other hand, if the pyroelectric element 21 generates a noise output similar to that when a flame is irradiated due to deterioration, the outputs of the smoothing circuits 41 and 44 become larger than the output of the smoothing circuit 43, but the normal pyroelectric element 22 Since the output of the smoothing circuit 42 corresponding to is smaller than the output of the smoothing circuit 43, the comparator 54 is inverted to high level and the comparator 51 is inverted to low level, and the comparator 52 is maintained at high level and the comparator 53 is maintained at low level. Therefore, pu'r(T+) is turned off and capacitor C1 continues to be charged. PUT(T
2) is turned on and the transistor T becomes conductive, so the terminal P
, P' becomes a predetermined voltage determined by the Zener diode F Z D, and a fault signal is sent to the receiver (not shown), and the light emitting diode Ll as a fault indicator lights up, and the pyroelectric element 22 deteriorates, causing a flame. If a noise output similar to that generated when irradiation occurs, the output of the comparator 53 becomes high level and operates the switching circuit 72 through the integrating circuit 62. However, before that, the integrating circuit 61 with a short delay time operates. The light emitting diode F
L is lit, indicating that there is a malfunction.

In the above embodiment, a fire signal is identified by making the terminals p and p' almost short-circuited, and a failure signal is identified by making a predetermined voltage determined by a Zener diode between the terminals. A pulse signal or a fault signal may be identified as a DC signal or in the reverse relationship. In the above embodiment, a switching element such as a transistor operated by the output of the switching circuit 71 may be used to identify the T
It would be even more useful if the base and emitter of the .

<Effects> The radiation type fire detector of the present invention is a radiation type fire detector that does not malfunction even if one of the pyroelectric elements used therein generates an output similar to that of a fire due to deterioration or the like. There is an effect that can be obtained.

[Brief explanation of the drawing]

The drawing is a circuit diagram of an embodiment of the radiation type fire detector of the present invention. 21, 22... Pyroelectric element, 23... Solar cell, 31
．． 32゜33... AC amplifier, 41.42.43.4
4... Smoothing circuit, 51, 52.53.54... Comparator, 61.62... Integrating circuit, 71, 72... Switching circuit.

Claims (1)

[Claims] The short wavelength spectral component and the long wavelength spectral component of the radiant light emitted from the flame are detected by a solar cell and a pyroelectric element, respectively, and the output relationship between the two components is as follows: short wavelength spectral component > long wavelength spectral component to short wavelength. In a radiation-type fire detector that emits a fire signal when the spectral component < long wavelength spectral component, the long wavelength spectral component of the radiant light is simultaneously detected by two pyroelectric elements, and the output from them is transmitted through the solar cell. A radiation type fire detector characterized in that a fire signal is emitted when the output of the short wavelength spectral component becomes larger than the output of the obtained short wavelength spectral component.