JPH06325269A - Ultraviolet ray type sensor - Google Patents

Abstract

PURPOSE:To provide the configuration of an ultraviolet ray type sensor in which the judgement of the issuance of calling to meet the environmental state of an installed place can be executed on a receiver side. CONSTITUTION:This sensor is provided mainly with an oscillation circuit 2 to generate a pulse signal at every constant period, an ultraviolet ray detection circuit 4 to generate a detection signal at the time of the generation of the pulse signal and besides, at the time of the detection of an outside ultraviolet ray, a timer circuit 5 to measure set time, a counter circuit 6 which operates during the time-measurement of the timer circuit 5 and simultaneously, counts the number of times of the generation of the detection signal during the time- measurement of the timer circuit 5 and outputs in digital value a count value Ct, a digital/analog conversion circuit 7 to convert the count value Ct into an analog voltage signal, and a signal terminal LS to output the analog voltage signal to the outside. A signal line connected to a receiver is connected to the signal terminal LS.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet sensor for detecting ultraviolet rays emitted from a flame.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional ultraviolet detector 20 is connected to a receiver 21 such as a fire receiver via a signal line to construct a monitoring system. The ultraviolet ray detector 20 is designed to detect the ultraviolet ray contained in the flame existing in the installation place (movie theater, lobby, warehouse, department store, parking lot, etc.), and the ultraviolet ray of a predetermined level or higher is detected. When the alarm is issued, the alarm is issued, and the built-in output contact 20a is closed to output an alarm signal by no voltage. The fire receiver 21 is
The alarm signal output from the ultraviolet sensor 20 is received via a signal line, and alarm processing such as activating an alarm device is performed.

[0003]

However, the conventional ultraviolet ray sensor is designed to detect even weak ultraviolet rays, which may cause a false alarm due to a small flame of a match or lighter caused by smoking. Therefore, the installation place was limited to places where fire is strictly prohibited or places where there is no fire. Also, if you try to install the UV sensor in a smoking room or a waiting room where there are cigarettes, matches, lighters, etc. with fire, it will not react to small flames such as cigarettes, matches, lighters, etc. It is necessary to adjust the UV sensitivity of the system to be dull, but if this is done, it is not possible to detect the early stage fire that occurred during absence or the absence of people and the arson act by unbelievers / intruders This causes a delay in reporting, such as reporting after it has spread. That is, the conventional ultraviolet sensor has a problem that an accurate alarm cannot be issued when the environmental condition of the installation location changes.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an ultraviolet ray sensor capable of making a warning determination according to the environmental condition of the installation place. To provide a configuration.

[0005]

DISCLOSURE OF THE INVENTION The present invention, which has been made to solve the above-mentioned problems, provides an oscillating means for generating a pulse signal at regular intervals and a detecting means for generating the pulse signal and detecting an external ultraviolet ray. An ultraviolet ray detecting means for generating a signal, a timer means for timing a set time, a counter means for counting the number of times the detection signal is generated during the timing of the timer means and outputting the count value, and an external count value. And a terminal for variably setting a comparison judgment value for the count value, the terminal issuing a signal according to a comparison result between the count value and the comparison judgment value. It is an ultraviolet sensor characterized by connecting a signal line connected to the machine.

[0006]

According to the present invention, the ultraviolet detector outputs a signal as the count value of the number of times of detection of the ultraviolet rays within the set time, and based on the count value as the detection amount of the ultraviolet rays contained in the flame for detecting the count value. It is possible to determine the alarm on the receiver side, and the comparison judgment value for making the alarm determination can be variably set on the receiver side, depending on the environmental condition of the installation location of the ultraviolet sensor. By adjusting the comparative judgment value, it is possible to issue an accurate alarm according to the environmental condition of the installation place.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit block diagram showing an embodiment of an ultraviolet sensor according to the present invention. The ultraviolet sensor shown in FIG. 1 includes a power supply terminal Lv for connecting a power supply line connected to a receiver (not shown), a signal terminal Ls for connecting a signal line connected to the receiver, and the power supply. It has a terminal Lv and a common terminal C for each of the signal terminals Ls. The receiver is adapted to supply a DC power supply voltage of 15V to 33V to the UV sensor via a power line, and the UV sensor receives the power voltage via the power terminal Lv. .

Reference numeral 1 denotes a power supply circuit, which supplies a power supply voltage of DC 15V to 33V received via the power supply terminal Lv to DC 5
It is converted to V and supplied to each circuit block described later.

An oscillating circuit 2 generates a pulse signal having a pulse width of 4 microseconds at a constant cycle, for example, every 50 milliseconds. Reference numeral 3 denotes a booster circuit, which is composed of a booster transformer and the like. The booster circuit 3 appropriately boosts the voltage of the pulse signal generated in the oscillator circuit 2 and outputs the boosted pulse signal.

Reference numeral 4 is an ultraviolet detection circuit. The ultraviolet ray detecting circuit 4 connects an adjusting resistor R and an output resistor r to both ends of an ultraviolet ray detecting tube S which detects and discharges only ultraviolet rays having a wavelength of 185 to 260 nm, and a capacitance C1 is connected to both ends of the resistor r. Is a series circuit formed by connecting. The high-voltage pulse signal output from the booster circuit 3 is applied to the ultraviolet detection circuit 4. The ultraviolet detection tube S is
When voltage is applied to both ends of the pulse signal, that is, each time the pulse signal is generated, external ultraviolet rays can be detected, and when external ultraviolet rays are detected at this time, discharge is rapidly performed. ing. A pulse current flows through the output resistance r due to the discharge of the ultraviolet ray detection tube S, and a pulse voltage signal is generated across the output resistance r. The ultraviolet ray detection circuit 4 outputs the pulse voltage signal as a detection signal.

Reference numeral 5 is a timer circuit, for example, 5 to 29.
Measures the set time in seconds. The timer circuit 5 starts timing with the detection signal from the ultraviolet ray detection circuit 4 as a trigger signal in the non-timekeeping state, and stops when the set time is finished. The timer circuit 5 continuously outputs the timing signal only during the timing operation.

Reference numeral 6 is a counter circuit, which is a circuit formed by combining flip-flops. The counter circuit 6 takes in the detection signal from the ultraviolet ray detection circuit 4 and the timing signal from the timer circuit, and operates only while the timing signal is being input. That is, the counter circuit 6 operates only during the time counting operation of the timer circuit 5. The counter circuit 6 counts the number of times the detection signal is generated from "0" only during its operation. or,
When the output of the clock signal is stopped, the counter circuit 6 digitally outputs the count value Ct counted up to that time, and the count value Ct stored in the counter circuit 6 is reset, so that the clock signal When is input again, the detection signal is counted from "0 times" again.

Reference numeral 7 denotes a digital / analog conversion circuit (D / A
The counter circuit 6 converts the count value Ct digitally output from the counter circuit 6 into an analog voltage signal having a level corresponding to the level of the count value Ct, and outputs the analog voltage signal.

Reference numeral 8 is a peak hold circuit, which holds and outputs the signal level of the analog voltage signal from the digital / analog conversion circuit 7. At this time, the peak hold circuit 8 holds and outputs the signal level of the currently input analog voltage signal until the next analog voltage signal is input.

Reference numeral 9 is an amplifier circuit, which appropriately amplifies the analog voltage signal output from the peak hold circuit. The analog voltage signal output from the amplifier circuit 9 is
A data signal is output from between the signal terminal Ls and the common terminal C and transmitted to the receiver via the signal line.

It should be noted that the detected amount of ultraviolet rays detected by the ultraviolet ray detection circuit 4, that is, the scale of the detected flame can be grasped based on the number of times the detection signal is generated (count value Ct) within the set time. That is, the larger the number of times the detection signal is generated (count value Ct) within the set time, the more the flame can be determined to be relatively large enough to cause the ultraviolet detection tube S to react relatively stably. In addition, as the number of times the detection signal is generated (count value Ct) is smaller, it can be determined that the flame is of a relatively small scale depending on whether the ultraviolet detection tube S reacts or not. The ultraviolet ray sensor outputs an analog voltage of a level corresponding to the detected amount of ultraviolet rays detected by the ultraviolet ray detecting circuit 4.

The count value Ct based on the analog voltage signal output from the ultraviolet sensor is transmitted to the receiver via the signal line. The receiver is
The comparison judgment value Cs for the count value Ct can be set by an analog voltage.
Can be variably set. The receiver is adapted to judge whether or not to issue an alarm by level-comparing the count value Ct and the comparison judgment value Cs, and the level of the count value Ct is equal to the comparison judgment value Cs. When a comparison result that exceeds the level is output, a warning process such as operating an alarm device is performed.

Further, according to the environmental condition of the installation location of the ultraviolet sensor, the comparison judgment value Cs in the receiver is obtained.
Can be adjusted. That is, for example, when the ultraviolet sensor is installed in a place where fire is strictly prohibited, the comparative judgment value Cs for the ultraviolet sensor is set to be low,
Make sure to notify even minute flames such as matches and lighters. Further, when the ultraviolet detector is installed in a place where there is a fire such as a cigarette or a lighter, such as a smoking room or a lobby, the comparative judgment value Cs for the ultraviolet detector is set to be high. , Don't be notified of minute flames such as matches and lighters. However, even in such a place where there is a fire, the comparative judgment value Cs is reset to a lower value when it is in a locked state due to the absence of a person at midnight or due to absence. Also, be sure to notify even minute flames such as matches and lighters. In this case, the operation of the comparison determination value Cs may be linked to a crime prevention sensor or the like. By doing this, it is possible to detect arson acts by unbelievers and intruders and early fires at an early stage.

As described above, the ultraviolet ray detector can be used not only as a fire detector but also as an arson sensor for detecting an arson act by unbelievers and intruders.

In the ultraviolet sensor, the ultraviolet detection sensitivity can be adjusted. For example, the higher the voltage applied to both ends of the ultraviolet ray detection tube S, the easier it is to detect and discharge weak ultraviolet rays. Therefore, if the resistance value of the adjusting resistor R is set small, The voltage applied to both ends of the detector tube S increases,
The ultraviolet ray detection sensitivity of the ultraviolet ray detection tube S becomes sensitive. or,
As another method, by setting a long setting time of the timer circuit 5 or increasing an amplification factor of the amplification circuit 9, a high level analog voltage signal is output even when low level ultraviolet rays are detected. As obtained, it is possible to substantially increase the sensitivity of ultraviolet ray detection.

In the present embodiment, the count value Ct output from the counter circuit 6 is not limited to being converted into an analog voltage signal and output.
Alternatively, t may be represented by a binary number and output as a digital value signal.

[0023]

According to the present invention configured as described above, it is possible to make a warning determination according to the environmental condition of the installation place,
It is possible to prevent the occurrence of false alarms and delays in reporting as much as possible.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing one form of a conventional monitoring system.

[Explanation of symbols]

 2 Oscillation circuit 4 Ultraviolet ray detection circuit 5 Timer circuit 6 Counter circuit 7 Digital / analog conversion circuit

Claims (1)

[Claims] 1. An oscillating means for generating a pulse signal at regular intervals, an ultraviolet ray detecting means for generating a detection signal when the pulse signal is generated and an external ultraviolet ray is detected, and a timer means for counting a set time. The counter means is provided with a counter means for counting the number of times the detection signal is generated during the time counting of the timer means and outputting the count value, and a terminal for outputting the count value as a signal to the outside. A receiver for variably setting a comparison judgment value with respect to a value, wherein a signal line connected to the receiver for issuing a notification according to a comparison result between the count value and the comparison judgment value is connected. Type detector.