JPH05256699A - Ultraviolet detector - Google Patents

Abstract

PURPOSE:To obtain an ultraviolet detecting tube utilizing detector that handily operable at a job site and inexpensive in cost by boosting and rectifying the direct current of a direct current power source into the high tension direct current with a high voltage drive circuit, and impressing it to an ultraviolet detecting tube. CONSTITUTION:When ultraviolet rays are incident to an ultraviolet detecting tube 1, discharge starts. A discharge current instantaneously flows into a resistor 4 by an electric charge so far charged to a capacitor 3 mainly, thus a fine pulse voltage is generated. If the charge of the capacitor is decreased, the discharge is temporarily stopped. In this connection, this resistor 4 is one that is used for taking out the discharge current in the shape of a voltage pulse. A discriminator 5 operates the number of discharge frequency per specified time of the inputted pulse voltage, outputting it to a display circuit 7 as a pulse number per the specified time. The display circuit 7 displays the pulse number per the specified time digitally on a display board 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet ray detector for detecting ultraviolet rays, and more particularly to an ultraviolet ray detector in a field of installation of a flame type detector operated by ultraviolet rays emitted from a flame.

[0002]

2. Description of the Related Art Flame detectors used for notification of a fire are generally classified into those that detect infrared rays and those that detect ultraviolet rays. A sensor for detecting infrared rays is used in a tunnel or the like because of its characteristic of detecting a wide range, and a sensor for detecting ultraviolet rays is installed in a large space.

An ultraviolet ray detection tube such as a UV tron is usually used to detect ultraviolet rays. The UV tron is a sensor that is sensitive only to ultraviolet rays with a wavelength of 260 nm or less,
It features high sensitivity, high output, and high-speed response, and is said to be most suitable for flame detection and discharge phenomenon detection.

FIG. 2 shows the configuration of the flame detector. In the figure, 21 is a DC power source, 22 is an oscillation circuit, 23 is a transistor, 24 and 25 are diodes, 26 is a transformer, 27.
Is a smoothing capacitor, 28 is a UV tron, 29 and 30 are resistors, 31 is a capacitor, 32 is a control circuit, and 33 is a fire signal generation circuit. The DC voltage of the DC power supply 21 is boosted and rectified by a high voltage drive circuit A composed of an oscillation circuit 22, a transistor 23, transistors 24, 25 and a transformer 26, and the high voltage DC is applied to a UV tron 28 via a smoothing capacitor 27. .. When ultraviolet rays emitted by a fire flame enter the UV tron 28 to which a high DC voltage is applied, the UV tron 28 starts discharging and generates a voltage in the resistor 29 and inputs it to the control circuit 32. As a result, the fire signal generating circuit 33 is configured to function and issue an alarm.

[0005]

By the way, in the above flame detector based on the detection of ultraviolet rays, unlike the heat source in the heat detector and the smoke source in the smoke detector, the ultraviolet ray source that emits ultraviolet rays is, for example, a mercury lamp in addition to the flame at the time of fire. , Halogen lamps, suns, germicidal lamps, fluorescent lamps, and many other commonly used lamps. Therefore, the flame detector based on the detection of ultraviolet rays is apt to malfunction due to an ultraviolet ray source other than the flame, and in fact, non-fire alarms due to ultraviolet rays other than the flame are often issued. Therefore, when a flame detector based on ultraviolet ray detection is installed, the sensitivity is lowered after installation and the target ultraviolet ray source is moved to prevent the non-fire alarm. In such a situation, when installing a flame detector that uses ultraviolet rays,
It is necessary to measure the ultraviolet rays other than the flame around the sensor installation location in advance and adjust the sensitivity of the flame sensor, or move the ultraviolet ray source. However, an optical ultraviolet ray measuring device such as a monochromator is for research and development, and it is large and cumbersome, and it is not only laborious to measure but also expensive, so it can not be used at all in places where flame detectors are installed. Absent. For these reasons, the advent of an inexpensive device that can easily detect ultraviolet rays is desired.

The present invention has been made to meet the above demands, and an object thereof is to provide an ultraviolet ray detector using an ultraviolet ray detecting tube (UV tron) that can be easily operated on site and is inexpensive.

[0007]

To achieve the above object, an ultraviolet detector according to the present invention comprises a power source, a high voltage drive circuit for boosting and rectifying a DC voltage applied from the power source, and outputting the DC voltage. A smoothing capacitor that smoothes the DC voltage of the high-voltage drive circuit, an ultraviolet ray detection tube to which the voltage of the smoothing capacitor is applied, and a discharge voltage due to the incidence of ultraviolet rays on the ultraviolet ray detection tube are detected to discharge for a predetermined time. It comprises a discriminating circuit for computing the number of times of voltage, and a display circuit for digitally displaying the number of times of the pulse voltage per predetermined time period computed by the discriminating circuit.

[0008]

The direct current of a direct current power source such as a battery is boosted and rectified by a high voltage drive circuit to obtain high voltage direct current, which is applied to an ultraviolet ray detecting tube. When ultraviolet rays enter the ultraviolet detector tube to which a high DC voltage is applied, the ultraviolet detector tube starts discharging and generates a pulse voltage proportional to the amount of ultraviolet rays. The number of pulses is calculated by the discriminating circuit, the number of pulses per predetermined time is output to the display circuit, and the display circuit displays this.

[0009]

【Example】

Embodiment 1 FIG. 1 is a circuit diagram of an ultraviolet detector showing an embodiment of the present invention. UV detection pipe 1 is made of UV Tron in FIG, 2 is an oscillation circuit, a transformer, it includes a like rectifier diode, high voltage driving circuit for supplying a direct current high voltage required for UV detection tube, 3 is a capacitor C _1, Reference numeral 4 is a resistor R ₁ , reference numeral 5 is a discrimination circuit composed of a microcomputer chip, 6a and 6b are switches for selecting sensitivity of the discrimination circuit 5, and 7 is a display circuit.
Digital display board 8 and light emitting diodes D ₁ 9 and D ₂ 1
0, resistors R ₂ 11, R ₃ 12 and light emitting element drive circuit 1
3 and a lighting indicator. Reference numeral 14 is a constant voltage circuit, 15 is a battery, and 16 is a switch. The ultraviolet detector according to the present invention is provided with the above-mentioned components, and each component is portable and compactly housed in a casing, and the ultraviolet detection tube 1 is arranged so that ultraviolet rays in the atmosphere can enter, and the display panel 8
Or a light emitting diode D ₁ 9, D ₂ 10 is constructed by arranging the visible.

Next, the operation will be described. Bring the above-mentioned ultraviolet detector to the place where the amount of ultraviolet rays is detected, and place the ultraviolet detector in the atmosphere. When ultraviolet rays are incident on the ultraviolet ray detection tube 1, the ultraviolet ray detection tube 1 starts discharging, and the discharge current is mainly due to the electric charge charged in the capacitor 3 to the resistance R.
Electricity instantaneously flows to ₁ and a thin pulse voltage is generated.
When the charge on the capacitor C ₁₃ decreases, the discharge is suspended. The resistor R ₁₄ is for taking out the discharge current in the form of voltage pulse. The determination circuit 5 calculates the number of discharges of the input pulse voltage per predetermined time and outputs it to the display circuit 7 as the number of pulses per predetermined time. The display circuit 7 digitally displays the number of pulses per predetermined time on the display board 8. The user of the UV detector can use this display panel 8
It is possible to know the intensity of ambient ultraviolet rays by the number. The light emitting diodes D ₁ 9 and D ₂ 10 emit light of different colors, and the light emitting diode D ₁ 9 emits yellow light when the measured amount of ultraviolet rays is more than the amount that affects the ultraviolet ray detection of the flame detector. diode D ₂ 10 is if configured to emit green when: the amount, which is the presence or absence of influence of ambient UV dose conveniently easily visible can. The switch 6 is for adjusting the sensitivity of the discriminating circuit 5 according to the intensity of the ultraviolet rays, and the sensitivity is selected while checking the intensity of the incident ultraviolet rays with the light emitting diode D ₁ or D ₂ . In addition, instead of the battery, the power source may be provided with the input terminal of the AC adapter in the casing, or a blade may be provided in the casing so that the power can be supplied from the receiver so that it can be connected to the base of the flame detector. Good.

[0011]

The ultraviolet detector of the present invention comprises a DC power source,
A high-voltage drive circuit that boosts and rectifies the voltage of the DC power supply and outputs it, an ultraviolet ray detection tube to which the DC voltage of the high-voltage drive circuit is applied via a smoothing capacitor, and a discharge caused by the incident ultraviolet ray of the ultraviolet ray detection tube. Since it is configured to include a discriminating circuit that detects the voltage and calculates the number of discharge voltages per predetermined time, and a display circuit that digitally displays the number of pulse voltages per predetermined time calculated by the discriminating circuit, It has become possible to provide a compact, portable, and easy-to-use ultraviolet detector at low cost. As a result, when installing the flame detector, the amount of ultraviolet light at the place where the flame detector is installed is measured by this ultraviolet detector, and the sensitivity of the flame detector is adjusted in advance according to the measured value to detect It became possible to make sure that the fire alarm of the vessel was reliable.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an ultraviolet detector that is an embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional flame detector.

[Explanation of symbols]

1 ... Ultraviolet detector tube 2 ... High-voltage drive circuit 3 ... Capacitor C ₁ 4 ... Resistor R ₁ 5 ... Discrimination circuit 6 ... Switch 7 ... Display circuit 8 ... Display panel 9 ... Light emitting diode D ₁ 10 ... Light emitting diode D ₂ 11 ... Resistor R ₂ 12 ... Resistor R ₃ 13 ... Element drive circuit 14 ... Constant voltage circuit 15 ... Battery 16 ... Switch

Claims (1)

[Claims] 1. A power supply, a high-voltage drive circuit that rectifies and outputs a predetermined DC voltage after boosting a DC voltage supplied from the power supply, and a smoothing capacitor that smoothes the DC voltage of the high-voltage drive circuit. An ultraviolet ray detection tube to which the voltage of the smoothing capacitor is applied, a discrimination circuit for detecting a discharge voltage generated by incidence of ultraviolet rays on the ultraviolet ray detection tube, and calculating the number of times of the discharge voltage per predetermined time; 2. An ultraviolet detector comprising: a display circuit for digitally displaying the number of pulse voltages calculated in a predetermined time.