CN101799497B - Thunder alarm instrument - Google Patents

Abstract

The invention discloses a lightning alarm device, comprising: an electric field sensor, a lightning signal processing circuit and an alarm; the electric field sensor generates a time-varying current by induction according to the time-varying electromagnetic field caused by lightning when the lightning is active, and the The time-varying current is sent to the lightning signal processing circuit; the lightning signal processing circuit processes the input time-varying current signal, finally converts the time-varying current signal into a digital signal, and analyzes, identifies and judges the value and number density of the digital signal , if the value and number density reach the set warning line in the set period, the alarm will be notified to send out an alarm signal. The lightning alarm device of the present invention has the advantages of low cost, long working life, low power consumption, convenient operation and maintenance, large monitoring range, and can work in various climatic environments.

Description

A lightning alarm

technical field

The invention relates to the field of lightning alarms, in particular to a lightning alarm device. the

Background technique

With the frequency and severity of lightning disasters, more and more attention has been paid to lightning protection and early warning in various places. At present, lightning monitoring and forecasting generally use electric field mills, which are also called atmospheric electric field mills, which are based on the electrostatic effect of lightning and measure the magnitude of the electrostatic field generated during the electrification process of thunderstorm clouds. The advantage of this instrument is that it can monitor the whole process of lightning occurrence, development, and dissipation. Its disadvantage is that it can only monitor lightning activities within a radius of 8-9km from the measuring point. The rotating electric field meter is divided into two parts: the outdoor probe and the indoor main unit. The probe sensor needs to be driven by a motor to rotate. The probe output has two channels: the electric field signal channel and the reference signal channel generated by photoelectricity. The indoor main board also includes (as shown in Figure 1 ) Phase adjustment circuit, integrator, synchronous detection circuit, bidirectional comparator, beat oscillator, etc., are relatively complex, and the power consumption is about 30 watts. the

The patent number is ZL03160053.0, which discloses a constant-speed rotating flip-chip electric field meter. It is undoubtedly the leader in the current domestic similar lightning monitoring products in terms of performance and use effect. The Municipal Meteorological Observatory conducted a comparative test of the atmospheric electric field meter (rotary electric field meter) produced by 10 units at home and abroad (including 3 foreign countries in the United States, France and Spain, and 2 units affiliated to the China Meteorological Administration) for a period of nearly 4 months. , 'Constant-speed rotating flip-chip electric field meter' ranks first. However, because the monitoring is the electrostatic effect of lightning, the monitoring range is small, and because of the rotating part, the service life is correspondingly shorter than that of the completely static type. Especially for the vast rural areas and remote mountainous areas, the structure is still a bit complicated and the power consumption is relatively large. , The price is also a bit high. the

Contents of the invention

In order to overcome the shortcomings of the rotating electric field meter for monitoring the electrostatic effect of lightning, the range of action is small (the radius of the measuring point is 8-9km), the structure is relatively complex, the power consumption is large, the price is high, and regular maintenance is required. A lightning alarm device provided by the present invention is based on the time-varying electromagnetic field effect generated by lightning, which can timely send lightning development information and send out lightning alarm signals, and has low cost, long working life, low power consumption, convenient operation and maintenance, and a wide monitoring range. It is suitable for use in vast rural areas and remote mountainous areas that lack capital and technology. the

In order to achieve the above purpose, the present invention provides a lightning alarm device, comprising: an electric field sensor, a lightning signal processing circuit and an alarm. the

The electric field sensor 1 adopts a flat plate structure and is placed horizontally above the probe. Based on the principle that the conductor induces charges in the electric field, and according to the time-varying electromagnetic field caused by lightning during lightning activity, a time-varying current is induced and sent to the sensor. into the lightning signal processing circuit. the

The lightning signal processing circuit is used for processing the input time-varying current signal, finally converting the time-varying current signal into a digital signal, and analyzing, identifying and judging the numerical value and number density of the digital signal. This analysis, identification, and judgment are Based on the background of sunny and cloudy days without lightning and a large amount of observation data in the comparative test with the rotary ground atmospheric electric field meter, compare the different phenomena when there is lightning and no lightning, and select the threshold level of the warning line and the data Size, select a certain period of time to avoid false alarms caused by sudden large false signals from people and machines, and select an appropriate threshold level to prevent false alarms. If the numerical value and number density of the digital signal reach the set warning line in the set period, the notification alarm will send out an alarm signal. the

The alarm is used for sending out an alarm signal. the

Wherein, the lightning alarm device further includes: a probe, a base 12 and a tubular support 10 . the

The electric field sensor is arranged on the outside of the probe, and is connected to the lightning signal processing circuit through the signal introduction part 5; the signal introduction part 5 is nested and fixed in the central hole of the shell, and is insulated from the shell through the insulator 3; the lightning The signal processing circuit is fully encapsulated in the probe. the

One end of the tubular support 10 is fixed to the probe, and the other end is fixed to the base 12; the tubular support 10 communicates with the probe and the base, and the signal transmission cable and power cord are directly drawn from the probe through the tubular support 10 to the base 12. the

Wherein, the lightning signal processing circuit includes:

A current/voltage converter is used to convert the time-varying current into a first time-varying voltage. the

A high-pass filter is used to remove low-frequency spurious signals larger than useful signals in the first time-varying voltage, so as to ensure that the frequency band of the signal to be tested has better amplification characteristics and higher gain in the amplification of the subsequent stage. the

A voltage amplifier is used to amplify the first time-varying voltage passing through the high-pass filter into a second time-varying voltage, which is then isolated and sent to the band-pass filter. the

A pass filter is used to obtain a signal of a desired frequency band from the second time-varying voltage and send the signal to a peak detector. the

A peak detector is used to detect the peak signal of the input signal and send the peak signal to the analog/digital converter. the

An analog/digital converter for converting the peak signal into a digital signal. the

A data processing and control circuit, the control circuit is used to control the acquisition time and rate of the analog/digital converter, access data, set alarm parameters and self-inspection; the data processing circuit is used to analyze and identify digital signals, judge, if When the numerical value and number density reach the set warning line in the set period of time, the alarm will be notified to send an alarm signal; the alarm parameters include: warning line data, alarm category, and duration. the

Wherein, the probe comprises: a cylindrical shell 8 with a hole in the bottom surface, a shell cover 2 with a central hole; the shell cover 2 is set and fixed on the shell 8; the cylindrical shell 8 and the tubular support 10 is fixed by the probe holder connector 9. the

Wherein, the shell cover 2, the cylindrical shell 8 and the tubular support 10 are made of stainless steel (No. 304 stainless steel), so as to prevent the salt spray from rusting in coastal areas and affect the life of the instrument. the

Wherein, the lightning alarm device can also include a display, which is connected with the lightning signal processing circuit through a signal transmission cable, and is used to display the lightning development situation (blank, blue, orange, red) and lightning alarm category (orange, orange, red) in the monitored area. red) signal. White means that no signal is detected above the threshold level, blue means that the currently detected signal is an interference signal, orange means 'beware of lightning', and red means 'thunder is coming soon'. the

Wherein, the alarm is a voice alarm for two situations of 'attention to lightning' and 'thunder is coming' and its corresponding flashing yellow and red light alarms. the

Wherein, the plug and socket of the alarm signal transmission cable of the lightning alarm instrument and the instrument power cord are designed to be connected inside the instrument, and the alarm signal transmission cable and the instrument power cord are drawn out from the base through the inner cavity of the tubular bracket, so that the instrument can work normally in heavy rain and windy weather. work and avoid casual damage by personnel. the

The advantages of the present invention are:

1. The principle of the lightning alarm provided by the present invention is the same as that of the traditional lightning alarm-rotary electric field mill (Electric field mill), all of which use conductors to induce charges in the electric field. The difference is: the lightning alarm instrument provided by the present invention monitors the time-varying electromagnetic field generated by lightning, so the monitoring range is large, and it can monitor the occurrence of lightning from the monitoring point to the 50km area, while the lightning alarm monitored by the rotary atmospheric electric field instrument The electrostatic effect generated, the monitoring range is only the possible occurrence of lightning within the range of 8-9km. the

2. The lightning alarm provided by the present invention has no rotating parts, simple structure, convenient maintenance and long working life. the

3. The lightning alarm device provided by the present invention is the lowest price of similar products, which is 1/4 of the commonly used rotary atmospheric electric field meter. It is the most convenient to install and use, and is very suitable for use in vast rural areas and remote mountainous areas. the

4. The probe and the signal processing circuit of the present invention are organically combined, small in size and light in weight; and except for the electric field sensor, there is no exposed electrical connector, and the alarm signal transmission cable and the instrument power cord connection plug and socket are all hidden in the instrument. Inside the casing, it can work in various climates and avoid the influence of human factors to a certain extent; the power consumption is low (about 2 watts), and it is convenient to use solar energy, storage batteries and commercial power. the

5. The combined use of the lightning alarm instrument provided by the present invention and the rotating electric field instrument can constitute the lightning monitoring equipment with the lowest price in the key defense area of lightning, which can monitor the electrostatic effect produced during the formation of thunderstorm clouds over the measuring point, and can By monitoring the time-varying electromagnetic field generated by lightning over tens of kilometers away, it is possible to monitor the occurrence of lightning within thousands of square kilometers. the

Description of drawings

Fig. 1 is the circuit block diagram of prior art rotary atmospheric electric field instrument;

Fig. 2 is a structural diagram of a lightning alarm device according to a specific embodiment of the present invention;

Fig. 3 is the circuit block diagram of lightning alarm instrument of the present invention;

Fig. 4 is the comparative experiment curve of the lightning alarm instrument of the present invention and the rotary atmospheric electric field instrument. the

Reference logo

1. Sensor 2. Housing cover 3. Insulator

4. Fixed nut 5. Signal lead-in piece 6. Circuit board

7. Circuit board 8. Shell 9. Probe bracket connector

10. Tubular bracket 11. Connector between bracket and base 12. Base

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments and accompanying drawings. the

The lightning alarm device of this embodiment, as shown in FIG. 2 , includes: an electric field sensor 1 , a lightning signal processing circuit, a probe, a base 12 and a tubular support 10 . the

The electric field sensor 1 adopts a flat plate structure, is placed horizontally above the probe, and is connected to the lightning signal processing circuit through the signal introduction part 5; Insulated from the shell; the insulator 3 is nested and fixed at the center of the shell cover through the fixing nut 4, and the lightning signal processing circuit boards 6 and 7 are packaged in the probe shell. the

The probe includes: a cylindrical shell 8 and a shell cover 2 with a central hole; the shell cover 2 is sleeved and fixed on the shell 8 . the

One end of the tubular bracket 10 is fixed to the probe through the probe bracket connector 9, and the other end is fixed to the base 12 through the bracket and base connector 11; Signal transmission cables and power cords for circuit connections. the

The shell cover 2, the cylindrical shell 8 and the bracket 10 are made of No. 304 stainless steel. the

The lightning signal processing circuit, as shown in Figure 3, includes: a current/voltage converter, a high-pass filter, a voltage amplifier, a follower, a band-pass filter, a peak detector, an isolator, a An analog/digital converter for converting the peak signal into a digital signal, a data processing and control circuit, an audible and optical alarm and a screen display. the

When there is lightning activity, the time-varying electromagnetic field caused by lightning induces a time-varying current on the electric field sensor, which is converted into a time-varying voltage by the I/V converter of the previous stage, and passes through a high-pass filter to remove low-frequency noise greater than the useful signal. Scattered signals to ensure that the frequency band of the signal to be tested has better amplification characteristics and higher gain in the amplification of the subsequent stage, and then amplified by voltage, isolated to the band-pass filter to obtain the signal of the frequency band required by the signal to be tested, peak detection The peak signal detected by the detector is isolated and sent to the digital signal obtained by A/D conversion, and the value and number density of the digital signal are analyzed, identified, and judged. If the value and number density reach the warning line for lightning, an alarm will be activated. The detector immediately issued a call sound of "Attention to lightning" and the yellow light flashed yellow light. At this time, thunder and lightning may occur, but this area has not yet occurred. Tell everyone to pay attention and be prepared. If the signal amplitude increases further and the number density increases to the warning line where thunder and lightning are about to occur, the alarm will immediately send out the call sound of "thunder and lightning is coming" and the red light will flash red light to tell everyone that thunder and lightning are coming, so avoid them quickly. If it is equipped with a computer, the "orange" and "red" curves will display two situations on the screen: "Attention to lightning" and "Lightning is coming soon". (If you are in the wild, if you don’t have time to run home, put your feet together and squat down on the spot with your hands around your knees). All lightning signal processing lines are installed in the probe, and the alarm signal can be transmitted wirelessly or wired to the place where people can feel it. The alarm signal transmission line and the power line (available solar cells) are led out from the base through the support. the

External power supply: AC (220V)/DC ±(5V-12V), battery/solar battery. the

Through more than two years and the traditional lightning alarm instrument-rotary electric field mill (Electric field mill) comparative experiment (as shown in Figure 4, the upper figure is the record curve of the rotary atmospheric electric field mill, and the lower figure is the record curve of the lightning alarm instrument of the present invention) , has a good effect on lightning monitoring and forecasting. It is characterized by low price, long working life, convenient operation and maintenance, large monitoring range, low power consumption, and can work in various weather environments, and is suitable for use in vast rural areas and remote mountainous areas. the

Claims (6)

1. A lightning alarm, comprising: an electric field sensor, a lightning signal processing circuit and an alarm; It is characterized in that, The electric field sensor (1) adopts a flat plate structure, placed horizontally above the probe, and is used to induce a time-varying current according to the time-varying electromagnetic field caused by lightning during lightning activity, and send the time-varying current to the lightning signal processing circuit; The lightning signal processing circuit is used for processing the input time-varying current signal, finally converting the time-varying current signal into a digital signal, and analyzing, identifying and judging the value and number density of the digital signal, if the value and number density are within When the set time period reaches the set warning line, the alarm will be notified to send out an alarm signal; The alarm is used to send an alarm signal; The lightning alarm device further includes: a probe, a base (12) and a tubular support (10); The electric field sensor is arranged on the outside of the probe, and is connected to the lightning signal processing circuit through the signal lead-in (5); the signal lead-in (5) is nested and fixed in the central hole of the shell, and is connected to the The shell is insulated; the lightning signal processing circuit is all encapsulated in the probe; One end of the tubular support (10) is fixed to the probe, and the other end is fixed to the base (12); the tubular support (10) communicates with the probe and the base, and the signal transmission cable and the power cord are directly passed through the tubular support (10) from the probe. Lead out in the base (12). 2. The lightning alarm device according to claim 1, wherein the lightning signal processing circuit comprises: a current/voltage converter for converting the time-varying current into a first time-varying voltage; A high-pass filter, used to remove low-frequency spurious signals greater than useful signals in the first time-varying voltage; A voltage amplifier, which is used to amplify the first time-varying voltage passing through the high-pass filter into a second time-varying voltage, which is sent to the band-pass filter after isolation; a band-pass filter for obtaining a signal of a desired frequency band from the second time-varying voltage and feeding the signal into a peak detector; A peak detector, used to detect the peak signal of the input signal, and send the peak signal to the analog/digital converter; an analog/digital converter for converting the peak signal into a digital signal; A data processing and control circuit, the control circuit is used to control the acquisition time and rate of the analog/digital converter, access data, set alarm parameters and self-inspection; the data processing circuit is used to analyze and identify digital signals, judge, if When the numerical value and number density reach the set warning line in the set time period, the alarm will be notified to send out an alarm signal; the alarm parameters include: warning line data, alarm type, and duration. 3. The lightning alarm device according to claim 1, wherein the probe comprises: a cylindrical shell (8) with a hole in the bottom surface, a casing cover (2) with a central hole; the casing cover (2) The sleeve is fixed on the housing (8); the cylindrical housing (8) and the tubular support (10) are fixed through the probe support connector (9). 4. The lightning alarm device according to claim 3, characterized in that, the housing cover (2), cylindrical housing (8) and tubular support (10) are made of stainless steel. 5. The lightning alarm device according to claim 2, characterized in that, the lightning alarm device also includes a display, which is connected with the lightning signal processing circuit through a signal transmission cable, and is used to display the lightning development situation and the lightning alarm in the monitored area category signal. 6. The lightning alarm device according to claim 1, characterized in that, the alarm is composed of an acoustic alarm and/or a light alarm.

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