CN107449510B - A kind of ultraviolet light detection module - Google Patents

Abstract

The invention discloses an ultraviolet light detection module. The method is to use a plurality of ultraviolet photosensitive elements of the same type to detect ultraviolet light in the environment synchronously, and convert the detection signals output by each ultraviolet photosensitive element into corresponding pulse signals. , by detecting the time interval between the pulse signals, when the length of the time interval does not exceed the set value, an early warning signal is generated, thus indicating that each ultraviolet photosensitive element detects the presence of ultraviolet light in the environment, rather than the ultraviolet photosensitive element itself. Electrical noise triggers an impulse response that is generated indefinitely. Therefore, the present invention is applied in the case of sunlight illumination and elevated ambient temperature, which can avoid the significant reduction in the effectiveness of ultraviolet light detection caused by electronic noise triggering, which is prone to false alarms.

Description

An ultraviolet light detection module

technical field

The invention relates to the technical field of ultraviolet light detection, in particular to an ultraviolet light detection module.

Background technique

Under daily working conditions, the ultraviolet photosensitive element will generate irregular pulse responses due to electronic noise triggering, which will affect the effectiveness of ultraviolet light detection. The possibility will be greatly increased, resulting in a significant reduction in the effectiveness of ultraviolet light detection, prone to false positives. Therefore, there is a need for a technical solution that can still ensure the effectiveness of ultraviolet light detection under the conditions of sunlight illumination and elevated ambient temperature.

Contents of the invention

The purpose of the present invention is to solve the problem that in the prior art, when the ultraviolet photosensitive element is applied in the case of sunlight illumination and ambient temperature rise, the possibility of its electronic noise triggering will be greatly increased, resulting in a significant reduction in the effectiveness of ultraviolet light detection, which is easy to A technical issue that produced false positives.

In order to realize the above-mentioned purpose of the invention, the present invention provides the following technical solutions:

A kind of ultraviolet light detection module, it comprises,

At least two ultraviolet photosensitive elements of the same type are used to detect ultraviolet light in the environment;

The signal processing module is used to convert the detection signal output by each ultraviolet photosensitive element into a corresponding pulse signal;

The charge release module is used to collect the amount of charge accumulated on the cathode of each ultraviolet photosensitive element to obtain a collection signal, and under the trigger control of the enable signal, connect the cathode and anode of the corresponding ultraviolet photosensitive element to generate a discharge current to release The charge accumulated on the cathode of the ultraviolet photosensitive element;

The micro-control module is used to detect the time interval between the pulse signals. When the length of the time interval does not exceed the set value, an early warning signal is generated to prompt the detection of ultraviolet light in the environment, and according to the sampling signal, Judging whether the amount of charge accumulated on the cathode of the ultraviolet photosensitive element reaches a set threshold, if the set threshold is reached, an enable signal is output to the charge release module;

The voltage supply module is used to provide working voltage for each ultraviolet photosensitive element and the micro control module.

According to a specific implementation, in the ultraviolet detection module of the present invention, the micro-control module is used to perform A/D conversion on the waveform data of the pulse signal to obtain corresponding waveform data, and calculate the The intensity value, start time and duration of the UV signal.

Further, in the ultraviolet light detection module of the present invention, the micro-control module is connected to the output interface circuit, and outputs the warning signal, the intensity value of the ultraviolet light signal, the start time and the duration through the output interface circuit. Output data to external devices, or obtain configuration information transmitted by external devices.

According to a specific implementation, in the ultraviolet light detection module of the present invention, the signal processing module includes,

A filtering circuit, used for filtering the detection signals output by each ultraviolet photosensitive element;

An amplification circuit is used to amplify the filtered detection signal;

The shaping circuit is used for shaping the amplified detection signal to obtain a corresponding pulse signal.

According to a specific embodiment, in the ultraviolet light detection module of the present invention, the charge release module includes at least two charge release circuits, each of the charge release circuits corresponds to an ultraviolet photosensitive element, and the charge The release circuit consists of,

A sampling resistor, one end of which is grounded, and one end connected to the cathode end of an ultraviolet photosensitive element;

an amplifying circuit, configured to amplify the voltage on the sampling resistor to obtain a sampling signal;

The switch circuit is used to connect the cathode and anode of the ultraviolet photosensitive element under the trigger control of the enabling signal, and generate a discharge current to release the charges accumulated on the cathode of the ultraviolet photosensitive element.

Further, in the ultraviolet light detection module of the present invention, the micro-control module is respectively connected to the amplification circuits of each of the charge release circuits, the sampling data is obtained by performing A/D conversion on the sampling signal, and it is judged whether the sampling data reaches The threshold is set, and when the sampled data reaches the set threshold, the enable signal is output to the switch circuit of the corresponding charge release circuit.

Compared with prior art, the beneficial effect of the present invention:

1. The present invention uses a plurality of identical ultraviolet photosensitive elements to detect ultraviolet light in the environment synchronously, after converting the detection signals output by each ultraviolet photosensitive element into corresponding pulse signals, by detecting the time interval between pulse signals, when When the length of the time interval does not exceed the set value, an early warning signal is generated, thereby indicating that each ultraviolet photosensitive element detects the presence of ultraviolet light in the environment, rather than the impulse response generated by the ultraviolet photosensitive element itself due to electronic noise triggering from time to time. Therefore, the present invention is applied in the case of sunlight illumination and rising ambient temperature, which can avoid the significant reduction in the effectiveness of ultraviolet light detection caused by electronic noise triggering, which is prone to false alarms.

2. The present invention collects the amount of charge accumulated on the cathode of each ultraviolet photosensitive element through the charge release module to obtain a collection signal, and the micro-control module judges whether the amount of charge accumulated on the cathode of the ultraviolet photosensitive element reaches the set threshold according to the sampling signal. Set the threshold, then output the enable signal to the charge release module, and the charge release module, under the trigger control of the enable signal, connects the cathode and anode of the corresponding ultraviolet photosensitive element to generate a discharge current to release the accumulated energy on the cathode of the ultraviolet photosensitive element. charge. Therefore, the present invention can release the charge accumulated on the ultraviolet photosensitive element when the charge of the ultraviolet photosensitive element is accumulated to a certain extent, thereby avoiding the charge accumulation phenomenon due to the ultraviolet photosensitive element, increasing the probability of triggering by the background noise of the ultraviolet photosensitive element, and making the The triggering of the background noise of the UV photosensitive element is more likely to affect the UV detection results.

Description of drawings:

Fig. 1 is the structural representation of the first embodiment of the present invention;

Fig. 2 is the structural representation of the second embodiment of the present invention;

Fig. 3 is a schematic structural view of the charge releasing circuit of the present invention;

FIG. 4 is a schematic structural diagram of an embodiment of the charge releasing circuit of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with test examples and specific embodiments. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

In conjunction with the schematic structural view of the first embodiment of the present invention shown in Figure 1; wherein, the ultraviolet light detection module of the present invention includes two ultraviolet photosensitive elements 1 and ultraviolet photosensitive elements 2 of the same model, a voltage supply module, a signal processing module, and a charge release modules and microcontroller modules.

Wherein, the voltage supply module is respectively connected with the power terminals of the ultraviolet photosensitive element 1 and the ultraviolet photosensitive element 2, and provides corresponding working voltage. The signal processing module is respectively connected to the output terminals of the ultraviolet photosensitive element 1 and the ultraviolet photosensitive element 2. Since the ultraviolet photosensitive element detects ultraviolet light or triggers an impulse response due to electronic noise, the detection signal is output from the output terminal. Since the detection signal is The weak current signal needs to be processed by the signal processing module and converted into a pulse signal, and then further analyzed and processed by the micro control module.

The micro-control module detects the time interval between the pulse signals, and when the length of the time interval does not exceed the set value, an early warning signal is generated to prompt the detection of ultraviolet light in the environment. Its working principle is as follows: the pulse response of the ultraviolet photosensitive element triggered by electronic noise is irregular and belongs to random events. Then, the situation that two ultraviolet photosensitive elements generate impulse responses due to electronic noise triggering at the same time is a small probability event compared with the situation that two ultraviolet photosensitive elements simultaneously detect ultraviolet light and generate impulse responses. Moreover, two identical ultraviolet photosensitive elements generate impulse responses due to electronic noise triggering, and the time interval is usually on the order of seconds, and two identical ultraviolet photosensitive elements are due to the stability of their technical parameters and the consistency of detection conditions. The two detect ultraviolet light and generate an impulse response, and the time interval is usually on the order of milliseconds or even microseconds. Therefore, the micro control module of the present invention detects the time interval between the pulse signals and sets a reasonable time value. Then, even if the application is in the case of sunlight and elevated ambient temperature, false alarms due to electronic noise triggering can be eliminated, thereby improving the effectiveness of UV light detection.

Moreover, the charge release module in the ultraviolet light detection module of the present invention obtains the collection signal by collecting the charge accumulated on the cathode of each ultraviolet photosensitive element. According to the sampling signal, the micro-control module judges whether the charge accumulated on the cathode of the ultraviolet photosensitive element reaches the set threshold, and if it reaches the set threshold, it outputs an enable signal to the charge release module, and the charge release module is triggered by the enable signal. , connect the cathode and anode of the corresponding ultraviolet photosensitive element to generate a discharge current to release the charge accumulated on the cathode of the ultraviolet photosensitive element.

In conjunction with the structural representation of the second embodiment of the present invention shown in Fig. 2; In this embodiment, the micro-control module is connected with the output interface circuit, and the micro-control module obtains the corresponding Waveform data, and according to the waveform data, calculate the intensity value, start time and duration of the ultraviolet light signal. Then, the micro-control module is connected with the external device through the output interface circuit, and outputs the data of the early warning signal, the intensity value of the ultraviolet light signal, the start time and the duration to the external device, or obtains the data transmitted by the external device through the output interface circuit. configuration information.

During implementation, the output interface circuit adopted by the present invention is an optocoupler interface circuit and/or an isolated RS485 interface circuit. The optocoupler interface circuit adopts OC gate output, which is convenient for the connection of the external control circuit, and also avoids the electronic noise interference between the external circuit and the micro control module. And the isolated RS485 interface circuit can realize the communication between the micro control module and the external detection or control equipment.

The ultraviolet photosensitive element in the ultraviolet light detection module of the present invention adopts sun-blind ultraviolet photosensitive element, and its detection band is 185～260nm, and its operating voltage is 280～350VDC, and its setting error＜=±0.5VDC, meanwhile, the ultraviolet light of the present invention The working voltage of the micro-control module in the detection module is 24VDC, therefore, the voltage supply module provides working voltages of 280-350VDC and 24VDC to the ultraviolet photosensitive element and the micro-control module respectively.

Specifically, the signal processing module in the ultraviolet light detection module of the present invention includes a filter circuit, an amplification circuit and a shaping circuit. Wherein, the filtering circuit is used for filtering the detection signals output by each ultraviolet photosensitive element. The amplifying circuit is used for amplifying the filtered detection signal. The shaping circuit is used for shaping the amplified detection signal to obtain the corresponding pulse signal. The above are all conventional technical means in the art, and will not be repeated here.

A schematic structural diagram of the charge release circuit of the present invention shown in FIG. 3 ; wherein the charge release circuit includes a sampling resistor Rc, an amplifier circuit and a switch circuit.

Wherein, one end of the sampling resistor Rc is grounded, and the other end is connected to the cathode end of the ultraviolet photosensitive tube. Once the charge accumulation occurs on the cathode of the ultraviolet photosensitive tube, a potential difference will be formed between the sampling resistors, that is, a voltage will be formed. The amplifying circuit obtains a sampling signal by amplifying the voltage on the sampling resistor Rc, and the amplifying circuit outputs the obtained sampling signal to the micro control module. The micro-control module judges whether the charge accumulated on the cathode of the ultraviolet photosensitive tube reaches a set threshold according to the sampling signal, and outputs an enable signal to the switch circuit if it reaches the set threshold. Under the trigger control of the enable signal, the switch circuit connects the cathode terminal and the anode terminal of the ultraviolet photosensitive tube, so that the cathode and anode of the ultraviolet photosensitive tube generate a discharge current, thereby releasing the charge accumulated on the cathode of the ultraviolet photosensitive tube.

The charge releasing module in the present invention includes at least two charge releasing circuits, and each charge releasing circuit corresponds to an ultraviolet photosensitive element, so as to independently detect and release the charges accumulated on the cathode of each ultraviolet photosensitive element.

In conjunction with the schematic structural diagram of an embodiment of the charge release circuit of the present invention shown in FIG. 4 ; wherein, the micro-control module obtains sampled data by performing A/D conversion on the sampled signal, and then judges whether the sampled data reaches a set threshold, Once the sampling data reaches the set threshold, the micro-control module outputs an enable signal to the switch circuit, so that the switch circuit connects the cathode terminal and the anode terminal of the ultraviolet photosensitive tube, so that a discharge is generated between the cathode and the anode of the ultraviolet photosensitive tube Electric current releases the charge accumulated on the cathode of the ultraviolet photosensitive tube.

Wherein, the amplifying circuit includes an operational amplifier U1, a resistor R1 and a resistor R2. Wherein, one input end of the operational amplifier U1 is grounded, the other input end is connected to one end of the resistor R1 and the resistor R2 respectively, the other end of the resistor R2 is connected to the output end of the operational amplifier U1, and the other end of the resistor R1 is connected to the sampling resistor Rc, the output terminal of the operational amplifier U1 outputs the sampling signal.

The switch circuit includes a transistor Q1, a resistor R3 and a resistor R4; wherein, one end of the resistor R3 is used as the input end of the enabling signal, the other end is connected to the base of the transistor Q1, one end of the resistor R4 is connected to the voltage source VCC, and the other end It is connected to the source of the triode Q1, and the emitter of the triode Q1 is connected to the grounded end of the sampling resistor Rc.

When the enable signal output by the micro control module reaches the base of the transistor Q1 through the resistor R2, the base of the transistor Q1 generates a high level, thereby turning on the transistor Q1. After the triode Q1 is turned on, the cathode terminal and the anode terminal of the ultraviolet photosensitive tube are connected, so that a discharge current is generated between the cathode and the anode of the ultraviolet photosensitive tube, and the discharge current flows into the ground terminal through the triode Q1.

Claims (6)

1. a kind of ultraviolet light detection module, which is characterized in that including,

The uv-sensitive component of at least two same models, for detecting the ultraviolet light in local environment；

Signal processing module, the detectable signal for being exported each uv-sensitive component are converted to corresponding pulse signal；

Charge release module for acquiring the quantity of electric charge accumulated on each uv-sensitive component cathode, and obtains sampled signal, with And under the triggering control of enable signal, the cathode and anode of corresponding uv-sensitive component is connected, discharge current is generated, with release The charge accumulated on uv-sensitive component cathode；

Micro-control module, for detecting the time interval between pulse signal, when of length no more than setting value at having time interval, Pre-warning signal is generated, is detected with prompt and occurs ultraviolet light in local environment, and according to the sampled signal, judge ultraviolet light Whether the quantity of electric charge accumulated on quick element cathode reaches given threshold, if reaching the given threshold, export enable signal to The charge release module；

Voltage supplying module, for providing operating voltage for each uv-sensitive component and the micro-control module.

2. ultraviolet light detection module as described in claim 1, which is characterized in that the micro-control module, for believing pulse Number Wave data carry out A/D conversion, obtain corresponding Wave data, and according to Wave data, calculate ultraviolet signal Intensity value, initial time and duration.

3. ultraviolet light detection module as claimed in claim 2, which is characterized in that the micro-control module and output interface circuit Connection, and the pre-warning signal, the intensity value of ultraviolet signal, initial time are exported by the output interface circuit and continued The data of time are exported to external equipment, or obtain the configuration information of external equipment transmission.

4. ultraviolet light detection module as described in claim 1, which is characterized in that the signal processing module includes,

Filter circuit, the detectable signal for being exported to each uv-sensitive component are filtered；

Amplifying circuit, for amplifying processing to the detectable signal after being filtered；

Shaping circuit for carrying out Shape correction to the detectable signal after enhanced processing, and obtains corresponding pulse signal.

5. ultraviolet light detection module as described in claim 1, which is characterized in that the charge release module includes at least two Charge release circuit, each charge release circuit is corresponding with a uv-sensitive component, also, charge release electricity Road includes,

Sampling resistor, one end ground connection, one end is connect with the cathode terminal of a uv-sensitive component；

Amplifying circuit for amplifying to the voltage on the sampling resistor, and obtains sampled signal；

Switching circuit, for connecting the cathode and anode of uv-sensitive component, and produce under the triggering of enable signal control Raw discharge current, to discharge the charge accumulated on the uv-sensitive component cathode.

6. ultraviolet light detection module as claimed in claim 5, which is characterized in that the micro-control module respectively with it is each described The amplifying circuit of charge release circuit connects, and obtains sampled data and carrying out A/D conversion to sampled signal, and described in judgement Whether sampled data reaches the given threshold, and when the sampled data reaches the given threshold, exports described enabled Signal to corresponding charge release circuit switching circuit.