CN103398775A - Light signal acquisition system based on photodiode - Google Patents

Abstract

The invention discloses a light signal acquisition system based on a photodiode, which comprises a photoelectric conversion circuit, an analog circuit, an AD (Analog to Digital) conversion and storage part and a display part, wherein the photoelectric conversion circuit is connected with the analog circuit, the AD conversion and storage part and the display part sequentially. The light signal acquisition system based on the photodiode is a miniaturization system gathering the photoelectric conversion circuit, the analog circuit, the AD conversion and storage part and the display part, the photodiode in the photoelectric conversion circuit serves as a light signal detection element, infrared weak light detection and on-off control are performed by using the characteristics of high sensitivity, short response time, spectral response and wide measured light intensity range and the like of the photodiode, and an influence of natural light is eliminated by a low-pass analog filter in the analog circuit, so that the testing accuracy can be improved, and an application range is expanded.

Description

A kind of system of light signal collection based on photodiode

Technical field

The invention belongs to the light signal collection technical field, particularly relate to a kind of system of light signal collection based on photodiode.

Background technology

In productive life, a lot of phenomenons all are accompanied by luminescence phenomenon, such as daylight, burning, explosion, nuclear radiation etc., and the detection by daylight can provide important foundation for research of agricultural science; Can be effectively pre-anti-pollution and take safeguard measure by the detection to the nuclear radiation energy.But, at present there is the light source measurement narrow range in the collection of light signal, sensitivity is poor, therefore the problem such as the filtering not of the impurity light source except measurement light source.

Summary of the invention

, in order to address the above problem, the object of the present invention is to provide a kind of system of light signal collection based on photodiode.

In order to achieve the above object, the system of the light signal collection based on photodiode provided by the invention comprises: photoelectric switching circuit, mimic channel, AD conversion and storage part and display part; Wherein: photoelectric switching circuit mainly is comprised of photoelectric sensor, and it is connected with mimic channel, is used for receiving optical signals, and converts it into electric signal;

Mimic channel comprises analogue filter circuit and amplifying circuit, and it is connected with AD conversion and storage part, is used for photoelectric switching circuit output terminal electric signal is carried out shaping filter and amplification, generates and meets the voltage signal that the AD conversion requires;

AD conversion and storage part are comprised of analog to digital converter and storer, and it is connected with display part, are used for the analog voltage signal of mimic channel output is carried out analog to digital conversion, and the data that then will obtain are stored;

Display part consists of digital indicator, is used for showing the temperature information that collects.

The photoelectric sensor of described photoelectric switching circuit consists of photodiode.

Filtering circuit in described mimic channel adopts low-pass analog filter.

Light signal collection based on photodiode system provided by the invention is the micro mation system that photoelectric switching circuit, mimic channel, AD conversion and storage part and display part are gathered together, photodiode in the employing photoelectric switching circuit is as the optical signal detection element, utilize that it is highly sensitive, the response time is short, the characteristics such as spectral response and the strong wide ranges of institute's photometry carry out infrared Dim light measurement and switch is controlled, utilize simultaneously the impact of the low-pass analog filter eliminating natural light in mimic channel, thereby can improve measuring accuracy, therefore enlarge range of application.

Description of drawings

Fig. 1 is the structural representation of the system of the light signal collection based on photodiode provided by the invention.

Embodiment

Below in conjunction with the drawings and specific embodiments, the system of the light signal collection based on photodiode provided by the invention is elaborated.

As shown in Figure 1, the system of the light signal collection based on photodiode provided by the invention comprises: photoelectric switching circuit 1, mimic channel 2, AD conversion and storage part 3 and display part 4; Wherein: photoelectric switching circuit 1 mainly is comprised of photoelectric sensor, and it is connected with mimic channel 2, is used for receiving optical signals 5, and converts it into electric signal;

Mimic channel 2 comprises analogue filter circuit and amplifying circuit, and it is connected with AD conversion and storage part 3, is used for photoelectric switching circuit 1 output terminal electric signal is carried out shaping filter and amplification, generates and meets the voltage signal that the AD conversion requires;

AD conversion and storage part 3 are comprised of analog to digital converter and storer, and it is connected with display part 4, are used for the analog voltage signal of mimic channel 2 outputs is carried out analog to digital conversion, and the data that then will obtain are stored;

Display part 4 consists of digital indicator, is used for showing the temperature information that collects.

The photoelectric sensor of described photoelectric switching circuit 1 consists of photodiode, because the advantage such as that photodiode has is highly sensitive, the response time is short, spectral response and the strong wide ranges of institute's photometry is mainly used in infrared Dim light measurement and switch control aspect.

Filtering circuit in described mimic channel 2 adopts low-pass analog filter, with the interference of filtering natural light.

Amplifying circuit in described mimic channel 2 adopts logarithmic amplifier MAX4206, MAX4206 is a typical direct current logarithmic amplifier, but processing variation is direct current signal slowly, can process five orders of magnitude dynamic range (1nA-10mA), its transport function as the formula (1):

$\mathrm{VOUT}=\frac{\mathrm{kT}}{q}\·\ln \left(\frac{I_{\mathrm{IN}}}{I_{\mathrm{REF}}}\right)=\frac{\mathrm{kT}}{q}\·\ln \left(10\right)\·{\log }_{10}\left(\frac{I_{\mathrm{IN}}}{I_{\mathrm{REF}}}\right)=K\·{\log }_{10}\left(\frac{I_{\mathrm{IN}}}{I_{\mathrm{REF}}}\right)---\left(1\right)$

K=1.381x10-23J/ ° of K, T=absolute temperature (° K), q=1.602x10-19 ℃

K is scale factor in formula, I _REF, for reference voltage, in a lot of optical sensors, adopt MAX4206 to measure the attenuation degree of light signal.

Described AD conversion and storage part 3 are by the chip microcontroller with AD converter.

The principle of work of the system of the light signal collection based on photodiode provided by the invention is as follows: photoelectric switching circuit 1 absorbs optical radiation, and its light signal that will obtain is converted into voltage signal; Because the output of photodiode is current signal, convenient for subsequent treatment, at first to convert thereof into voltage signal,, by the parameter in contrast chip data, select the mode of operation of bias voltage; Need to get rid of the interference of natural light in the environment of some test, can adopt filter plate under general environment, but the installation and maintenance of filter plate has certain restriction to the profile of proving installation, because natural light is very low through the current signal frequency of conversion output, therefore be provided with low-pass filter in mimic channel 2, be used for the interference of filtering natural light; Core component in mimic channel 2 is logarithmic amplifier, output signal after amplification filtering is processed, convert digital quantity to by the analog to digital converter in AD conversion and storage part 3, then store in storer, the light signal information exchange that will collect is finally crossed display part 4 and is shown.

From the result of experiment, this test macro has certain feasibility, can capture more exactly the whole change procedure of light signal, both can be used as independent light signal collection circuit, also can be used as the trigger switch of some proving installation.

Claims (3)

1. system of the light signal collection based on photodiode, it is characterized in that: described light signal collection system comprises: photoelectric switching circuit (1), mimic channel (2), AD conversion and storage part (3) and display part (4); Wherein: photoelectric switching circuit (1) mainly is comprised of photoelectric sensor, and it is connected with mimic channel (2), is used for receiving optical signals (5), and converts it into electric signal;

Mimic channel (2) comprises analogue filter circuit and amplifying circuit, and it is connected with AD conversion and storage part (3), is used for photoelectric switching circuit (1) output terminal electric signal is carried out shaping filter and amplification, generates and meets the voltage signal that the AD conversion requires;

AD conversion and storage part (3) are comprised of analog to digital converter and storer, and it is connected with display part (4), are used for the analog voltage signal of mimic channel (2) output is carried out analog to digital conversion, and the data that then will obtain are stored;

Display part (4) consists of digital indicator, is used for showing the temperature information that collects.

2. light signal collection system according to claim 1, it is characterized in that: the photoelectric sensor of described photoelectric switching circuit (1) consists of photodiode.

3. light signal collection system according to claim 1, is characterized in that: the filtering circuit employing low-pass analog filter in described mimic channel (2).

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