Application of GT-CGOP1 photoelectric sensor design experiment instrument
GT-CGOP1 photoelectric sensor design experiment instrument
A photosensitive sensor is a sensor that converts an optical signal into an electrical signal, also called a photoelectric sensor, which can be used to detect non-electricity directly causing a change in light intensity, such as light intensity, illuminance, radiation temperature measurement, gas composition analysis, etc.; To detect other non-electric quantities that can be converted into changes in light quantity, such as part diameter, surface roughness, displacement, velocity, acceleration and shape of the object, and identification of working conditions. Photosensitive sensors are widely used in industrial automation and intelligent robots because of their non-contact, fast response and reliable performance.
The physical basis of the photosensitive sensor is the photoelectric effect, that is, the electrical properties of the photosensitive material are changed by the irradiation of light. Photoelectric effect is usually divided into two categories: external photoelectric effect and internal photoelectric effect. The external photoelectric effect refers to the phenomenon that electrons escape from the surface of the object under the illumination of light, which is also called the photoelectric emission effect. The photoelectric device based on this effect has a phototube, a photomultiplier tube and the like. The internal photoelectric effect refers to the physical phenomenon that the incident light intensity changes the conductivity of the substance, which is called the photoconductive effect. Most sensors for optoelectronic control applications, such as photoresistors, photodiodes, phototransistors, and silicon photocells, are internal photoelectric effect sensors. Of course, new photosensitive devices have emerged in recent years, such as APD avalanche photodiodes with high-speed response and amplification, semiconductor photosensors, photo-thyristors, light-guide tubes, CCD image sensors, etc., which have opened up the application of photoelectric sensors. A new page. This experiment is mainly to study the basic characteristics of four kinds of photosensitive sensors such as photoresistor, silicon photocell, photodiode and phototransistor, as well as the basic characteristics of optical fiber sensor and the basic principle of optical fiber communication.
First, the purpose of the experiment
1. Understand the basic characteristics of the photoresistor and measure its volt-ampere characteristic curve and illumination characteristic curve.
2. Understand the basic characteristics of the photodiode and measure its volt-ampere characteristics and illumination characteristics.
3. Understand the basic characteristics of the silicon photocell and measure its volt-ampere characteristic curve and illumination characteristic curve.
4. Understand the basic characteristics of the phototransistor and measure its volt-ampere characteristics and illumination characteristics.
5. Understand the basic characteristics of fiber optic sensors and the basic principles of fiber optic communication.
Second, the basic characteristics of photosensitive sensors and experimental principles
1, volt-ampere characteristics
Photosensitive sensor Under a certain incident light intensity, the relationship between the current I of the photosensitive element and the applied voltage U is called the volt-ampere characteristic of the photosensitive device. By changing the illumination, a set of volt-ampere characteristic curves can be obtained, which is an important basis for selecting electrical parameters when designing the sensor application. The volt-ampere characteristic curves of certain photoresistors, silicon photo cells, photodiodes, and phototransistors are shown in Fig. 1, Fig. 2, Fig. 3, and Fig. 4.
Figure 1 Photoresistor
Voltammetric characteristic curve
Figure 2 Silicon Photovoltaic Cell
Voltammetric characteristic curve
Figure 3 Photodiode
Voltammetric characteristic curve
Figure 4 Phototransistor
Voltammetric characteristic curve
It can be seen from the volt-ampere characteristics of the above four kinds of photosensitive devices that the photoresistor is similar to a pure resistor, and its volt-ampere characteristic is linear. Under a certain illumination, the larger the voltage, the larger the photocurrent, but the maximum dissipation of the photoresistor must be considered. Power, exceeding the rated voltage and maximum current can cause permanent damage to the photoresistor. The volt-ampere characteristics of the photodiode are similar to those of the phototransistor, but the photocurrent of the phototransistor is several tens of times larger than that of the photodiode of the same type. At zero bias, the photodiode has a photocurrent output, while the phototransistor has no photocurrent. Photocurrent output. The volt-ampere characteristics of silicon photocells are nonlinear under certain illumination.
2, lighting characteristics
The relationship between the spectral sensitivity of the photosensor and the incident light intensity is called the illumination characteristic. Sometimes the relationship between the output voltage or current of the photosensor and the incident light intensity is also called the illumination characteristic. It is also the parameter selected when designing the photosensor. One of the important bases. The illumination characteristics of a photoresistor, a silicon photo cell, a photodiode, and a phototransistor are shown in FIG. 5, FIG. 6, FIG. 7, and FIG.
Figure 5 Photometric characteristics of the photoresistor
Figure 6 Lighting characteristics of silicon photocells
Figure 7 Photometric characteristics of the photodiode
Figure 8 Light characteristic curve of phototransistor
It can be seen from the illumination characteristics of the above four kinds of photosensitive devices that the illumination characteristics of the photoresistor and the phototransistor are nonlinear, and generally it is not suitable for linear detection components. The open circuit voltage of the silicon photo cell is also nonlinear and saturated, but the short circuit of the silicon photo cell The current is in good linearity. Therefore, when a silicon photocell is used as a measuring component, a good linear relationship between short-circuit current and illuminance should be utilized. The short-circuit current refers to the current when the external load resistance is much smaller than the internal resistance of the silicon photocell. When the load is below 20Ω, the short-circuit current and the illuminance are linear, and the smaller the load, the better the linear relationship and the wider the linear range. The light-emitting characteristics of the photodiode are also linear, and the phototransistor is saturated at a large current. Therefore, when a linear detecting element is used, a photodiode can be selected instead of a phototransistor.
Third, the experimental instrument
GT-CGOP photosensitive sensor experiment instrument consists of photoresistor, photodiode, phototransistor, silicon photocell four kinds of photosensors and DC constant voltage source GT-VC3, LED, Ф2.2 fiber, fiber optic seat, black box (nine-hole plate experiment box) ), digital voltmeter, resistance box (self-prepared), low-frequency signal generator (self-prepared), oscilloscope (self-prepared), short-circuit bridge and wire, etc., as shown in Figure 9 main experimental instruments and components.
Figure 9-1 GT-VC3 DC constant voltage source panel
Figure 9-2 Light bulb box
Figure 9-3 Launch tube
Figure 9-4 Receiver tube
Figure 9-5 Receiver tube
Figure 9-6 Photosensitive resistor
Figure 9-7 Silicon Photo Battery
Figure 9-8 Photodiode
Figure 9-9 Phototransistor
Figure 9-10 Resistance box 1kΩ
Figure 9-11 Resistance box 1kΩ
Figure 9-12 Resistance box 470Ω
Figure 9-13 Resistance box 10Ω
Figure 9-14 Resistance Box 4.7KΩ
Figure 9-15 Resistance box 47Ω
Figure 9-16 Capacitor box 1uF
Figure 9-17 Speaker box
Figure 9-18 NPN triode box
Figure 9-19 Shorting bridge
Figure 9-20 9-hole experimental motherboard (inside the box)
During the experiment, the experimental components are placed in the nine-hole plug-in board in the dark box. The connection between the components in the box and the external power supply and the measuring instrument is realized through the connecting hole on the left side of the black box; the light intensity can be changed by changing the power supply of the light source (light bulb component box). The voltage or the distance from the source to the sensor is adjusted (changing the position of the component in the nine-well plate). The experiment can be performed under both natural light conditions and in dark light. The experimental method is simple and operability. It can comprehensively study the characteristics of various photoelectric sensors and expand other experiments to improve students' practical ability and provide a good platform for the school to carry out open physical design experiments. Figure 10 below shows the distance relationship between two adjacent nine holes in a nine-hole plate.
Figure 10 Distance between the nine-hole plate jacks
Fourth, the experimental content
The corresponding illumination intensity in the experiment is relative light intensity, and the relative light intensity can be adjusted by changing the point source voltage or changing the distance between the point source and each photoelectric sensor. The adjustment range of the light source voltage is 0 to 12V, and the distance between the light source and the sensor can be adjusted from 5 to 230 mm.
1, the characteristics of the photoresistor experiment
1.1. Photovoltaic voltammetric characteristics experiment
Figure 11 Photoresistor characteristic test circuit
(1) Connect the experimental circuit according to the schematic diagram 11, and place the tungsten filament light box for the light source, the photosensitive resistor box for the detection, and the resistance box in the black box nine-hole plug-in board.
The source is provided by GT-VC3 DC constant voltage source, and the light source voltage is 0~12V (adjustable).
(2) By changing the light source voltage or adjusting the distance between the light source and the photoresistor to provide a certain intensity, each time under certain lighting conditions, the measured plus
5 photocurrent data when the voltage U is +2V, +4V, +6V, +8V, +10V on the photoresistor, ie
And calculate the light at the same time
Resistance of the resistance
. In the future, the above experiment is repeated by gradually increasing the relative light intensity, and 5 to 6 times different light intensity experimental data are measured.
(3) A set of volt-ampere characteristic curves of the photoresistor are drawn based on the experimental data.
1.2. Photometric characteristics of photoresistor
(1) Connect the experimental circuit according to the schematic diagram 11. The tungsten light box for the light source, the photosensitive resistor box for the detection, and the resistance box are placed in the black box nine-hole plug-in board, and the power supply is provided by the GT-VC3 DC constant voltage source.
(2) From U=0 to U=12V, each time a certain applied voltage is measured, the photo-resistance is measured from the “weak light†to the gradually enhanced photoelectricity.
Stream data, ie:
At the same time, calculate the resistance of the photoresistor at this time, namely:
.
(3) Draw a set of illumination characteristics of the photoresistor based on the experimental data.
2. Characteristics experiment of silicon photocell
2.1. Voltammetric characteristics of silicon photocells
(1) The tungsten light box for the light source, the silicon photocell box for detection, and the resistance box are placed in the black box nine-hole plug-in board, the power supply is provided by the GT-VC3 DC constant voltage source, and the RX is connected to the jack of the dark box. So that it can be connected to an external resistor box. Connect the experimental circuit according to Figure 12. When the switch K points to "1", the voltmeter measures the open circuit voltage Uoc. When the switch points to "2", the RX is short-circuited, and the voltmeter measures the R voltage UR. The light source is made of tungsten wire lamp, the light source voltage is 0~12V (adjustable), and the resistance box is connected in series (0~10000Ω adjustable).
(2) First adjust the adjustable light source to the relative light intensity to the "weak light" position, and measure the photocurrent Iph and photovoltage USC of the silicon photocell every time under a certain illumination.
Relationship (0 ~ 10000 Ω) data under different load conditions, where
. (10.00 is the sampling resistance R), gradually increase later
The above experiment was repeated for relative light intensity (5-6 times).
(3) Draw a set of volt-ampere characteristics of the silicon photo cell based on the experimental data.
2.2. Photometric characteristics of silicon photocells
(1) The experimental circuit is shown in Figure 12, and the resistance box is adjusted to 0 Ω.
(2) First adjust the adjustable light source to the relative light intensity to the "weak light" position, and measure the silicon each time under a certain illumination.
Figure 12 Silicon Photovoltaic Characteristic Test Circuit
The open circuit voltage Uoc of the photovoltaic cell and the short circuit current IS, wherein the short circuit current is
(sampling
The resistance R is 10.00 Ω), and the relative light intensity (5 to 6 times) is gradually increased gradually, and the above experiment is repeated.
(3) Draw the light characteristic curve of the silicon photo cell based on the experimental data.
3, the characteristics of the photodiode experiment
3.1. Photodiode voltammetric characteristics experiment
(1) Connect the experimental circuit according to the schematic diagram 13, and place the tungsten light box for the light source, the photodiode box for detection, and the resistance box in the black box nine-hole plug-in board, and the power supply is provided by the GT-VC3 DC constant voltage source. The light source voltage is 0~12V (adjustable).
(2) First adjust the adjustable light source to the relative light intensity to the "weak light" position, and measure the relationship between the reverse bias voltage applied to the photodiode and the generated photocurrent each time under a certain illumination. Current:
Figure 13 Photodiode characteristic test circuit
(l.00KΩ is the sampling resistance R), and then gradually increase the relative light intensity (5-6 times), repeat the above experiment.
(3) Draw a set of volt-ampere characteristics of the photodiode based on the experimental data.
3.2, photodiode luminosity characteristics experiment
(1) Connect the experimental circuit according to the schematic diagram 13.
(2) The reverse bias voltage starts from U=0 to U=+l2V. Each time the photodiode is measured at a certain reverse bias voltage, the relative illuminance is “weak light†to gradually increase.
Photocurrent data, in which photocurrent
(l.00KΩ is the sampling resistor R).
(3) Draw a set of illumination characteristics of the photodiode based on the experimental data.
4, phototransistor characteristics experiment
4.1. Voltammetric characteristics of phototransistor
4.2. Photometric characteristics of phototransistor
5, the principle of fiber sensor and its application
5.1. Basic characteristics of fiber optic sensors
5.2, the basic principle of optical fiber communication
Temporary Hair Dye Use to enhance tones, refresh existing color, or play with fashion shades. Nourishing color is designed to fade out gradually over time. It works on Bleached hair directly. No need color developer.
Temporary hair color shampoo Flamingo Pink
SOLO GLOW HAIR COSMETICS , https://www.hairdyecolorfactory.com