Photoelectric effect exploration instrument

Abstract

The utility model discloses a photoelectric effect exploration instrument which comprises a circuit board and a light source, and one side of the circuit board is provided with a physical diagram formed by sequentially connecting a control switch, a potentiometer, a voltage sensor, a micro-current sensor and a photoelectric tube through wires; the other side of the circuit board is provided with a circuit which corresponds to the position of the physical diagram and is connected with the physical diagram in the same way; the control switch and one end of the photoelectric tube are exposed on the circuit; the light source is mounted on the circuit board close to the photoelectric tube and exposed on one side of the circuit; wherein the light beam emitted by the light source can irradiate on the cathode plate of the phototube frontally, the demonstration instrument effectively combines the modern technology and the physical experiment by utilizing a Lanwei digital instrument, not only is the measurement accurate, but also the current and voltage images can be directly presented on computer software, so that students can understand the concept of saturated photocurrent; the problem that a pointer type electric meter cannot demonstrate the instantaneity of the photoelectric effect is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of teaching aids, in particular to a photoelectric effect exploration instrument. Background Art

[0002] In high school physics textbooks, "photoelectric effect" is an important teaching content. Students can conduct experiments based on the content in the textbooks to understand the photoelectric effect phenomenon.

[0003] In actual teaching, the current textbooks only provide experimental circuit diagrams, and teaching has long remained at the level of preaching. Students do not have the opportunity to see the intuitive phenomenon of the photoelectric effect with their own eyes, and there are no specific experimental exploration links. Moreover, the photoelectric effect experiment instrument in the laboratory has a closed structure and is expensive, which is not conducive to students' understanding of its internal working principles and is difficult to use widely. Utility Model Content

[0004] The purpose of the utility model is to provide a photoelectric effect exploration instrument to solve the technical problems in the existing devices.

[0005] In order to solve the above technical problems, the utility model specifically provides the following technical solutions: a photoelectric effect exploration instrument, comprising a circuit board and a light source, one side of the circuit board is provided with a physical diagram formed by a control switch, a potentiometer, a voltage sensor, a micro-current sensor and a photoelectric tube connected in sequence through wires;

[0006] A circuit corresponding to the position of the physical diagram and having the same connection method is arranged on the other side of the circuit board, and one end of the control switch and the photoelectric tube are both exposed on the circuit;

[0007] The light source is mounted on a circuit board near the photoelectric tube and exposed on one side of the circuit;

[0008] The light beam emitted by the light source can be irradiated positively onto the cathode plate of the photoelectric tube.

[0009] As a preferred solution of the utility model, the light source is an LED color bulb, the light source is connected to an external power source via a wiring plug, and a through hole for the wiring plug to pass through is provided on a side of the circuit board close to the light source.

[0010] As a preferred solution of the utility model, a box body is arranged on the circuit board at one side of the photoelectric tube, and the box body can cover the photoelectric tube;

[0011] A hole having a size similar to that of the cathode plate of the photoelectric tube is formed on one side of the box body close to the light source.

[0012] As a preferred solution of the utility model, a data collector is also provided on the back of the circuit board, and the signal access end of the data collector is connected to the voltage sensor and the microcurrent sensor through wires, and the signal output end of the data collector is connected to an external control system.

[0013] As a preferred solution of the utility model, a variable resistance box is arranged on the back of the circuit board, and the variable resistance box and the micro-current sensor are connected in parallel through a wire.

[0014] As a preferred solution of the utility model, a bracket is provided on one side of the circuit board as shown in the physical diagram.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] The demonstrator uses Longway digital instruments to effectively combine modern technology with physical experiments. It not only measures accurately, but also can directly present images of current and voltage on computer software, which helps students understand the concept of saturated photocurrent. It also solves the problem that pointer-type meters cannot demonstrate the instantaneous nature of the photoelectric effect.

[0017] At the same time, white acrylic board and solid wood are used as the main board materials, which are simple, beautiful, strong and durable; switching power supply, potentiometer, boat switch and other circuit components are used, which are easy to operate, economical and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the implementation of the utility model or the technical solution in the prior art, the following is a brief introduction to the drawings required for the implementation or the prior art description. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0019] Figure 1 It is a front view schematic diagram of the overall structure of the utility model;

[0020] Figure 2 It is a schematic diagram of the back side of the overall structure of the utility model;

[0021] Figure 3 For the utility model Figure 1 The front view of the overall structure after removing the box body;

[0022] Figure 4 This is a schematic diagram of the circuit structure connection of the utility model;

[0023] The numbers in the figure represent the following:

[0024] 1. Circuit board; 2. Light source; 3. Control switch; 4. Potentiometer; 5. Voltage sensor; 6. Microcurrent sensor; 7. Phototube; 8. Circuit; 9. Through hole; 10. Box body; 11. Hole; 12. Data collector; 13. Variable resistance box; 14. Bracket; 15. Power supply; 16. Small hole. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] like Figure 1-3 As shown, a photoelectric effect exploration instrument includes a circuit board 1 and a light source 2. A control switch 3, a potentiometer 4, a voltage sensor 5, a microcurrent sensor 6 and a photoelectric tube 7 are connected in sequence through wires on one side of the circuit board 1;

[0027] On the other side of the circuit board 1, a circuit 8 is provided, which has the same connection method as the physical figure and corresponds to the position of the physical figure. One end of the control switch 3 and the photoelectric tube 7 are exposed on the circuit 8.

[0028] The light source 2 is mounted on a circuit board near the photoelectric tube 7 and exposed on the side of the circuit 8;

[0029] The light beam emitted by the light source 2 can be irradiated on the cathode plate of the photoelectric tube 7 in the front direction.

[0030] The demonstrator uses Longway digital instruments to effectively combine modern technology with physical experiments. It not only measures accurately, but also can directly present images of current and voltage on computer software, which helps students understand the concept of saturated photocurrent. It also solves the problem that pointer-type meters cannot demonstrate the instantaneous nature of the photoelectric effect.

[0031] At the same time, white acrylic board and solid wood are used as the main board materials, which are simple, beautiful, strong and durable; switching power supply, potentiometer, boat switch and other circuit components are used, which are easy to operate, economical and practical.

[0032] Specifically, Figure 1-3 As shown, the light source 2 is an LED color bulb, which is connected to an external power source via a wiring plug, and a through hole 9 for the wiring plug to pass through is provided on one side of the circuit board 1 close to the LED color bulb.

[0033] Led color bulbs can change the frequency and intensity of light through the remote control, which is convenient and quick to operate.

[0034] Furthermore, a box body 10 is provided on the circuit board 1 located on one side of the photoelectric tube 7, and the box body 10 can cover the photoelectric tube 7;

[0035] A hole 11 having a size similar to that of the cathode plate of the photoelectric tube 7 is provided on one side of the box body 10 close to the light source 2. This can reduce the interference of stray light and make the experiment more accurate.

[0036] Preferably, the box body 10 may be black.

[0037] Since the photoelectric tube 7 generally has two structures similar to pins, this structure is mainly used for connecting the wires in the physical diagram located on the other side of the circuit board 1.

[0038] Therefore, the surface of the circuit board 1 that contacts the photoelectric tube 7 is provided with holes 16 of two sizes, and the two holes 16 can be used for the photoelectric tube 7 to be inserted.

[0039] The model of the phototube 7 may be a GD-2A phototube. Compared with other phototubes, the GD-2A phototube is less affected by white light and is cheaper.

[0040] Specifically, Figure 1-3 As shown, a data collector 12 is also provided on the back of the circuit board 1. The signal access end of the data collector 12 is connected to the voltage sensor 5 and the microcurrent sensor 6 through wires, and the signal output end of the data collector 12 is connected to the external control system.

[0041] The external control system can be a computer. Download the Longway DIS8.0 software, open the software to collect data, and directly present the images of current and voltage on the computer software, which is helpful for students to understand the concept of saturated photocurrent.

[0042] Further, such as Figure 1-3 As shown, a variable resistance box 13 is provided on the back of the circuit board 1, and the variable resistance box 13 and the micro-current sensor 6 are connected in parallel through a wire. The parallel connection between the resistance box and the micro-current sensor 6 can expand the measurement range, thereby achieving the purpose of protecting the micro-current sensor 6.

[0043] Since the circuit board 1 generally needs to be stood up for students to visit, the circuit board needs to be provided with a supporting structure.

[0044] Specifically, Figure 1-3 As shown, the circuit board 1 is provided with a bracket 14 on one side of the actual picture, and the entire circuit board 1 is erected by the support of the bracket 14.

[0045] like Figure 1-4 As shown, the method of using the demonstrator is as follows: prepare the required circuit components as above;

[0046] Each circuit component is placed on the back of the circuit board 1 and connected with wires according to the design principle diagram. The photoelectric tube 7 is placed on the front cathode plate of the circuit board 1, facing the light source, and the two poles are wound with fine copper wire, passing through the hole 16 and connected in series with the current sensor 5; the knob of the potentiometer 4 passes through the small hole and is locked with a nut; the button of the boat switch is placed in front of the circuit board; the Langwei sensor and data acquisition device and other components are fixed to the back of the circuit board 1 with a snap fastener and a strong sticker;

[0047] The photoelectric tube 7 is covered with a box body 10, a rectangular hole 11 of a similar size to the cathode plate is cut on the side close to the light source, and is adhered to the circuit board 1 with a transparent wide tape; the resistance box 13 can be connected in parallel with the micro-current sensor 6 to expand the range and protect the micro-current sensor 5;

[0048] Use a data cable to connect the microcurrent sensor 5, the voltage sensor 6 and the data acquisition device, and then connect them to the computer, download the Langwei DIS8.0 software, and open the software to collect data.

[0049] The four main laws of the photoelectric effect can be explored through this demonstrator, as follows:

[0050] 1. Verification of the law of photoelectric effect 1: There is a cut-off frequency

[0051] First, open the DIS measurement software, adjust the microcurrent sensor 6 to zero, turn on the power supply 15, select red weak light, record the current reading as 0, then increase the light intensity, the current reading is still 0; then select blue strong light, the current reading is not 0, then reduce the light intensity, the current reading is still not 0; multiple experiments can verify whether the photoelectric effect occurs and is related to the light intensity but not the light frequency.

[0052] 2. Verify the law of photoelectric effect 2 - the photoelectric effect is instantaneous

[0053] First, select blue weak light, turn off the light, then open the DIS measurement software, adjust the microcurrent sensor to zero, turn on the light, and find that current is generated immediately;

[0054] Many experiments have verified that when the frequency exceeds the cutoff frequency, no matter how weak the incident light is, a photocurrent will be immediately generated when it hits the metal.

[0055] 3. Verify the law of photoelectric effect 3 - there is a cut-off voltage

[0056] Open the DIS measurement software, adjust the microcurrent sensor and voltage sensor to zero, select strong green light, apply reverse voltage, adjust the potentiometer so that the voltage across the phototube is 0, then turn the potentiometer clockwise to gradually increase the reverse voltage until the photocurrent is 0, and record the voltage reading at this time; then select weak green light, repeat the operation just now, and record the voltage reading at this time;

[0057] Through multiple experiments, within the allowable error range, it can be verified that for the same metal, the cutoff voltage is the same for light of a certain frequency, regardless of the intensity of the light.

[0058] 4. Verification of the Photoelectric Effect Law 4 - Existence of Saturation Current

[0059] Open the DIS measurement software, establish a coordinate system with voltage as the horizontal axis and current as the vertical axis, then apply a forward voltage across the phototube, select strong yellow light, and adjust potentiometer 4 to gradually increase the voltage across the phototube 7 from zero. At this time, the current first gradually increases and then tends to the saturation value. Select weak yellow light and repeat the experimental operation. At this time, the current saturation value is smaller than that of strong yellow light.

[0060] After many experiments, within the allowable error range, it can be finally verified that when the lighting conditions remain unchanged, as the applied voltage increases, the photocurrent tends to a saturation value; when the frequency of light remains unchanged, the stronger the incident light, the greater the saturation current.

[0061] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A photoelectric effect exploration instrument, characterized in that: The invention comprises a circuit board (1) and a light source (2), wherein one side of the circuit board (1) is provided with a physical diagram in which a control switch (3), a potentiometer (4), a voltage sensor (5), a microcurrent sensor (6) and a photoelectric tube (7) are connected in sequence through wires; A circuit (8) having a position corresponding to that in the physical diagram and having the same connection method is provided on the other side of the circuit board (1); one end of the control switch (3) and the photoelectric tube (7) are both exposed on the circuit (8); The light source (2) is mounted on a circuit board near the photoelectric tube (7) and exposed on a side of the circuit (8); The light beam emitted by the light source (2) can be irradiated positively onto the cathode plate of the photoelectric tube (7).

2. A photoelectric effect exploration instrument according to claim 1, characterized in that: The light source (2) is an LED color bulb, the light source (2) is connected to an external power source via a wiring plug, and a through hole (9) for the wiring plug to pass through is provided on a side of the circuit board (1) close to the light source (2).

3. A photoelectric effect exploration instrument according to claim 1, characterized in that: A box body (10) is arranged on the circuit board (1) at one side of the photoelectric tube (7), and the box body (10) can cover the photoelectric tube (7); A hole (11) having a size approximately equal to that of the cathode plate of the photoelectric tube (7) is provided on a side of the box body (10) close to the light source (2).

4. A photoelectric effect exploration instrument according to claim 1, characterized in that: A data collector (12) is also provided on the back of the circuit board (1); a signal input end of the data collector (12) is connected to the voltage sensor (5) and the microcurrent sensor (6) via wires, respectively; and a signal output end of the data collector (12) is connected to an external control system.

5. A photoelectric effect exploration instrument according to claim 1, characterized in that: A variable resistance box (13) is provided on the back of the circuit board (1), and the variable resistance box (13) and the micro-current sensor (6) are connected in parallel via a wire.

6. A photoelectric effect exploration instrument according to claim 1, characterized in that: The circuit board (1) is provided with a bracket (14) on one side thereof provided with the physical image.

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