CN208860970U - Gravitational acceleration measurement device based on array photoelectric sensor - Google Patents

Abstract

The utility model discloses a kind of acceleration of gravity measuring device based on array optical electric transducer, comprising: experiment tubing string, experiment tubing string are placed vertically, so that detectable substance from top to bottom makees the movement of falling object in experiment tubing string；It is set at the different height of experiment tubing string and is separated by the first array optical electric transducer and second array formula photoelectric sensor of pre-determined distance, wherein, each array optical electric transducer includes that multiple photoemission arranged along the vertical direction are received to pipe, and each photoemission reception generates detection signal to pipe when detectable substance is fallen at corresponding height；Processing circuit, processing circuit is connected with the first array optical electric transducer and second array formula photoelectric sensor respectively, and processing circuit receives the fall time of detection signal acquisition detectable substance that at least one photoemission reception in the detection signal and second array formula photoelectric sensor that generate to pipe generates pipe in pre-determined distance according at least one photoemission in the first array optical electric transducer.

Description

Gravitational acceleration measurement device based on array photoelectric sensor

technical field

The utility model relates to the technical field of experimental instruments, in particular to a gravitational acceleration measuring device based on an array photoelectric sensor.

Background technique

The experiment of measuring gravitational acceleration by free fall method is currently one of the basic experiments of undergraduate physics, and has become an indispensable part of current university physics experiments. It detects the magnitude of the free-falling gravity acceleration g by the free fall method of the object, and currently occupies an important position in the teaching and scientific research of university physics.

Since the calculation of the gravitational acceleration g needs to measure the vertical distance of the object falling at a distance of s and the time interval t of the object passing through this distance, the experimenter can obtain the magnitude of the gravitational acceleration g when the object falls by the difference-by-difference method. At present, the measurement of the interval length s is relatively accurate, while the measurement of the time interval t has a large deviation in the measurement results due to the limited measurement methods.

At present, the vast majority of free-fall gravity accelerometers on the market use a cylinder device and a photogate set on the cylinder. The photogate consists of a small spotlight bulb and a photosensitive tube. The infrared laser emitted by the bulb passes through a circular The center of the cylinder passes through the transparent cylinder and is received by the photosensitive tube, and the induction timing device counts the time. However, in the experiment, it is first necessary to spend a lot of time to adjust the position of the falling path of the steel ball, so that the falling point of the steel ball corresponds to the light path transmitted and received by the photoelectric gate, so that the falling point of the steel ball can pass through the light path of the photoelectric gate and reach the photoelectric gate. The triggering of the gate, and then the purpose of triggering the start and stop timing, respectively, requires a lot of experimental preparations. At the same time, during the falling process of the steel ball, the falling trajectory often deviates from the light path transmitted and received by the photoelectric gate, which leads to the failure of the steel ball to be detected during the falling process, resulting in the lack of experimental data at time t in the free fall experiment, which in turn leads to the failure of the experiment. Therefore, the current experimental device needs a lot of time to adjust the experiment before the experiment. During the experiment, the falling steel ball is often missed by the photoelectric gate, resulting in timing failure. The current experimental device has the problems of long experimental preparation time and low experimental success rate. shortcoming.

Utility model content

The present invention aims to solve one of the technical problems in the above technologies at least to a certain extent. Therefore, the purpose of the present invention is to propose a gravitational acceleration measurement device based on an array photoelectric sensor, which can improve the success rate of gravitational acceleration measurement experiments, save a lot of experimental preparation time, and make the experimental process more efficient.

In order to achieve the above purpose, the utility model proposes a gravitational acceleration measurement device based on an array type photoelectric sensor, including: an experimental pipe column, the experimental pipe column is placed vertically, so that the detection object can be passed through the experimental pipe column. The first array photoelectric sensor and the second array photoelectric sensor are arranged at different heights of the experimental column and are separated by a preset distance, wherein each array photoelectric sensor includes a plurality of photoelectric sensors. a pair of photo-transmitting-receiving tubes arranged along the vertical direction, each of the photo-transmitting-receiving pair tubes generates a detection signal when the detection object falls to a corresponding height; a processing circuit, the processing circuit is respectively connected with the An array photoelectric sensor is connected to the second array photoelectric sensor, and the processing circuit is based on a detection signal generated by at least one photoelectric transmitting-receiving pair tube in the first array photoelectric sensor and the second array photoelectric sensor The detection signal generated by at least one photoelectric transmitting and receiving pair tube acquires the falling time of the detected object within the preset distance, so as to calculate the gravitational acceleration according to the preset distance and the falling time.

According to the gravitational acceleration measuring device based on the array photoelectric sensor of the present invention, two array photoelectric sensors arranged at different heights of the experimental column and separated by a preset distance are used to determine that the detected object has fallen to the corresponding height respectively. Each array photoelectric sensor includes a plurality of photoelectric transmitting-receiving pairs arranged in the vertical direction, thereby effectively avoiding the possibility of the detection object being missed, improving the success rate of the gravitational acceleration measurement experiment, and before the measurement experiment There is no need to precisely adjust the falling path of the test object, and a lot of experimental preparation time is saved, making the experimental process more efficient.

In addition, the gravitational acceleration measurement device based on the array photoelectric sensor according to the present invention may also have the following additional technical features:

Each of the photo-transmitting-receiving pair tubes includes light-emitting diodes and photodiodes arranged at the same height.

The detection object is spherical, and the distance between adjacent photo-transmitting-receiving pairs of tubes in each array photoelectric sensor is less than or equal to the diameter of the detection object.

The processing circuit includes: a multi-channel photoelectric transmission and reception trigger control circuit set corresponding to each array photoelectric sensor, each channel of the photoelectric transmission and reception trigger control circuit is connected to the output end of a corresponding photoelectric transmission and reception pair tube, the The multi-channel photoelectric transmission and reception trigger control circuit generates a trigger signal according to the detection signal generated by the photoelectric transmission and reception pair tube in the corresponding array photoelectric sensor; the logic control circuit corresponding to each array photoelectric sensor, the logic control circuit and the The multi-channel photoelectric transmission and reception trigger control circuit is connected, and the logic control circuit generates a trigger timing signal according to the trigger signal; the single-chip microcomputer is connected with the logic control circuit, and the single-chip microcomputer is respectively based on the first array photoelectricity. The trigger timing signal corresponding to the sensor and the second array photoelectric sensor starts and stops timing to obtain the falling time of the detected object within the preset distance.

Each channel of the photoelectric transmitting and receiving trigger control circuit includes an operational amplifier, the positive input end of the operational amplifier is connected to the output end of the corresponding photoelectric transmitting and receiving pair tube, and the negative input end of the operational amplifier is connected to the reference voltage end, so the The output terminal of the operational amplifier is used as the output terminal of the photoelectric transmission and reception trigger control circuit to output the trigger signal, wherein the reference voltage provided by the reference voltage terminal is adjustable.

The logic control circuit includes a plurality of NOT gates and an OR gate, the input end of each NOT gate is connected to a corresponding output end of the photoelectric transmission and reception trigger control circuit, and the output end of each of the NOT gates It is connected with the input end of the OR gate, and the output end of the OR gate is connected with the single-chip microcomputer to output the trigger timing signal to the single-chip computer.

The top of the test column is provided with an adsorption piece for adsorbing and fixing the test object, and the bottom of the test column is provided with a mesh bag for receiving the test object that falls.

The gravitational acceleration measuring device based on the array photoelectric sensor further comprises an adsorption switch connected with the adsorption member.

The side wall of the experimental column is marked with a graduation line to facilitate setting the preset distance.

The gravitational acceleration measurement device based on the array photoelectric sensor further comprises a base for supporting the experimental pipe string, a screw arranged on the base and used for adjusting the height of the base, and a screw arranged on the base And a spirit level for calibrating the verticality of the experimental column.

Description of drawings

1 is a schematic structural diagram of a gravitational acceleration measuring device based on an array photoelectric sensor according to an embodiment of the present invention;

2 is a schematic structural diagram of an array photoelectric sensor according to an embodiment of the present invention;

3 is a schematic block diagram of a processing module according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a photoelectric transmitter and receiver trigger control circuit according to an embodiment of the present utility model;

5 is a schematic diagram of a logic control circuit according to an embodiment of the present utility model;

FIG. 6 is a schematic structural diagram of a gravitational acceleration measuring device based on an array photoelectric sensor according to an embodiment of the present invention.

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to be used to explain the present invention, but should not be construed as a limitation of the present invention.

As shown in FIG. 1 , the gravitational acceleration measurement device based on the array photoelectric sensor according to the embodiment of the present invention includes an experimental column 1 , and a first array photoelectric sensor arranged at different heights of the experimental column 1 and separated by a preset distance. The sensor 2 , the second array photoelectric sensor 3 , and the processing circuit 4 . Wherein, the test pipe string 1 is placed vertically, so that the test object 5 can freely fall in the test pipe string 1 from top to bottom. As shown in Fig. 2, each array photoelectric sensor includes a plurality of photo-transmitting-receiving pairs arranged in the vertical direction (6 in Fig. 2 as an example). A detection signal is generated when the corresponding height is reached. The processing circuit 4 is respectively connected with the first array photoelectric sensor 2 and the second array photoelectric sensor 3, and the processing circuit 4 can be based on the detection signal generated by at least one photoelectric transmitting and receiving pair tube in the first array photoelectric sensor 2 and the second array photoelectric sensor. The detection signal generated by at least one photoelectric transmitting and receiving pair tube in the type photoelectric sensor 3 obtains the falling time of the detection object 5 within the preset distance, so as to calculate the gravitational acceleration according to the preset distance and the falling time.

In an embodiment of the present invention, as shown in FIG. 2 , each photo-transmitting-receiving pair tube includes a light-emitting diode and a photodiode arranged at the same height. In an embodiment of the present invention, the detection object 5 is spherical, and the distance d between the adjacent photoelectric transmitting-receiving pair tubes in each array photoelectric sensor is less than or equal to the diameter R of the detection object 5 . Therefore, it can be ensured that when the detection object 5 falls, at least one photoelectric transmitting-receiving pair tube is blocked to generate a detection signal. The number of photo-emission-receiving pairs and the spacing between adjacent photo-emission-receiving pairs can be determined according to the size of the experimental column. Wherein, the distance between adjacent photo-emission-receiving pairs is much smaller than the above-mentioned preset distance, for example, the above-mentioned preset distance may be more than 10 cm, and the distance between adjacent photo-transmitting-receiving pairs may be in the order of millimeters. In this way, the distance between the pair of photo-transmitting-receiving tubes that generate detection signals in the first array-type photoelectric sensor 2 and the pairing photo-transmitting-receiving tubes that generate detection signals in the second array-type photoelectric sensor 3 can be prevented from being significantly different from those used to calculate the gravitational acceleration. The preset distance deviation is too large, so as to ensure the detection accuracy of gravitational acceleration.

In an embodiment of the present invention, as shown in FIG. 3 , the processing circuit 4 includes a multi-channel photoelectric transmit-receive trigger control circuit 41 corresponding to each array photoelectric sensor, and a logic control circuit 41 corresponding to each array photoelectric sensor. Circuit 42 and microcontroller 43. Among them, each photoelectric transmission and reception trigger control circuit 41 is connected to the output end of a corresponding photoelectric transmission and reception pair tube, and the multi-channel photoelectric transmission and reception trigger control circuit 41 can be generated according to the photoelectric transmission and reception pair tube in the corresponding array photoelectric sensor. The detection signal generates a trigger signal; the logic control circuit 42 is connected with the multi-channel photoelectric transmission and reception trigger control circuit 41, and the logic control circuit 42 can generate a trigger timing signal according to the trigger signal; The trigger timing signal corresponding to the array photoelectric sensor 2 and the second array photoelectric sensor 3 starts and stops the timing, so as to obtain the falling time of the detection object 5 within the preset distance.

In one embodiment of the present utility model, as shown in FIG. 4 , each photoelectric transmitting and receiving trigger control circuit 41 includes an operational amplifier, and the positive input end of the operational amplifier is connected to the output end of the corresponding photoelectric transmitting and receiving pair tube, and the operational amplifier The negative input terminal of 1 is connected to the reference voltage terminal, and the output terminal of the operational amplifier is used as the output terminal OUT of the photoelectric transmission and reception trigger control circuit 41 to output a trigger signal, wherein the reference voltage provided by the reference voltage terminal is adjustable. Further, as shown in Figure 4, the photo-transmitting-receiving pair tube includes a light-emitting diode DS1 and a photodiode D1, the anode of DS1 is connected to the +5V power supply through the resistor R1, the cathode is grounded, and the cathode of D1 is connected to the +5V power supply through the resistor R2, The anode is grounded through resistor R3. The operational amplifier model can be LM324AD, its positive input terminal is connected to the cathode of D1, the negative input terminal is connected to +5V power supply through resistor R19 and grounded through sliding rheostat R25. The reference voltage of the negative input terminal of the operational amplifier can be adjusted by adjusting the sliding rheostat R25.

In an embodiment of the present utility model, as shown in FIG. 5 , the logic control circuit 42 includes a plurality of NOT gates and one OR gate, and the input end of each NOT gate is connected to the output of a corresponding one-way photoelectric transmit-receive trigger control circuit The output terminal of each NOT gate is connected to the input terminal of the OR gate, and the output terminal Y of the OR gate is connected to the single-chip microcomputer 43 to output the trigger timing signal to the single-chip microcomputer 43.

Through the above-mentioned photoelectric transmission and reception trigger control circuit 41 and logic control circuit 42, when the light-emitting diode and the receiving diode are not blocked, the receiving diode is turned on, and the operational amplifier acts as a comparator, and its positive input terminal is high level. The voltage output is a high level, and the corresponding photoelectric transmission and reception trigger control circuit 41 outputs a high level when the optical paths of all the photoelectric transmission and reception pairs are not blocked. When the light-emitting diode and the receiving diode are blocked by the falling detection object 5, the receiving diode cannot receive the light signal and shuts down, causing the voltage of the positive input terminal of the operational amplifier to drop to 0. Through comparison, the output voltage of the operational amplifier is low level , the falling edge of the high level conversion to the low level is the trigger signal generated when the detection object 5 falls to the array photoelectric sensor. Each trigger signal first goes through the NOT gate to invert, and then passes through the OR gate to combine in the form of multi-channel AND. When any trigger signal is a falling edge signal, the trigger timing signal output by the OR gate changes to a high level from a rising edge. . The trigger timing signals generated by the photoelectric transmitter and receiver in the first array photoelectric sensor 2 and the second array photoelectric sensor 3 corresponding to the preset distances respectively trigger the single chip timing to achieve the purpose of timing.

In addition, the periphery of the single-chip microcomputer 43 can also be configured with a keyboard, a display and a voice announcer. The keyboard can be used to set the experiment, and the display and the voice announcer can be used to display and announce the experiment results respectively.

Further, as shown in FIG. 6 , the top of the experimental column 1 is provided with an adsorption member 6 for adsorbing and fixing the detection object 5 , and the bottom of the experimental column 1 is provided with a mesh bag 7 for receiving the falling detection object 5 . It can be used to buffer the falling detection object 5 to avoid damage to other devices at the bottom due to the large impact force when the detection object 5 falls.

Further, as shown in FIG. 6 , the gravitational acceleration measurement device based on the array photoelectric sensor according to the embodiment of the present invention may further include an adsorption switch 8 connected to the adsorption member 6 . The adsorption member 6 adsorbs the detection substance 5 and releases the detection substance 5 .

Further, as shown in FIG. 6 , a scale line 9 is marked on the side wall of the experimental column 1 to facilitate setting the above-mentioned preset distance. In a specific embodiment of the present invention, the minimum division value of the scale line 9 is 0.01mm.

Further, as shown in FIG. 6 , the gravitational acceleration measurement device based on the array photoelectric sensor according to the embodiment of the present invention may further include a base 10 for supporting the experimental column 1 , a base 10 arranged on the base 10 and used for adjusting the base 10 . The height of the screw 11 and the level 12 provided on the base 10 and used to calibrate the verticality of the experimental string 1 .

Further, as shown in FIG. 6 , the gravitational acceleration measurement device based on the array photoelectric sensor according to the embodiment of the present invention may further include a vacuum pump 13 for evacuating the experimental column 1 , so as to create a vacuum pump 13 for the entire free fall experiment. vacuum environment.

Further, as shown in FIG. 6 , the gravitational acceleration measurement device based on the array photoelectric sensor according to the embodiment of the present invention may further include a power supply 14 , and the power supply 14 can supply power to the electrical appliances in the entire device.

In a specific embodiment of the present invention, the experimental column 1 is a glass tube, the detection object 5 is a steel ball, the adsorption member 6 is an electromagnetic adsorption member, the adsorption switch 8 is an electromagnetic adsorption switch, and the single-chip microcomputer 43 can use a C8051F300 chip.

To sum up, according to the gravitational acceleration measuring device based on the array photoelectric sensor according to the embodiment of the present invention, two array photoelectric sensors arranged at different heights of the experimental column and separated by a preset distance are used to determine the detection objects respectively. Falling to the corresponding height, each array photoelectric sensor includes a plurality of photoelectric transmitting-receiving pairs arranged in the vertical direction, thereby effectively avoiding the possibility of the detection object being missed, and improving the success of the gravitational acceleration measurement experiment It also saves a lot of experimental preparation time and makes the experimental process more efficient.

In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limitations of the present invention, and those of ordinary skill in the art are within the scope of the present invention Variations, modifications, substitutions and variations can be made to the above-described embodiments.

Claims (10)

1. a kind of acceleration of gravity measuring device based on array optical electric transducer characterized by comprising

Tubing string is tested, the experiment tubing string is placed vertically, so that detectable substance is from top to bottom made freely to fall in the experiment tubing string Body movement；

It is set at the different height of the experiment tubing string and is separated by the first array optical electric transducer and second of pre-determined distance Array optical electric transducer, wherein each array optical electric transducer includes multiple photoemission arranged along the vertical direction It receives to pipe, each photoemission reception generates detection signal to pipe when the detectable substance is fallen at corresponding height；

Processing circuit, the processing circuit respectively with the first array optical electric transducer and the second array formula photoelectric transfer Sensor is connected, and the processing circuit is received according at least one photoemission in the first array optical electric transducer to Guan Sheng At detection signal and the second array formula photoelectric sensor at least one photoemission receive the detection letter generated to pipe Number the fall time of the detectable substance in the pre-determined distance is obtained, so as to according to the pre-determined distance and the fall time Calculate acceleration of gravity.

2. the acceleration of gravity measuring device according to claim 1 based on array optical electric transducer, which is characterized in that Each photoemission reception includes the light emitting diode and photodiode being set at sustained height to pipe.

3. the acceleration of gravity measuring device according to claim 1 based on array optical electric transducer, which is characterized in that The detectable substance is spherical, and adjacent photoemission is received to the spacing of pipe less than or equal to institute in each array optical electric transducer State the diameter of detectable substance.

4. the acceleration of gravity measuring device according to claim 1 based on array optical electric transducer, which is characterized in that The processing circuit includes:

The multichannel photoemission of corresponding each array optical electric transducer setting receives trigger control circuit, per the photoelectricity described all the way Transmitting, which receives trigger control circuit and receives with a corresponding photoemission, is connected to the output end of pipe, the multichannel photoemission It receives trigger control circuit and receives the detection signal life generated to pipe according to photoemission in corresponding array optical electric transducer At trigger signal；

The logic control circuit of corresponding each array optical electric transducer setting, the logic control circuit and the multichannel photoelectricity Transmitting receives trigger control circuit and is connected, and the logic control circuit generates triggering timing signal according to the trigger signal；

Single-chip microcontroller, the single-chip microcontroller are connected with the logic control circuit, and the single-chip microcontroller is respectively according to first array Photoelectric sensor and the corresponding triggering timing signal enabling timing of the second array formula photoelectric sensor and stopping timing, to obtain Take fall time of the detectable substance in the pre-determined distance.

5. the acceleration of gravity measuring device according to claim 4 based on array optical electric transducer, which is characterized in that Receiving trigger control circuit per the photoemission all the way includes operational amplifier, the positive input terminal connection of the operational amplifier The output end to pipe is received to corresponding photoemission, the negative input end of the operational amplifier is connected to reference voltage end, institute The output end that the output end for stating operational amplifier receives trigger control circuit as the road photoemission exports the trigger signal, Wherein, the reference voltage that the reference voltage end provides is adjustable.

6. the acceleration of gravity measuring device according to claim 5 based on array optical electric transducer, which is characterized in that The logic control circuit include multiple NOT gates and one or, the input terminal of each NOT gate is connected to corresponding institute all the way State the output end that photoemission receives trigger control circuit, the output end of each NOT gate and described or door input terminal phase Even, described or door output end is connected to export the triggering timing signal to the single-chip microcontroller with the single-chip microcontroller.

7. the acceleration of gravity measuring device according to claim 1 based on array optical electric transducer, which is characterized in that The adsorption piece for adsorbing the fixed detectable substance, the bottom setting of the experiment tubing string are provided at the top of the experiment tubing string Have for accepting the detectable substance mesh bag to fall.

8. the acceleration of gravity measuring device according to claim 7 based on array optical electric transducer, which is characterized in that It further include the absorption switch being connected with the adsorption piece.

9. the acceleration of gravity measuring device according to claim 1 based on array optical electric transducer, which is characterized in that The side wall of the experiment tubing string indicates graduation mark, in order to which the pre-determined distance is arranged.

10. the acceleration of gravity measuring device according to claim 1 based on array optical electric transducer, feature exist In further including the pedestal for being used to support the experiment tubing string, setting on the base and for adjusting the height of the pedestal Screw and setting on the base and for demarcate it is described experiment tubing string verticality level meter.