CN112123978A - New electrostatic environment-friendly blackboard wiper - Google Patents

Abstract

The invention discloses a novel electrostatic environment-friendly blackboard erasing device, which comprises a blackboard connected with a pulse power supply and a capturing device, wherein a blackboard supporting part is made of a non-conductive insulator, black conductive paint is coated on the surface of the blackboard, parallel electrodes are connected to the left edge and the right edge of the blackboard, the two parallel electrodes are connected with the negative electrode of the pulse power supply, and the lower edge of the blackboard is connected with a grounding electrode; under the action of electrostatic repulsion, negatively charged chalk particles leave the board and are adsorbed by the capture device with positive charges on the opposite surface, so that the writing on the blackboard is erased. The invention designs a brand-new blackboard erasing device by utilizing the principle of electrostatic adsorption and repulsion, utilizes the repulsive force of the electrostatic to separate chalk particles from the blackboard, and utilizes the electrostatic adsorption to collect the chalk particles.

Description

New electrostatic environment-friendly blackboard wiper

technical field

The invention relates to the technical field of teaching utensils, in particular to a novel electrostatic environment-friendly blackboard-wiping device.

Background technique

In teaching activities, the blackboard and chalk are the most common tools. In the classroom, the teacher writes hard and uses the blackboard to show the important teaching content to the students. The main components of chalk that are widely used at present are limestone and gypsum, and blackboard erasers are generally made of felt. In some classes, the teacher has to write a lot of blackboard in one class, and it is necessary to erase the previously written content many times. Wiping the blackboard many times not only wastes time and energy, but also is not easy to clean. The large amount of dust generated when cleaning the blackboard also poses a potential threat to the health of teachers and students. Therefore, finding a quick, convenient and hygienic method for wiping the blackboard has important practicability.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the present invention provides a new type of electrostatic environment-friendly blackboard wiping device, which includes a blackboard connected to a pulsed power supply and a capture device. Connect parallel electrodes to the two edges, connect the two parallel electrodes to the negative pole of the pulse power supply, and connect a ground electrode to the lower edge of the blackboard; turn on the power switch, and connect the two parallel electrodes to the negative power pulse to make the blackboard surface Negatively charged, while the ground electrode is disconnected, the chalk writing on the blackboard surface is also negatively charged due to the contact with the board surface. Under the action of electrostatic repulsion, the chalk particles leave the board surface and are adsorbed by the positively charged capture device on the opposite side, thereby wiping Remove the writing on the blackboard.

Preferably, the capture device is a metal mesh arranged on the opposite side of the blackboard and parallel to the surface of the blackboard, the metal mesh is connected to the positive electrode of the pulse power supply, the bottom of the metal mesh is provided with a dust collection tank, and the metal mesh is connected to the metal mesh lift control device , the metal mesh can slide up and down under the motor drive to sweep the entire board surface.

Preferably, the distance between the metal mesh and the blackboard is 5-10 cm.

The invention uses the principle of electrostatic adsorption and repulsion to design a brand-new device for wiping the blackboard, uses the electrostatic repulsion to make the chalk particles separate from the blackboard, and uses the electrostatic adsorption to collect the chalk particles, the device is convenient, fast and can greatly reduce the chalk dust particles The generation of , not only solves the trouble of cleaning the blackboard, but also is beneficial to the improvement of the classroom environment.

Description of drawings

Figure 1 is a schematic diagram of wiping a blackboard using electrostatic repulsion.

Figure 2 is a side view of the electrostatic adsorption device.

Figure 3 is a schematic diagram of an electrostatic adsorption device.

Figure 4 is the work flow of the new electrostatic environmental protection blackboard wiper device.

Detailed ways

As we all know, charged objects can attract light and small objects. For example, a plastic ruler rubbed with fur can attract small paper scraps and dust. When polarization occurs, the surface generates polarization charges, and the polarization charges are attracted by the electric field, so that paper scraps, dust, etc. are adsorbed to the surface of the plastic ruler. If you continue to observe, you will find that after the light and small objects are attracted to the ruler, they will escape from the ruler in a short time. This is because part of the negative charge on the plastic ruler is transferred to the adsorbed light and small objects. The same charge Repel each other, so the confetti is repelled and detached from the plastic ruler. Based on this physical phenomenon, we proposed the idea of using electrostatic repulsion to wipe the blackboard and using electrostatic attraction to absorb and collect dust particles. The whole device mainly includes two parts:

1. Use electrostatic repulsion to wipe the blackboard: the support part of the blackboard is made of a non-conductive insulator, the surface is coated with black conductive paint, and parallel electrodes are connected to the left and right edges of the blackboard, and the two parallel electrodes are connected to the negative electrode of the pulse power supply. Connect a ground electrode to the lower edge of the blackboard, as shown in Figure 1. Turn on the power switch, connect the two parallel electrodes with a negative power pulse, so that the blackboard surface is negatively charged, while the ground electrode is disconnected, the chalk writing on the blackboard surface is also negatively charged due to the contact with the board surface, under the action of electrostatic repulsion, The chalk particles leave the board and are adsorbed by the positively charged capture device on the opposite side, thereby erasing the writing on the blackboard. To achieve the desired effect, the electrostatic pulse can be cycled several times. After the cycle is completed, the power is automatically turned off, and the ground electrode is connected to ensure that the residual charge flows into the ground.

2. Use electrostatic attraction to collect dust: install a metal mesh parallel to the blackboard surface at a distance of about 5-10cm on the opposite side of the blackboard 1. The metal mesh is connected to the metal mesh lifting control device 2. This metal mesh can be driven by a motor. Swipe up and down to scan the entire board surface, and place it under the board surface when it is not powered on, as shown in Figure 2. When in use, connect the metal mesh to the positive pole of the pulse power supply to attract negatively charged chalk ash particles. After the chalk ash particles contact the metal mesh, discharge occurs, and then is collected by the collection device to avoid dust flying and causing environmental pollution, as shown in Figure 3.

The above two parts are the main parts of the non-polluting electrostatic blackboard wiping device. The whole working process of the device is shown in Figure 4. After 4-5 cycles, the system is automatically powered off and grounded.

At present, the most commonly used tools in classrooms at home and abroad are still blackboards and chalks. The most common method of erasing the blackboard is to erase it manually. Other methods of erasing the blackboard mentioned in the literature and patents include electric drive plate erasing, water washing and electrostatic adsorption. These methods have their advantages, but they also have some defects, such as electric-driven board wipers, which still use traditional felt to wipe the blackboard, but use electric drive instead of manpower, which cannot solve the problem of chalk dust pollution; washing with water The type of device is more complicated and needs to be equipped with a circulating water circuit, which is not suitable for most classroom environments; and the electrostatic adsorption type only solves the problem of absorbing chalk dust, and it still requires manpower to clean the blackboard. At present, these devices have not been widely promoted, and the main method of wiping the blackboard is manual wiping. Therefore, designing a convenient, quick and pollution-free blackboard wiping device has great practical value and application prospect.

The invention utilizes electrostatic repulsion to realize the removal of chalk writing on the blackboard. This design idea has not appeared in practice or online search, and is a brand-new idea to solve this problem; the use of electrostatic adsorption to collect dust can reduce the amount of dust to the greatest extent. Pollution is beneficial to the health of teachers and students; after the entire device is completed, the operation is very simple, just plug in the power switch to complete the task of cleaning the blackboard, and regularly empty the dust collection box, which is very practical.

Finally, it should be noted that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the The technical solutions described in the foregoing embodiments may be modified, or some technical features thereof may be equivalently replaced. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (3)

1. A novel electrostatic environment-friendly blackboard erasing device is characterized by comprising a blackboard connected with a pulse power supply and a capturing device, wherein a blackboard supporting part is made of a non-conductive insulator, black conductive paint is coated on the surface of the blackboard, parallel electrodes are connected to the left edge and the right edge of the blackboard, the two parallel electrodes are connected with the negative electrode of the pulse power supply, and the lower edge of the blackboard is connected with a grounding electrode; and when the power switch is turned on, the two parallel electrodes are connected with a negative power supply pulse to enable the blackboard surface to be charged negatively, meanwhile, the grounding electrode is in a disconnected state, the chalk writing on the blackboard surface is also charged negatively due to the fact that the chalk writing is in contact with the blackboard surface, and under the action of electrostatic repulsion, the chalk particles leave the blackboard surface and are adsorbed by the capture device with positive electricity on the opposite surface, so that the writing on the blackboard is erased.

2. The novel electrostatic environment-friendly blackboard erasing device according to claim 1, wherein the capturing device is a metal net which is arranged opposite to the blackboard and parallel to the blackboard surface, the metal net is connected with the positive pole of the pulse power supply, the bottom of the metal net is provided with a dust collecting groove, the metal net is connected with a metal net lifting control device, and the metal net can slide up and down under the driving of a motor to sweep the whole blackboard surface range.

3. The novel electrostatic environment-friendly blackboard erasing device according to claim 1, wherein the distance between the metal mesh and the blackboard is 5-10 cm.

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