Electrostatic protection of electronic classroom
A small amount of static electricity can cause harm to computers and other equipment in electronic classrooms. The presence of static electricity will lightly cause instantaneous changes in the potential of precision components in computers and other equipment, resulting in the loss or change of information in the memory. It can lead to failure or complete damage of individual components or even the entire equipment. Static electricity can also cause psychological irritability to teachers and students, affect the physical and mental health of operators, and reduce learning efficiency.
Although computers, peripherals, and network equipment themselves all carry out anti-static design on components and circuits, it is not enough to rely on these measures alone. When building electronic classrooms, measures must be taken to reduce the source of static electricity in accordance with relevant standards and minimize the possible impact of static electricity on electronic classrooms. These measures mainly include electrostatic grounding, electrostatic shielding, and installation of anti-static flooring.
1. Grounding and shielding
Grounding and shielding are the *basic anti-static measures.
Grounding can lead the accumulated static electricity to the earth in time. There will inevitably be some conductors in the electronic classroom, such as a computer case. These conductors must be reliably connected to the ground, and there must be no isolated conductors insulated to the ground. The electrostatic grounding must be connected to the grounding device via a current-limiting resistor. The resistance of the current-limiting resistor should be 1MΩ, and the connecting wire should have sufficient mechanical strength and chemical stability.
Static electricity and electromagnetic induction easily cause information disorder in magnetic storage media. The shielding can prevent static electricity from intruding into the interior of related equipment, and at the same time can prevent electromagnetic induction from affecting magnetic storage media such as tapes and disks. For example, the use of iron disk cabinets is a simple and easy way to prevent static electricity and electromagnetic induction.
2. Install anti-static floor
If the electronic classroom is not equipped with a raised floor, it must be laid on a static conductive floor. The static conductive floor should be glued to the building ground with conductive glue.
However, for the convenience of wiring, electronic classrooms now generally have floors. The floor is precisely the main source of static electricity, so various types of anti-static floors have emerged and are widely used in many occasions, including electronic classrooms.
The anti-static floor can be made of steel, aluminum or other flame-retardant materials, but there must be no exposed metal parts on the surface. The surface of the anti-static floor is electrostatically conductive, and one of its important performance indicators is the system resistance. According to the "Technical Requirements for Raised Floors for Computer Room" formulated by our country, the system resistance of the unit floor should meet the current national standards. The resistance from the floor surface to the grounding system is between 105 and 108 Ω. The lower limit is to ensure personal protection. The upper limit of the safe resistance value for electric shock is to prevent the generation of static electricity due to the excessive resistance value.
In addition, the work surface and seat cushion cover material in the electronic classroom should be electrostatically conductive. Electrostatic ground, anti-static floor, work surface, and seat cushion cover must be grounded statically.