Electrostatic protection in electronic classrooms
"In case, just in case" talk about static protection in electronic classrooms
Small static electricity, the harm to the computer and other equipment in the electronic classroom can not be underestimated. The presence of static electricity can cause instantaneous changes in the potential of precision components in devices such as computers, resulting in loss or change of information in the memory. This can lead to malfunction or complete damage to individual components or even the entire device. Static electricity will also bring psychological irritability to teachers and students, affecting the physical and mental health of operators and reducing learning efficiency.
Although computers, peripherals, and network devices now have antistatic designs on components and circuits, relying on these measures alone is not enough. When building an electronic classroom, measures must be taken to reduce the source of static electricity in accordance with relevant standards, and to minimize the possible impact of static electricity on the electronic classroom. These measures mainly include electrostatic grounding, electrostatic shielding, and installation of anti-static floors.
1, grounding and shielding
Grounding and shielding are the most basic anti-static measures.
Grounding can introduce accumulated static electricity into the earth in time. There are inevitably some conductors in the electronic classroom, typically computer cabinets. These conductors must be reliably connected to the earth, and there must be no isolated conductors insulated from the ground. The electrostatic grounding must be connected to the grounding device via a current limiting resistor. The current limiting resistor should have a resistance of 1 MΩ. The connecting wire should have sufficient mechanical strength and chemical stability.
Static electricity and electromagnetic induction tend to cause information turbulence in magnetic storage media. The shielding can prevent static electricity from entering the inside of the device, and can also prevent the influence of electromagnetic induction on magnetic storage media such as magnetic tapes and magnetic 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 mobile classroom is not equipped with a raised floor, it is necessary to lay a static conductive floor. The conductive static ground should be adhered to the building ground with conductive glue.
However, in order to facilitate wiring, electronic classrooms are generally laid on the floor. The floor is precisely the main source of static electricity, so various types of anti-static flooring came into being, and it has been widely used in many occasions including electronic classrooms.
The anti-static floor may be made of steel, aluminum or other flame retardant materials, but the surface must not have exposed metal parts. The surface of the anti-static floor is static-conductive, and one of its important performance indicators is the system resistance. According to the "Technical Conditions for Raised Floors for Computer Room" formulated by China, the system resistance of the unit floor should conform to 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 defense. The upper limit of the electric shock resistance is to prevent static electricity from being generated due to excessive resistance.
In addition, the work surface and seat cushion material in the electronic classroom should be static conductive. Static conductive ground, anti-static floor, work surface and seat cushion must be grounded electrostatically.