What is the cause of electricity on the body of the computer case?
This electric shock or case of the case body may have happened to you when you touch the metal body of the refrigerator, TV, or other household appliances.
Now a few questions may arise:
- What is this electricity? Where does it come from and what is the reason for its existence?
- Is this electricity dangerous and could it harm my health?
- What is the solution to reduce the amount of electricity on the body of the case?
First of all, you may be wondering why the body of the case should be conductive at all! The CE standard is the standard of health and protection of human life. According to the CE standard, which is a European standard and its provisions are observed and reviewed by the Iranian Standards Organization, all grounds must be integrated into a computer system and the conductive body of the case is responsible for this. Yes, when you screw your graphics card, CD-ROM, hard drive, motherboard, and power supply to the body of the case, you are basically merging the grand components together. Finally, if there is a connection in the system, it will be transferred to the power supply through these same ground and will be transferred to the ground connection pin (earth) by this wire to save your life.
In most electrical appliances that have an electric motor or switching power supply, we have a phenomenon called EMI, which stands for Electromagnetic Interference, which in Persian is also called electromagnetic interference.
Electromagnetic interference, or EMI, occurs in two general forms:
- In the form of radiation emitted by electronic devices
- It flows inside the conductor wire and body
Normally, when someone in your building's electrical circuit uses a welding machine, hairdryer, water pump, ventilator, and the like, you will have EMI harmonics inside the building's electrical wiring. In the input section, there are standard circuit power supplies called EMI, which form an EMI Filtering circuit through two types of capacitors, X and Y, to prevent electromagnetic interference from entering the power supply. On the other hand, your power supply itself is a switching power supply. , Is considered as a kind of producer of these interactions. So again, there is a need for an EMI Filtering circuit to prevent these interferences from leaving and entering the electrical circuit of your building.
The function of capacitor X is to repel interferences between phase and zero, and the function of capacitor Y is to repel interferences between ground (GND) and phase and ground and zero, so a base of capacitor Y is connected to pin inheritance until this extra current is added by the third pin. Transfer power and power cable to your earth well. wait! The house or place of the cartoon has no well! So where will these electromagnetic interactions go? In principle, these harmonics will not find a place to discharge and will flow on the body of the case. In fact, when you touch the body of the case, your body transports it to the ground.
Now, if you are on the ground with your bare feet, there is a lot of EMI interference inside the electrical circuit of your house or cartoon place, this electric shock will be more noticeable for you! Therefore, in some seasons or certain hours of the day, this feeling may be more or less. Do some ask why this power supply is not felt in low-quality and cheap power cases and cases? The body of low-cost cases does not have high conductivity, and more importantly, the non-standard power supply does not have an EMI Filtering section at the input to transmit these interactions to the ground.