PCB slotted role: For some power supply board with particularly high current, between the components of the high voltage, PCB slotted can only be used to prevent creepage distance is not enough to prevent PCB moisture leakage current increases, can be opened under the transformer holes or slots, that is to give the transformer better heat dissipation, while reducing the EMC radiation brought by distributed capacitance.
PCB board slotting purpose: PCB between the strong and weak electricity, PCB analysis material alone can also play an isolation effect, but withstand voltage is limited, although the PCB voltage is not low, but after a long time of use will be stained with dust and moisture, so its voltage will be significantly reduced, meaning that the creepage distance is reduced, creepage distance is the insulator surface staining and moisture insulation resistance is reduced, the current generated under high voltage (and even arc) The phenomenon.
PCB slotted, short distance using direct air isolation, electrical gaps, its withstand voltage will be a certain guarantee.
The best way to resist electrical strength is solid or liquid internal, such as diode PN junction, MOS tube insulation gate, in transformer oil, followed by room temperature and normal pressure or (high pressure is better) gas, the worst is the solid surface, as mentioned above, is a solid surface stained with dust and moisture.
As in the case of power transformer casing, its diameter is not large, the distance between the core column and transformer shell is not large, but because it is in transformer oil and ceramic, so it can withstand very high voltage, but the casing is quite long, the surface is made into corrugations and grooves, is to increase the distance along the surface.
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