Evolution of Power PCB Design
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o-leading.com
2018-04-28 10:01:28
EMI filtering
The role of the EMI filtering system in the power supply is to filter out the impurities in the mains, so that the input current is more pure and does not interfere with the hardware work. In general, a normal power supply will have one or two EMI filters. Some power supplies will filter the primary EMI on the input power pins, and the power supply on the above figure will be on the PCB.
Rectifier bridge
After the current is filtered, it enters the PFC, first through the rectifier bridge, and the rectifier bridge converts the alternating current into direct current. In general, the rectifier bridge will have a lot of heat during operation. The excellent power supply design will lock the rectifier bridge to the heat sink. It is unreasonable to design two rectifier bridges directly on the PCB board like the Patriot E-sports 500. .
PFC
The current flowing from the rectifier bridge enters the PFC. PFC is the abbreviation of Power Factor Correction. The translation is power factor correction. The AC power is wavy, and the PFC power supply can be used not only for peaks and valleys but also for power utilization to increase utilization.
The role of the main capacitor (PFC capacitor) in the power supply: First, the filter, and second, the storage of electricity to ensure a sudden power off when there is a certain amount of power to support computer hardware to respond.
The next step is the transformer system, which is generally divided into size transformers and step down the mains to fit the host. The larger one in the figure is the main transformer.
Rectification, regulation, filtering
Transformer out of the current through a rectification into a direct current, and then regulated filter before output to the computer's hardware.