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Some people compare the CPU to the "heart" of the computer. In fact, if we really compare it, the CPU is more like a brain for the computer, and the heart that really powers the computer should be enough power for the computer. power supply. So let's take a look at this corner that we have neglected.

PC power has been in development for nearly 20 years since its inception. During this period, there have been many changes in power supply shape, output voltage and power, and electrical performance requirements. Many different specifications and standards have appeared. There are still many types of power supplies coexisting on the market today. Different types of power supplies are designed for different types of mainframes, so it is necessary to correctly distinguish the type of power supply.

IBM PC/XT/AT is the earliest industry standard for PC power supply. The popularity of the compatible machine concept makes the PC power supply have a relatively uniform design. It also establishes a power bus with four output voltages of +5V, +12V, -5V, and -12V. Architecture. The +5V is responsible for the power supply of almost all logic chips to meet the industry standard +5V TTL logic level requirements, while the +12V is mainly for the internal hard drive and optical drive motor. The connection between the AT power supply and the main board is two single-row 6-core lines, which are P8 and P9 respectively. The most obvious sign of the appearance of the AT power supply is its AC input switch line. Due to the safety requirements of the AC input line, the cable has a thick insulating sheath and is easily identifiable.

The emergence of ATX power supplies is a major change in PC power. A +3.3V main output has been added to the ATX power supply, and the +5VSB standby output and PS_ON# signal have been added. +3.3V is designed for parts with lower power consumption and lower logic voltage. The increase of +5VSB and PS_ON# is to meet the needs of PC's new power management solutions such as remote switch and keyboard switch. The output cable of the power connection main board is also expanded from the original 12-core to 20-core, and a double-row 20-pin plug is used. Design specifications for PC power supplies have also been established and improved, typically the industry-accepted Intel ATX Power Supply Design Guide and SFX Power Supply Design Guide. These two standards are still the most important reference in PC power supply design.

The P4 power supply is currently the type of power supply that is of concern. Its official name is the ATX12V power supply. When Intel introduced its next-generation Pentium 4 CPU, it also proposed a power standard that is compatible with system changes, namely the ATX/ATX12V Power Supply Design Guide. "ATX12V" is used as the "Advanced Series" in the ATX series of power supplies. Compared with ATX, the ATX12V power supply has the following two significant changes:

1. Increase the +12V output capability. CPU, Chipset, etc. on the motherboard have their own specific operating voltage, which needs to be dependent on VRM or local DC/DC. As the IC power rises, using +12V to power these parts is better than using +5V or +3.3V. Easy to transfer more power and have higher transmission efficiency.

2. Added +12V output cable and connector. In order to make the current of +12V transmit well, a 4-pin +12V connector is added, which also becomes the appearance feature of the ATX12V power supply.

In addition, another change in the ATX/ATX12V series power supply is the increase in +5VSB output current due to power management schemes such as "Instantly Available PC" and "Suspend-to-RAM".

Common types of PC power supplies are listed.

The most common type on the market is the standard AT/ATX ATX and ATX12V power supplies. The power supply is mostly between 200W and 300W. We can select them according to the needs of different hosts.