Nearly 40 years have passed since the development of computer power supplies, and the power supply standards have been updated again and again, so what power supply types are available for computers from the development to the present.
The first is the standard. In fact, no matter how the PC power adapter changes to this day, it follows the power standard, so let's take a look at the power standard first.
The AT power supply standard was formulated by IBM, and the power consumption of computers in the AT power era was generally low, so the output of the AT power supply is not very large, generally 220W is at the top. Moreover, the old AT power supply only supports +12V and +5V output, and the AT power supply cannot be switched on and off at will like our current power supply type. Instead, a special mechanical switch is required to switch the power supply. Our current power supply is controlled by +5VSB detection to control PS-ON and PS-OFF, but the size of the power supply is the same as today's power supply, both are 150mm*140mm*86mm.
It can be said that all PC power supplies, such as desktop PC power supply, accessible to ordinary users belong to the ATX specification. There have been several versions of the ATX power supply specification from the first edition to now. The ATX power supply mainly has two major stages: P4 and before P4. The version before P4 is up to ATX2.03, but compared to the first version of ATX1.0, these versions have no changes.
But with the release of P4, CPU power consumption has skyrocketed. It is no longer possible to support CPU power consumption by relying solely on motherboard power supply. So from this time, the ATX power supply specification has ushered in a big update: ATX 12V, which has an extra 4pin compared to the old version The CPU power supply socket. That is the type of P4 power supply we often say. The later updated specifications added the SATA interface, and the 20pin motherboard changed to 24pin.
The BTX power supply has been mentioned here, and its root is still ATX, mainly for compatibility with BTX motherboards. The specifications it follows are derived from ATX, and BTX is not a product of standard specifications after all, so we rarely see the power supply type of BTX.