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本帖最后由 Aubrey 于 2018-3-13 16:20 编辑
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指的是电路中各电源电压在不同对应状态下的电压。# \* R# a( q+ ]4 i
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What Is a Power Supply Rail?* M% _0 s0 U; ]2 |7 z* A0 M$ b
A power supply rail is a supply voltage that is provides power for electrical or electronic devices or components on a circuit board. Power supply rails used for early desktop computers included +/–5 volts (V) as direct current (DC), +/– 12 volts direct current (VDC), and a common or return line. Later, computers began using +5 V and +3 VDC for the rails. The power supply rail used for most analog circuits still requires a split power rail. Operational amplifiers may use a +/–12 V power supply rail, and they operate with input and output signals that are typically dual polarity in nature similar to the sine waves or sinusoidal waves, which have alternating polarity like alternating current (AC). The voltage rail in a power supply unit will have a corresponding current limit. Power supplies with an absolute maximum rating of 10 amperes (A) may be operated at 90% full current, which is 9 A. If the load requires 18 A, two power supplies will need to be used. Manufacturers may provide special instructions when connecting two power supplies to drive the same power supply rail. There are also cases where the load has been split to provide the proper loading to each power supply.
_' Q# j! C7 z A short history of PC power supply voltage rails7 P. h, t: o- S# ]
http://www.playtool.com/pages/psurailhistory/rails.html% B {$ ^) W/ r) K5 y' E7 V. y
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