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What is power rail

electronicsLearner77

Jul 2, 2015
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Generally we use the term power supply, but sometimes i also see the term power rail being used. What is the difference? When should i say power rail and when power supply?
 

Harald Kapp

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Power supply is the source of power: battery, wall wart, benchtop supply, you name it.
Power rail is, simply speaking, the name for the wire feeding power to a circuit. Also the trace on a pcb or a length of massive conductor resembling a "rail" (my guess: that's where the name comes from).
 

davenn

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Generally we use the term power supply, but sometimes i also see the term power rail being used. What is the difference? When should i say power rail and when power supply?


hi ya
Power supply is where the power is coming from eg battery, plugpack variable PSU etc

Power rail(s) are the positive and negative and or zero volt lines in a circuit eg .....

upload_2021-1-17_19-6-41.png

In the above PSU circuit there are 3 output rails, + 12V, Ground = 0V and -12V that go to the circuitry

In a 2 rail circuit, there may be, say, a +12V rail and a 0V rail ( Ground or battery/PSU negative)


Dave
 

ratstar

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Do they call it a rail - because it supplies all the parallel connections to the circuit?
(in a bar type form, on the top and the bottom, im talking about.)
 
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