The following diagram shows a voltage regulator that gets two inputs (+-24V) and generates two outputs (+-15V). For this reason, I am representing the 15V signals as outputs, but I don't know if this is right or not.

Below, there is another regulator, which uses a 15V supply. Should I use an input sign, to keep the same logic as above, or in this way is right?

enter image description here

I study control and automation engineering, and so far I have a bit of difficulty to standardize my schematics, as it looks like every schematic I see is different from one another. Any thoughts on that are appreciated as well...

  • \$\begingroup\$ You've got one (?) power block dedicated to power conditioning, which is a normal situation for a lot of schematics. \$\endgroup\$ Jan 3 '17 at 20:46
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    \$\begingroup\$ I've got no problem with your schematic, except that I would put the bottom symbol on the top as well - i.e. have both symbols as one represents the output from the block, and the other represents an internal connection within the block. \$\endgroup\$ Jan 3 '17 at 21:48
  • \$\begingroup\$ By "the other", what exactly do you mean, Tom? \$\endgroup\$ Jan 3 '17 at 23:27

Input and output declarations typically imply signals -- be they analog or digital. Examples include the input/output of a logic gate, an audio amplifier, or a microcontroller. Power nets (e.g. +15V, +Vcc, -Vss, etc.) are typically depicted as isolated net labels or rails -- horizontal lines above (for positive) or below (for negative) the circuit:



I would suggest using this notation in your schematics -- the second circle in your image. That way it may be easier for you to read since you can quickly discern signals from power rails, and it may be easier for others to read, too.

  • \$\begingroup\$ On the "easy to read" part: do you agree that the first circle is, in a way, the output of the regulator? I thought the readability would maybe suffer if I used the notation on the second circle, as it could, at a first glance, imply a 15V "input", and in my head this "flow of power" helps to read the thing. But again, I am not very confident about how to write it on a schematic... \$\endgroup\$ Jan 3 '17 at 23:24
  • \$\begingroup\$ Like I said, the input/output scheme generally implies signals, so the +/-15V output may rub some people the wrong way (as in a small annoyance -- most will know what you're getting at). Though input power and output power are common terms -- especially in these voltage conversion circuits -- the idea of power as a signal isn't as common in these applications. Power rails are treated more like omnipresent references like ground. \$\endgroup\$ Jan 3 '17 at 23:52

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