# Possible ways to represent a circuit schematic

I have the following circuit with a 9V battery and two resistors, R1, R2, in parallel. Here is how it looks:

Are the following three ways all valid ways to represent this circuit?

Explanation:

• In the schematic, current flow is shown, which is always positive to negative.
• In #2 I've basically removed the negative terminal of the battery and put it at the bottom of the schematic.
• In #3, I've moved the negative side to the right of the diagram and smoothed out the lines, so it looks more like a graph/loop and less like a schematic.

If #3 is a valid way to depict circuits (which for me is the simplest to understand intuitively), what are some resources that show how to decompose a circuit into that?

• #3 is not valid, because it is unclear what the two terminal components on left and on right actually are Jan 29, 2020 at 23:37
• if #3 is the way that you would like to draw the schematic, then how would you draw 15 parallel resistors? Jan 29, 2020 at 23:39
• perhaps you could try to figure out why you find #1 more confusing than #3 Jan 29, 2020 at 23:40
• David, if you are asking us to help you find resources that will prove your intuitions are correct and provide follow-up material on "decomposing" circuits using your imagined methodology, then I don't think that is likely to happen. If you feel you have a correct intuition, it is your job to document why it is valid and then to show others how to apply your way of thinking about the world in a way that is convincing and thorough. No one else has any obligation whatsoever to take your ideas and spend their time on your ideas for you. You might wish otherwise. But people value their time too.
– jonk
Jan 29, 2020 at 23:43
• I don't know what you mean by valid, but all three are equally bad.
– Chu
Jan 30, 2020 at 1:17

You would also not use giant circles with +/- inside them. You would use commonly understood symbols. A tiny circle with a +/- beside it on the outside is fine. It makes it clear it is just a pin, and not a component unto itself. The large circles with +/- makes it look like it is its own component.

For #2, you would normally put the + at very top instead of to the side. For readability and consistency.

#3 has the problem that the large circles with +/- inside makes it look like its own component. With multiple wires running straight out of the circle, all of which are unlabelled, it is not clear if these are different connections or multiple connections to the same point.

#1 only really has the problem that the battery symbol is not standard but it's easy enough to figure out what it is supposed to be when drawn like that: One component, with two clearly labelled terminals + and -.

Curved lines for the sake of being curved also does not work for more complex circuits multiple loops, or 3-way, 4-way, or n-way intersections. Or long lines that must drop off at different locations. In larger circuits, it's very important that your eyes easily follow where things are going which won't be the case with arbitrarily curved lines that sway back and forth everywhere in a non-uniform manner. How would you draw this circuit with curved lines?

simulate this circuit – Schematic created using CircuitLab

• @David542 I was editing my post after copying and pasting into the comments and you probably saw it before it was fixed. Jan 29, 2020 at 23:58
• @David542 I did add a cap afterwards. But your circuit now is nearly unreadable. Different components now all look the same and can't be differentiated at a glance, different sections of the circuit are no longer distinct, there is no flow to reading the circuit, and everything is in a big mush. There's no beginning and no end. Jan 30, 2020 at 0:14
• got it, thanks for your answer an explanation. It's very helpful and illustrative. Additionally, I got the big pluses from "Make Electronics", where they do stuff like this: imgur.com/a/9o1BPXX Jan 30, 2020 at 0:18
• @David542 Ah. Well, print can do things we can't do by hand like italics. If you made the circles much much tinier relative to components then you could probably get away with it for voltage terminals. But you probably make the circles so big because are making multiple connections to them which is part of the problem (it makes them look like entire components with multiple unlabelled pins). That's why we run a single line out from a pin and then split it up outside if it needs to go to multiple places. Remember that processors with dozens or hundreds of pins are in schematics too. Jan 30, 2020 at 0:23
• @David542 The main difference is that one provides power and ones provides information. In reality they both provide some voltage and some current, but the power supply provides "large" amounts of voltage and current which carry no information. They just power the circuit. The signal supply (bad wording, it should be the signal source), produces a signal that carries information but usually very little power (some voltage, almost no current) and "controls" the circuit rather than powers it. Jan 30, 2020 at 0:29

If you are determined to break up the battery then you should use one of the following ways. It is fine to try to rearrange a schematic in order to help you understand the circuit better but there is a point at which you go too far.

For example when you have two terminal (+) and (-), then you place them like I demonstrate in my first schematic. I have never seen them placed far away. If you want to do that, then you should use one of the other two schematics I provide, so the (-) terminal becomes the ground.

Something else to keep in mind is that (+) and (-) go in pair as to create a voltage difference, so there would be no reason to separate them because it actually makes it more difficult to understand what element has what voltage. Your circuit is elementary but imagine the confusion if in a huge circuit you had to search and combine (+) and (-) from all over the place.

Also keep in mind that the point of a schematic is also to communicate information between different people so it is better to stick to standard notation.

simulate this circuit – Schematic created using CircuitLab