- on Di 28 Juli 2015
Rules and guidelines for drawing good schematics
Quota from Electronics stack Exchange
Orignal article!!!
A schematic is a visual representation of a circuit. As such, its purpose is to communicate a circuit to someone else. A schematic in a special computer program for that purpose is also a machine-readable description of the circuit. This use is easy to judge in absolute terms. Either the proper formal rules for describing the circuit are followed and the circuit is correctly defined or it isn't. Since there are hard rules for that and the result can be judge by machine, this isn't the point of the discussion here. This discussion is about rules, guidelines, and suggestions for good schematics for the first purpose, which is to communicate a circuit to a human. Good and bad will be judged here in that context.
Since a schematic is to communicate information, a good schematic does this quickly, clearly, and with low chance of misunderstanding. It is necessary but far from sufficient for a schematic to be correct. If a schematic is likely to mislead a human observer, it is a bad schematic whether you can eventually show that after due deciphering it was in fact correct. The point is clarity. A technically correct but obfuscated schematic is still a bad schematic.
Some people have their own silly-ass opinions, but here are the rules (actually you'll probably notice broad agreement between experienced people on most of the important points):
- Use component designators
This is pretty much automatic with any schematic capture program, but we still often see schematics here without them. If you draw your schematic on a napkin and then scan it, make sure to add component designators. These make the circuit much easier to talk about. I have skipped over questions when schematics didn't have component designators because I didn't feel like bothering with the second 10 kΩ resistor from the left by the top pushbutton. It's a lot easier to say R1, R5, Q7, etc.
- Clean up text placement