Hi there. I'm fairly new to reading schematics and am confused by one thing right now: What does it mean when you see one wire connecting into another wire on a circuit diagram?
(See the attached example, with crossing red wires.)
Thanks in advance for any help you can give!
Mainly it means that someone couldn't be bothered to draw a proper schematic and instead delivered one of those stupid Fritzing things and there are no real rules for them.
Crossing wires probably just means it's two separate wires and no connection between them. In the case where two red wires do not CROSS but just butt up against one another it VERY LIKELY means they are joined together. But again THERE ARE NO RULES so it means whatever the person who drew the thing intended it to mean. (And that's only one of the reasons why most experienced people here detest those Fritzy things).
Steve
I'm glad you didn't call that a schematic. Oh wait... You did... That's not a schematic... that's a fritzing picture. These make a lot of people unhappy.
The normal SCHEMATIC way of showing that the wires are not just crossing but also "joined" is with a circular DOT at the joint of the wires. If there is no DOT, they are not joined.
A good schematic avoids ambiguity by never having a 4-way joint, only 3-way ones:
Once a circuit diagram has been scanned, scaled, printed, rescanned etc the dots marking the
joins may be illegible - the only-join-3 rule finesses the issue completely.
MarkT:
A good schematic avoids ambiguity by never having a 4-way joint, only 3-way ones:
Once a circuit diagram has been scanned, scaled, printed, rescanned etc the dots marking the
joins may be illegible - the only-join-3 rule finesses the issue completely.
Many modern schematic programs have a menu option where dots can be added by the program.
Note: To tell the program there is a connection at a X crossing point you simply draw ‘up to’ a perpendicular line, click, then continue drawing in the same direction.
The automatic placement of a connection dot will then be placed at the above point.
You always have the option of placing a dot manually.
So things are not ambiguous, always use ‘dot connections’ in your schematics.
There are three conventions you can use to denote wires crossing. Which one you choose determines how you must show the joints.
My preference is to use B.
As others have pointed out you are not posting a schematic but a physical layout diagram. There are useless for conveying what a circuit is. There only use is for someone to blindly follow the wiring to construct it, without having any understanding about what is going on.
They are very often a lot more complex than a schematic. I have to make physical layout diagrams when I publish stuff as publishers insist on them but I never use fritzing as it is apile of crap and doesn't produce very good wiring. Also they are based around solderless bread boards which are also crap except for the most trivial and temporary circuits. I have seen many people exhibiting at shows hunched over a solderless bread board rocking the wires in an attempt to get their project working. Many have to give up and go home. Soldering a project on strip board is the answer.
Here is an example of a schematic v a physical layout diagram. Note how much more complex the physical layout diagram is and it does not convey anything about how the circuit works.
Note here the convention I use is that the conducting copper strips are shown as if you were looking through the board. They are actually on the other side but you have to be aware of where they are when soldering up a board. Also I make sure that wires of different colours are the only ones that cross and that indicates they cross. The only joints are through the copper strips.
