Author Topic: Beginners guide to Wiring Diagrams...  (Read 863 times)

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Marty Machine

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Beginners guide to Wiring Diagrams...
« on: April 20, 2009, 10:03:39 PM »
Beginners guide to Wiring Diagrams...

Many people are confused by reading circuit (schematic) diagrams.
Here's some basic pointers to assist.

Here's some wiring standards used in diagrams old & new.

Diagram A - 2 supply voltage lines pass eachother - they do NOT connect!
Diagram B - 2 supply voltage lines pass eachother - the 'hump' shows they also do NOT connect!
Diagram C - 2 intersecting lines ARE joined, so all lines now carry +12v on them - older style diagram.
Diagram D - 2 intersecting lines ARE joined, so all lines now carry +12v on them - Modern style diagram.



Here's a fairly common style of wiring diagram, where wiring can come from from all sorts of chips and connectors
to merge into one device - usually lines end up crossing over eachother, and it becomes hard to determine
"which way" is the voltage (or signal) now travelling along.
This seems to catch EVERYONE out from time to time ;-)

This diagram shows a binary counting chip at the left (yellow box), sending it's information into a large 'AND' gate.
Also underneath is a single "Invertor" chip. (don't worry about trying to understand how this circuit works).

Looking at the +5v supply at the top, it feeds straight down into pin 11 of the 'AND' gate.
How do i know it's NOT also going into pin 5 or 6 of the AND gate, or even pins 4 or 5 of the Binary counter chip ??

My simple rule is :
FOLLOW the Horizontal (or Vertical) line as it leaves the component.
Always follow the line across other lines, and continue along until you come to a "Bend" or until
you arrive at a pin of another component.

This determines the destination of the line, while crossing over all other lines.
The ONLY time to change directions is when you come to a bend, then follow THAT direction to it's destination.

Also, Refer to the above diagram, to see that NONE of the lines have any joins.




Hope this super-quick guides helps out, and feel free to post some diagrams here that are causing you confusion.
MM.
« Last Edit: April 23, 2014, 11:25:42 PM by Marty Machine »