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What do different color wire mean?

AndreeU17

Apr 23, 2014
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Hello, I'm new to this forum as well as to really digging into the details of electronics. I've always had small ideas and tops here and there but now im hoping to really understand what electronics is capable of and how it all works.

Anyways, I've disassemble a group of electronics only to find out their hooked up (Soldered) using a plethora of different color wires. I Understand that Black Wire (Ground), Red Wire (Power), Yellow Wire (Video) & White Wire (Audio) But what about other cables? Are other colors simply POWER or are they all POWER besides Black (Ground)? What about Jumper Wires? Jumper Wires are numerous of different color wires, Do each color provide a different function or are they all Power and the PCB make it do certain thing? Also can i simply create myself a stack of Jumper Wire using Red Wire (POWER)? Apart from that what is the purpose of Jumper Wire?

Hopefully these are simple questions and hopefully someone here can help! Please bear in mind im a bit of a beginner, try explaining in a simpler way and/or try not disrespecting my understanding (Bad experience in other forum)

Thank You
-Jonathan
 

KrisBlueNZ

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There are no rules about wire colours, only conventions.

The simplest rule is "black is negative, red is positive".

Black is normally used for the 0V ("zero volt") rail of a device. Almost every non-trivial circuit has a 0V rail; it is the reference point for supply voltages, control voltages, and signals; that is, those things are all measured "with respect to" 0V. 0V is sometimes called GND or ground, but it's not always grounded, so that name can be slightly misleading.

Red is normally used for positive supply rails; orange is also sometimes used.

Blue can be used for negative rails (negative relative to 0V). Not all circuits have such a rail though.

Green is often used for ground in mains-powered circuits and circuits where ground is different from 0V.

As you say, yellow could be used for video, and white and red for audio, though I've only ever seen this convention used for the colour of the RCA phono plugs and sockets, not for actual wires.

Some interfaces have standard wire colours - for example, AC mains power cables (where cable colours are VERY important), USB cables, Ethernet cables, etc.

Other colours are used for all kinds of signals, without much standardisation.

Occasionally, wires are coloured to match the resistor colour code system. For example, an 8-wire digital data bus could use black, brown, red, orange, yellow, green, blue and violet for bits 0~7.

Regarding jumper wires for prototyping using a breadboard, I would stick with standard usage for red and black, and blue if you're working with negative supplies, but have a collection of random other colours for other types of signals. You can create your own conventions for circuits of different types. For example, white for audio signals, grey for control signals... whatever helps you the most.
 

shrtrnd

Jan 15, 2010
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To add to KrisBlueNZ's input:
Some manufacturers try to stick to generally accepted color-coded wires for specific functions.
I'm believing from your question, that you're surprised to open a device up and see many different colored wires. And are wondering why.
Those multi-colors help ensure for the manufacturer, that their devices get assembled in the factory correctly, and that if service is required, generally, what their techs should look for in the wiring of the device to trace circuit issues.
While KrisBlueNZ gave you a good run-down of generally accepted color-coding (which is especially prevelant in the external wiring of consumer electronics, for connecting audio/video devices);
The INTERNAL wiring of devices is often completely up to the manufacturer, for their own edification.
Don't expect to open something up from one company, and expect a competitor, to wire the various sections of their equipment using the same color-coding of the wires.
If you have a specific wiring issue you want to ask about, people will try to help you here.
 

AndreeU17

Apr 23, 2014
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There are no rules about wire colours, only conventions.

The simplest rule is "black is negative, red is positive".

Black is normally used for the 0V ("zero volt") rail of a device. Almost every non-trivial circuit has a 0V rail; it is the reference point for supply voltages, control voltages, and signals; that is, those things are all measured "with respect to" 0V. 0V is sometimes called GND or ground, but it's not always grounded, so that name can be slightly misleading.

Red is normally used for positive supply rails; orange is also sometimes used.

Blue can be used for negative rails (negative relative to 0V). Not all circuits have such a rail though.

Green is often used for ground in mains-powered circuits and circuits where ground is different from 0V.

As you say, yellow could be used for video, and white and red for audio, though I've only ever seen this convention used for the colour of the RCA phono plugs and sockets, not for actual wires.

Some interfaces have standard wire colours - for example, AC mains power cables (where cable colours are VERY important), USB cables, Ethernet cables, etc.

Other colours are used for all kinds of signals, without much standardisation.

Occasionally, wires are coloured to match the resistor colour code system. For example, an 8-wire digital data bus could use black, brown, red, orange, yellow, green, blue and violet for bits 0~7.

Regarding jumper wires for prototyping using a breadboard, I would stick with standard usage for red and black, and blue if you're working with negative supplies, but have a collection of random other colours for other types of signals. You can create your own conventions for circuits of different types. For example, white for audio signals, grey for control signals... whatever helps you the most.


Yes i somewhat understand, its still a bit misleading and confusing but nothing that few practice can improve. I'm currently dealing with circuit wiring such as a Nintendo 64. Here an image (Hope You can see it)
http://cdn.instructables.com/FU4/MJ2L/GG4A6O7M/FU4MJ2LGG4A6O7M.LARGE.jpg

As you can see in the image, there is multiple color wire! How do i know which wire must be use? Must i go to Radio Shack and buy those color wires ? As of right now all i got is RED & BLACK wire! I understand what the points are in the motherboard PCB, etc but what really tumbles me is the color wiring. The above user mention that manufacturers simply color code the wiring for an easier troubleshooting case. Also to determine whether its their product or not according to what i read. If i'm not in the right set of mine, please bear with me! I get confused in these topics (My professeur hasn't gone over this, I want to improve before we go over topic)!
 

davenn

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Read again the 2 previous post
Other than red and black (sometimes green) for positive and negative .... the rest of the colours used are totally random
The manufacturers use whatever colour they like. You could replace every other colour wire with a white one if you wanted to. It wont affect the operation of the circuit

Dave
 

AndreeU17

Apr 23, 2014
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Read again the 2 previous post
Other than red and black (sometimes green) for positive and negative .... the rest of the colours used are totally random
The manufacturers use whatever colour they like. You could replace every other colour wire with a white one if you wanted to. It wont affect the operation of the circuit

Dave
Okay yeah that makes sense, i just tend to second guess myself and rethink things. But alrighty then, So are all the Other Color Cables simple POWER cables like the red one? If thats the case then i'll simply Used Red Cable for Power and color them in with a Sharpie, and use Black For Ground!

Thanks !
 

davenn

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But alrighty then, So are all the Other Colour Cables simple POWER cables

NO, why would you think that ?

they could be data lines, audio or video lines, anything at all

sometimes you find that they may use red for the main input power line, then use a different colour to denote a regulated lower voltage line

Dave
 

KrisBlueNZ

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I think the person who drew up that wiring diagram just used different colours for the wires so you could follow them easily on the diagram. You can use different colours if you want - the colour of the insulation doesn't affect the behaviour of the wire, obviously. But if you use the same colours as the diagram, you might find it easier to check that everything is wired correctly.
 

daddles

Jun 10, 2011
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Unless you have a correct schematic for a device, never assume that a particular wire color means anything inside a device -- sooner or later you will get bitten. And there are even two exceptions to that rule: the drawing can be in error or a production person was rushed to get a product out and they were out of a particular wire color, so they substituted another color. The chronologically-gifted have often seen all of these things.
 
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