Instructables

Is there a positive and negative wire in the three pong computer desktop power cord?


Only if it is plugged into an outlet that supplies DC, in which case you would need to use a test device to determine the polarity of the wires. If the cord is to be plugged into a standard AC outlet, see the color code explanations elsewhere in these answers, but it is AC current , not DC. If you are just using the wire without plugging into an outlet (plug cut off), then I suggest using caarnted's color listing as it is industry standard, which will help keep confusion at bay.

(Please don't play with mains power - that which comes from a wall AC outlet - as it can kill, especially if you really don't know what you are doing with it.)

Qa
canucksgirl2 years ago
Absolutely. One prong is attached to a positive wire. The second is to a negative wire and the 3rd (center) is your ground wire.
scooter2013 (author)  canucksgirl2 years ago
Do you know which color? There isn't a red and black wire in this cord. I just want to scrape the wire for a LED project.
Hot/active/live/positive = brown or red. Neutral/return/negative =blue or black. Ground/earth = green or green and yellow.
Hot is not positive!  It is a supply that is alternately positive and negative.
Neutral is not negative.


Continuing to use positive and negative with a/c is just continuing the confusion.
I'm just using his terminology to say which colour is used for what. For all we know he wants to use the power lead from his P.C. to wire a car stereo to a battery in his garage. Colours aren't posive or negative or hot or anything else until somebody connects them up.
*positive
Ha ha! It took me a minute. Thanks :D
lol.... I figured you'd catch on sooner or later... :D
If you just want to use the scrap wire, then it doesn't make any difference. Wire used for + is no different than that used for -, although depending on your project, AC cord might be a rather heavy gauge. It shouldn't make a difference, though.
@Canucksgirl. No, there isn't. This is AC, there is no positive/negative arrangement. There is a hot, return, and ground.
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Your right.

You're.
Ok thanks.
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caarntedd2 years ago
No. One is active/live/hot. The second is neutral/return. The power outlets in your home should supply an alternating (AC) current. Positive and negative usually refers to direct (DC) current. The third is ground/earth. Swapping the active and neutral in this case won't make any difference as long as you don't swap one or the other with the ground. This happens all the time when people make their own extension leads or replace plugs on appliances and accidentally swap active and neutral. Not recommended but should not harm your computer.
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