rewiring an ac adapter/charger 19.5vlt for a laptop
Use a voltmeter. Standard colors depend on make and year.
Rewiring for what ?
Uh, what' cha workin on there. Without knowin what you have there is no way to tell which is which. maybe it's a/c so there is no pos. or neg. Not every thing is wired to the standard even where there is a standard.
In Australia it is as steve says, on mains power (for appliances and extension cords) brown is live or active, blue is neutral. The fixed wiring in our houses is red and black. Are you connecting to mains power? Brown = red, and blue = black.
US AC mains power... Black is the Hot side fuse protected wire, White is the neutral wire, Green is building SOLID copper pipe into the Ground wire. Red is another Hot phase fuse protected wire.In Electronics ... Red is the positive +DC fused wire, Black is the zero voltage wire, Green is the enclosure frame ground wire Green is the same as the AC Mains green when a TR power supply is present.. Blue and yellow get used for -12VDC and +12VDC Orange can be another +DC Voltage Brown, white, violet have no specific designations in my lexicon. . Dual gray wires are low voltage AC. A
On MAINS AC, Brown is LIVE Blue is NEUTRAL. Like Re-des says there is NO "Positive" on AC.
In the US green is neutral, blue is low voltage dc, I don't know what brown is.
Is that a standard ? I don't remember my NEC....
I know the green is, but the other came out of an older book.