wall wart polarity

[buck1s]

I've noticed that on a couple of wall warts that I purchased recently there is a dark colored stripe on one of the wires. Is this typical? Does it tell polarity? Thanks guys.

Chris

[pkoslow]

I don't know if there is any true "standard" to this, but in my experience the striped wire is usually 'positive'.

Paul

[smoothtlk]

After wiring a jack from a wallwart, I always check with a multimeter before plugging into a device (DC outputs only).

[Chas821]

Checking with a meter is the best way to determine polarity. The stripe on the wire might very well be the positive lead from the wall wart, but if the plug at the end is molded, then there is no way to determine which wire is connected to the barrel and which is on the female connection. If there is no plug at the end (just wire) measure anyway. I don't believe there are standards. Remember; most of these are manufactured overseas where QC is pretty low.


Chuck