Newbie electicity/wiring question

[MisterPresident]

I have a wallwart power supply (120v AC to 12v DC) that I need some info on. From the diagram on the label, I know the center pin is positive.

I need to know which WIRE goes to the center pin. There are two wires. One is plain black, the other is black with a white stripe. Is their any convention for polarity/stripe? If there is than I guess knowing which cable is positive or negative will tell whether it goes to the barrel or the center pin.

 

[quakefiend420]

i would guess the one with the stripe is positive...thats the way it usually works with speaker wire...but dont take my word for it...i'm not 100%

 

[NutBucket]

Need to use a voltmeter to check tho *usually* the striped wire is positive.

 

[Semidevil]

usually red is + and black is -.


so in this case, maybe striped is +

 

[YOyoYOhowsDAjello]

It's always been striped is + for me

 

[mrrman]

Originally posted by: YOyoYOhowsDAjello
It's always been striped is + for me

like he said

 

[spacejamz]

I have always been a firm believer in that if you have to ask this type of question, maybe you shouldn't be messing around with electric currents...either that or make sure the insurance is paid up...

 

[MisterPresident]

Originally posted by: spacejamz

I have always been a firm believer in that if you have to ask this type of question, maybe you shouldn't be messing around with electric currents...either that or make sure the insurance is paid up...

I'm hooking it up to a $20 device... via a 12V battery. No worries.

 

[imported_waldo]

Originally posted by: mrrman

Originally posted by: YOyoYOhowsDAjello
It's always been striped is + for me

like he said

I'll confirm!

 

[spacejamz]

Originally posted by: MisterPresident

Originally posted by: spacejamz

I have always been a firm believer in that if you have to ask this type of question, maybe you shouldn't be messing around with electric currents...either that or make sure the insurance is paid up...

I'm hooking it up to a $20 device... via a 12V battery. No worries.

are ya at least wearing rubber gloves??? 😀

 

[MisterPresident]

Thanks... It worked. I'm still alive.

 

[Bassyhead]

be careful and check, i've had striped wires on wall warts that were negative before.

 

[ktehmok]

The easiest way to find out is to plug in the wall wart, & touch each wire to a grounded surface (not the other wire). The one that sparks is the positive. Don't worry about getting shocked, it's 12v for crissakes'