CCTV Power Jack Adapter Wiring Standard

[cglaeser 0]

Is there a wiring standard for 12 VDC power plugs? Should the outside conductor be plus, minus, or there is no standard and could be either?

 

See http://www.amazon.com/2-1mm-5-5mm-Female-Power-Adapter/dp/B003MHUN7S/ref=sr_1_2?tag=gpse-20&ie=UTF8&qid=1292217153&sr=8-2

 

Best,

Christopher

[Soundy 1]

There is no written-in-stone power-jack standard for pretty much ANY electronics... but with 12V barrel connectors, the vast majority of cameras seem to use tip-positive configuration (offhand I can't think of a single exception that I've come across).

 

I have seen ONE exception with some computer speakers I have, that use tip-negative... and I have an old Wacom drawing tablet that uses tip-negative (so old, it has a 9-pin serial connection). Most devices seem to be tip-positive though. There will usually be a diagram ON the device showing which polarity it uses.

 

[bpzle 0]

All cctv cameras and cctv power suppliers I've used with barrel plugs, the outside of the plug is negative. The wire with a white stripe is positive.

[Soundy 1]

All cctv cameras and cctv power suppliers I've used with barrel plugs, the outside of the plug is negative. The wire with a white stripe is positive.

Be careful with this, now, because this is a function of the power supply itself, not the camera, and can vary from one to the next. I just recently had to rig up a power supply and the only one I had, had no barrel plug... so I found another barrel plug (recovered from a removed camera), and found that while the plug connected the white wire to the outside of the barrel, the power supply itself used the white-striped wire for positive (and the diagram on it showed it was originally a tip-positive unit).

 

If you're splicing new barrels in, or snipping one off to just use the bare wires out of the wall-wart, always double-check polarity with your multimeter!

[hardwired 0]

All cctv cameras and cctv power suppliers I've used with barrel plugs, the outside of the plug is negative. The wire with a white stripe is positive.

Be careful with this, now, because this is a function of the power supply itself, not the camera, and can vary from one to the next. I just recently had to rig up a power supply and the only one I had, had no barrel plug... so I found another barrel plug (recovered from a removed camera), and found that while the plug connected the white wire to the outside of the barrel, the power supply itself used the white-striped wire for positive (and the diagram on it showed it was originally a tip-positive unit).

 

If you're splicing new barrels in, or snipping one off to just use the bare wires out of the wall-wart, always double-check polarity with your multimeter!

 

+1, a number of wall warts I have come across have used the white stripe lead for negative, always check with a meter before you toast something expensive (some wall warts have ridiculously high unloaded/lightly loaded voltages, too, if you are using a very low current draw device, you could go outside it's voltage limits).