How to connect an IP camera over twisted pair?

Question

Cables and wires

I want to connect a camera as in this article
There is a network cable

There is a camera

Well, a power supply.
Which in this example should be connected to the camera wires to the network wire?

Answer 1

more

Answer 2

According to the link to the article, its author uses a four-pair cable for some kind of "passive PoE", using two pairs to power the camera at a short distance (at a current of 0.5-1A and a voltage of 12V on a long AWG24 cable (0.4 squares per two conductors) pure copper, and even more so AWG26 bimetal (copper-plated aluminum and, moreover, copper-plated steel), which are most often bought by "thrifty" people, 10V or less will come to the camera from 12V, which will not be enough for its normal operation). You have a two-pair cable in the photo, that is, the power will have to be supplied separately, laying another cable in parallel (for example, ~ 220V to power the PSU installed next to the camera, if the link is more than 20-30 m). If you want to connect, as in the article, you will have to use a four-pair high-quality cable with a short distance to the camera.
As for the article itself: judging by the photo, the author has a camera with PoE IEEE 802.3af and it is reasonable to power it from a separate PoE injector or switch with PoE power on the ports, while using power with a nominal voltage of 48V, where a drop on a long wire of several volts is not critical.
Of course, when installing one or two cameras and the ability to install a PSU nearby, or powering over free pairs of an Ethernet cable at a distance of several meters, you can save on an injector or a special switch, but with professional installation of a video surveillance system, such a "collective farm" should be avoided.