DIY PoE, is it real?

Question

Do it yourself

There is an IP video camera with PoE support according to the IEEE 802.3af standard, and the need to connect it with one cable. Is it possible to do this without buying expensive PoE-enabled equipment?
The only option that comes to mind is Passive PoE, since the camera has the possibility of a separate power connection.

Answer 1

No, it's not that easy to do. If you want, look at the datasheet on the microcircuit on which the injector is made + you need an isolation transformer + 48 volt power supply.
If you only have one camera, buy a single injector like this tplink www.tp-linkru.com/products/details/?model=TL-POE150S , I think it's cheaper than developing it yourself, and even for one time.
Or here the naga has shop.nag.ru/catalog/14787.POE-inzhektory-i-POE-kom...
Well, or to play passively.

Answer 2

They did such a thing - they fed a garland of two hubs (Intel and D-Link).
The topology is as follows:
power supply <-> 100 meters ethernet <-> Hub <-> 100 meters <-> Hub
Power goes through two halves of pairs (brown and blue) (white-brown and white-blue +, brown and blue -)
As a 48V source, we used a transformer from an Epson LX-300 dot matrix printer (perfect fit), then a rectifier bridge and a capacitor.
At the power take-off points, a converter was installed on the LM2576HV-ADJ, according to a typical scheme:
This scheme functions without comment.

Answer 3

You can just buy this thing http://contactless.ru/store/#!/PoE-injector-for-Wi...