The cheapest on Yandex. Market UTP LAN cable with 4 pairs for laying on the street costs from 850 rubles for a 100-meter bay. I bought it and measured the diameter and resistance of cores.
Cable called Proconnect 01-0045-3-100. Sold in coils 25, 50, 100 and 305 meters, while the price per square meter is almost the same regardless of the size of the bay - 8-9 rubles per meter.
Markings on the cable.
Conductor diameter corresponds to 24AWG - 0.51 mm.
Core material - CCAW (aluminum, copper-clad).
To measure the resistance lived I used accurate multimeter Aneng AN8001 (ammo1.livejournal.com/819777.html). Wire resistance 0.1 ohms with crocodiles.
Resistance 100-meter he lived from 21.3 to 25.6 ohms.
The results of measuring the resistance (including resistance correction probe):
White and orange - 21.7
Orange - 21.3
White and green - 24.6
Green - 25.6
White and blue - 21.4
Blue - 21.6
White and brown - 24.5
Brown - 24.1
When the UTP-cable used to connect video surveillance cameras powered by the same cable (POE or passive POE), a plus power passed by the United together the blue and white and the blue wire, minus for United with brown and white and brown wire, therefore, to calculate the voltage drop across the wire is important to know the total resistance of the blue and brown pairs, each of which is connected parallel. For a 100-meter cable that resistance was 22.9 ohms (0.1 minus 23 probes).
Copper cable 24AWG standard should have a resistance of 8.42 ohms at 100 meters. The resistance of the cable is more than 2.7 times.
I bought this cable to connect the camera far from the router for 50 meters. When using passive POE (power transmitted by cable 12 volts) and consumption of 400 mA (camera consumes a current when enabled IR night lights) on 50-meter wire segment will fall approximately 3.3 Volt.
This means that the voltage power supply 13.5 V (that is how much gives BBP (ammo1.livejournal.com/1043712.html) the camera is about 10 volts, and 12 volts during feeding, it will be about 8.7 volts per cell. In both cases, the camera will work, but the intensity of illumination can vary greatly. According to the results my research (ammo1.livejournal.com/1046347.html) Backlight power when powered many chambers 10 is reduced by 50%, the supply voltage 9 volts is reduced 5 times, the supply voltage is 8.5 volts is reduced by 10 times.
I decided I would try first to connect the camera without any voltage conversion and to see if the brightness is enough. And only if it will not be enough, installed in front of the cable step-up converter, step-up voltage to 30-40 volts, and the camera step-down, reducing it to 12 volts. In any case, it is much cheaper to use expensive cables with copper conductors.
© 2019 Alex Nadozhin