1, pure copper wire (1 square millimeter) P=18.5 Europe / kilometer (it is on some data 17.5)

2, the consideration is current on the market nominal the difference that goes up with cupreous material increases P 20% , such P=18.5*1.2=22 Europe / kilometer

3, consideration power supply makes return circuit, those who use is identical wire cable. Such distances are L(kilometer) the resistor of wire cable is R=2*P*L

4, so to supply current it is I(ampere) for camera, the voltage loss in circuit is U=I*R=2*I*P*L

5, to cut area it is S(square millimeter) the online road is medium voltage loss for cable isU=2*I*P*L/S

6, for the circuitry to many bits of power supply, can a computational electric current, after that a computational voltage loss.

Statement: This computation is confined to dc power supply, additionally this is computation of a project only, have certain error. The unit should notice in calculative process (dimension) problem