The wire is an electrical resistance, which put up resistance against the current. This resistance is a material constant, which is determined at 20°C. This material constant is call specific electrical resistance. Though this characteristic, the wire get the temperature off 300°C. The increase of the temperature is physical explain by the put up residence against. The wire is a neutral conductor till a current flow. If you impressed a voltage it arise an electrical field and the electrons start to accelerate. These are not components of the metal grind. And they move in the direction of the positive pole. The metal grind begins to swing as a result of the flux, this make the move of the electrons more difficult, so they collide with the particles in the swinging metal grind. By that a friction arises. The result oft this is, that energy will be free in form of heat.
The dependence of the resistance in form of a wire to the length and his area respectively his diameter one can describe like follow:
The area is
The resistance is described as the relation between voltage and amperage.
The maximum value of the voltage is 40V and so you have the follow value of the wires.
Picture III.12: Parameters of the wires
So the amperage is defined about in the time t moved current quantity and the voltage U as the moved particles Q. You imagine a pipe, so more volume flow though as though a little. The voltage is a way time law. If the flow will be go with a constant speed, so the particles need more time if the pipe also the way is longer. If the pipe is longer so the resistance from the pipe against the matter is bigger, because the particles rub longer on the pipe wall. The resistance will be reducing if the diameter is bigger.
The follow diagram shows that:
Picture III.13: The resistance dependence on the diameter
Picture III.14: The resistance dependence on the length
The Foam Cutting System GmbH produces machines with more then one wire. These difficult wires are parallel switched, that is why the maximum voltage of 40V is not exceeded.
The parallel switch has an effect like the area is enlarging. That's means that the voltage will be constant and the amperage will be increase raise.
So it is:
That means that the whole resistance is:
So 5 wires with a diameter of 0.1 mm are correspond to 1 wire with a diameter of 0.35mm.