General information about on-board electrical equipment (Mondeo 1)

When checking electrical equipment in technical documentation, the car owner encounters the concepts of "voltage, current and resistance". Voltage is measured in volts (V), current in amperes (A) and resistance in ohms (R). In a car, the concept of voltage usually means the voltage of the battery. In this case, we are talking about a direct current voltage of approximately 12 V. The value of the battery voltage, depending on the degree of its discharge and the outside air temperature, can be 10-13 V. On the other hand, the voltage generated by the generator for the on-board network at an average engine shaft speed is approximately 14 V.

The term "current" is relatively rare in the field of automotive electrical supply. Current is indicated, for example, on the back of fuses and indicates the maximum current that can flow without blowing the fuse and therefore without breaking the electrical circuit.

Wherever current flows, it must be shunted by a resistance. The resistance depends, among other things, on the following factors: the cross-section and material of the wire, the current consumption, etc. If the resistance is too high, then functional disturbances occur. For example, the resistance of high-voltage wires should not be too high, otherwise the strength of the spark plugs, which ignite the fuel-air mixture and thus start the engine, is reduced sufficiently.