This invention relates to a trouble finder for testing an electrical system, especially the type which may be found in vehicles.
Most vehicles of today, such as trucks, private cars etc. have complex electric systems, for instance for the lighting of different devices. Anyone who has some time being in contact with troubleshooting in faulty electric systems has quickly realized the extent of the problem.
Typical errors which are difficult to find include short-circuiting in the wiring systems. Short-circuiting appears typically in the form of damage caused by squeezing and abrasion.
The new trouble finder is preferably to be used for tracing errors in electric systems of vehicles such as trucks and towed vehicles. A special problem of towed vehicles is that they require an external power supply for operation and control.
The use of an external power supply suggests that the towed vehicle should either be connected to a driving vehicle or that some sort of external current source must be used, e.g. batteries or transformers. Moreover, heavy trailers of trucks require great space which often makes connections of a trailer and driving vehicle impossible.
Today's workshops have solved the problem by utilizing in the first place heavy batteries usually transported on a cart or the like. It is then possible to connect the voltage required by the system by means of temporary cables. In a workshop hall, hoses and cables are usually lying on the floor which involves an awkward handling if the batteries are transported by carts. Troubleshooting with batteries also increases the risk of overheating, and consequently burns on occur cables since fuses are not used.
An alternative method of troubleshooting includes the use of transformers adapted to the required voltage level. Short-circuiting is then detected as blown fuses in the equipment. Transformers deliver alternate current and therefore cannot be used when tracing errors for instance in electric magnets, direct current motors, relays etc, which require continuous voltage. Several fuses are required in the troubleshooting as the repairer must proceed by trial and error and turn on voltage each time when a short-circuit is found not to be eliminated. Furthermore, the repairer must move in the course of the work between the equipment and the place where troubleshooting is being performed each time a fuse has blown. Finally, the repairer will not get any indication where the error is. With a trailing length that may amount to 18 m it is realized that a large part of the work is required for moving about and that the working time is prolonged.