This invention relates generally to power distribution systems for vehicles and, more particularly, to power distribution systems that are remotely configurable to selectively provide power to various circuits.
Modern vehicles, such as automobiles, employ a number of digital electronic controllers and accessories that require constant power. The power is needed to maintain settings in digital memory while the vehicle is not being used. These settings may relate to preferred positions for power mirrors and seats, diagnostic information relating to the vehicle powertrain, radio preferences, digital clocks, and a number of other applications.
When designing the electrical power distribution system for the vehicle, engineers must identify which electrical devices require constant power and which devices may have power disconnected when the vehicle is not in use. The devices that require constant power are then wired to single circuit commonly called the Ignition-Off Draw (IOD) circuit, which is protected by an IOD fuse. The IOD circuit is powered by the vehicle battery so that power is available regardless of the state of the vehicle ignition switch.
Over time, the devices on the IOD circuit can discharge the vehicle battery so that the battery is unable to provide sufficient power to start the vehicle. For example, this extensive discharge can occur when the vehicle is turned off and in transit from the manufacturing facility to a dealer, as the shipping process may take several weeks. Attempts to reduce the risk of discharge during shipping have typically involved removing the IOD fuse from the fuse box and storing it in the vehicle prior to shipping. The dealer then, as part of preparing the vehicle for sale, retrieves the IOD fuse from the storage location and reinserts it in the fuse box.
One issue with the aforementioned method of preventing battery discharge is that it is preferable to have the IOD fuse installed during manufacture, thereby facilitating comprehensive electrical testing of the vehicle during the assembly. The IOD must then be removed and stored after the electrical testing is complete and prior to shipping the vehicle. This handling of the fuse increases the likelihood of human error during manufacture of the vehicle. One possible error is that the vehicle manufacturer will forget to remove the IOD fuse prior to shipping. Another possible error is that the fuse will be mishandled during removal or storage, thereby causing damage to the fuse box. Yet another possible issue is that the fuse box will become contaminated with debris or water when the fuse box is opened to remove and store the IOD fuse.
Accordingly, an aspect of the present invention is to provide a power distribution system capable of eliminating the need to remove an IOD fuse prior to shipping the vehicle.
Another aspect of the invention is to provide a power distribution system capable of remotely and selectively powering an IOD circuit during vehicle testing at the manufacturing plant.
In accordance with these and other desired aspects of this invention, a vehicle power distribution system is provided for selectively providing battery power to a circuit. A circuit-interrupting device is arranged to respond to a control signal by selectively applying the battery power to the circuit. A circuit protection device is moveable between a first circuit position and a second circuit position, where the first circuit position is arranged to pass a current through the circuit concurrently with the circuit interrupting device. The second circuit position is arranged to pass the current around said circuit interrupting device.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.