US: Trio show more compact smart junction box
Lear Corporation has announced a claimed "industry first" - its solid-state smart junction box technology (S3JB) which provides a "dramatic" improvement in volume, a significant reduction in weight and lower systems cost as well as improved electrical-system diagnostics and double failure-mode protection.
The S3JB, developed in a partnership between Lear, STMicroelectronics (ST) and Smart Automotive System Engineering (SASE), is being demonstrated on a Ford Escape at the Convergence 2006 Electronics Show in Detroit this week.
The primary architecture uses Lear's capabilities for smart junction boxes, connection systems, thermal management, software algorithms and electrical distribution systems and integrates ST's advanced power management solid-state drivers as the core to create the S3JB. SASE, a specialist in the application of automotive and commercial electronics, served as technology consultant.
Smart junction box technology is the main hub in a vehicle's electrical system, controlling and providing power to various electrical features. Current technology combines fuses, relays, a microcontroller and multiple (circuit board and fret) layers of interconnection into a single integrated assembly.
When Lear's advanced connection systems are combined with ST's solid-state drivers, the smart junction box is reduced from multiple-printed circuit boards to a single small-printed circuit board, reducing the number of parts, manufacturing complexity and size of the junction box.
This means a 50%-80% reduction in volume, which allows greater packaging flexibility and optimisation of the location because of the smaller size and elimination of the requirement for owner access, as well as a 40%-70% reduction in weight and a 5%-20% reduction in systems cost.
The solid-state drivers also contain proprietary technology, which results in lower processor computational load as well as more efficient use of the electrical distribution system. Using this technology, up to a 1kg saving in the weight of copper in a vehicle can be achieved.
The S3JB technology is an enabler for the integration of additional features into the smart junction box. This, combined with the benefits from the S3JB, results in a sizable cost reduction for the electrical system as well as a modest improvement in fuel efficiency.