IAA 2015: Leoni increases safety in accidents with a pyrotechnical switch

Very fast circuit breaking in 3 milliseconds – integration in power distributors and high-current applications

Nuremberg – Leoni, the leading European provider of cables and cable systems to the automotive sector and other industries, will, for the first time at the International Motor Show (IAA) in Frankfurt (stand D08 in hall 4.1), publicly present a pyrotechnical switch that can be directly integrated in power distribution devices and pre-fuse boxes – and in fact without additional contact points and fastening components. In case of an accident, the new product will disconnect the power supply within 3 milliseconds to prevent short-circuiting.

Leoni’s new pyrotechnical solution is linked to the car’s airbag signal and responds so quickly that any deformation of the routing area and thus damage to the cable as a consequence of an impact can only occur after the current has already been switched off. This minimises the risk of a short circuit, which could then result in a vehicle fire. The innovative switch is especially well suited for use in vehicles where the battery is located in the rear and is connected to the engine compartment with a correspondingly long high power cable.

In contrast to other pyrotechnical solutions, Leoni’s switch is, with its small dimensions and low weight of only 31 grams, designed to be integrated in electromechanical components. One option, for example, would be the installation in a pre-fuse box that, on a single busbar, also contains the fast breaker mechanism alongside multiple fuses for the main circuits. The integrated pyrotechnical switch (IPS) does not require any screw connection, but is rather fitted by means of a stamping on the busbar. When triggered, the IPS cuts the connection to the specified conductor, which would normally be routed to the starter or the alternator.   

The pyrotechnical switch also boasts relatively minor power loss as well as a very high auto-ignition temperature. This is achieved with the product’s compact design as well as a low net explosive weight of the igniter.