Tyco releases Polyswitch circuit protector line

The AHEF series provides resettable overcurrent protection for bus and truck wire harnesses utilising 24V electrical systems.

The seven devices in the range have hold-current ratings from 0.50A to 10A with a maximum fault-current rating of 100A.

The maximum operating voltage rating for the devices is 32V, the same as for vehicle electronics in Europe, while the maximum operating temperature is 125C, making them suitable for passenger and engine compartments.

This is the first Tyco Electronics range to offer 32V with a high temperature rating.

All the devices are housed in radial-leaded packages.

Next generation wire harnesses generally have a hierarchal structure, with the main power trunks dividing into smaller branches with overcurrent protection at each node.

This structure results in the use of smaller wires, which save volume, weight and cost, as well as maximum system protection and fault isolation.

Jasmine Hu, product manager for Raychem Circuit Protection Products at Tyco, said: 'It is difficult to route all the wires in and out of a single junction box that is accessible by the driver.

'By using resettable circuit protection devices, such as the AHEF family, multiple junction boxes can be used that don't need to be driver accessible.

'For example, they can be placed under the seat or in door panels and because the devices are rated to 125C, the junction boxes can be located close to their intended electronics whether in the passenger compartment, protecting body control units, or in the engine compartment protecting HVAC controls.' The resettable devices are of through-hole construction.

They can be directly installed onto PCBs with pick and place equipment.

The devices are tested to the AECQ200 standard and are ROHS and ELV compliant.