Waytek has introduced PolySwitch circuit protection devices as a resettable over-current protection solution in vehicle, heavy truck and equipment wire harnesses.

Waytek's new PolySwitch circuit protection devices provide resettable over-current protection in a 2.8mm footprint and solid state design. They are an easy drop-in replacement for mini fuses and type II circuit breakers in 12V vehicle systems.
Unlike Type II bimetal circuit breakers, which typically cycle several times before latching, the PolySwitch BD280 devices features a solid state design with no moving parts or contacts to arc, erode or weld together. The PolySwitches operate with a resistance switching action that latches immediately following an overcurrent tripping condition. Such latching occurs at a lower battery voltage and lower environmental temperature than circuit breakers and fuses.
The PolySwitch devices provide virtually constant power consumption across a voltage range of 4V to 14V. They have less thermal cross talk between devices than Type II bimetal circuit breakers due to their low power dissipation and flatter thermal derating. Rated for temperatures between -40ºF and +257ºF, the PolySwitch BD280 devices pass more current at higher temperatures than bimetal circuit breakers and are suitable for harsh underhood applications.
Bright color-coded housings and rated current values printed on the top of the devices make replacement of automotive fuses and bimetal breakers easy, and help prevent installation errors. PolySwitches also have exposed probe points to facilitate inspection and faultfinding, helping lower labor time and costs.