Abstract:
A protective device against excessive currents occurring in an electric circuit between a voltage source and a load mounted downstream of said device, comprising a first triggering component with high current sensitivity and adapted to be triggered, rapidly, but reversibly, in case of excessive current in the circuit, and a second triggering component, mounted in parallel with the first, capable of bearing a temporary voltage higher than the power supply voltage, when the first component is triggered, and of being triggered rapidly and reversibly thereafter. The triggering component are preferably conductive polymer components. Also, a triac switch comprising such a protective device mounted upstream of the triac and a third component is mounted on the triac trigger.