Patent ID: 6175480
Filing Date: 2001-01-16
Classification: H01C,H01H,H02H,H05K

Abstract:
A thermal trip arrangement including a varistor mounted to a printed circuit board characterised in that the varistor comprises a voltage dependent resistor disc sandwiched between a pair of metallic electrically conducting discs and in that the printed circuit board provides mounting means for the varistor comprising an aperture through the printed circuit board for slidingly receiving the varistor with the central axis of its discs generally parallel to the plain of the circuit board, conducting tracks of the circuit board leading to each side of the aperture adjacent the conducting disc of the varistor mounted therein and heat sensitive fixing means providing electrical contact between said discs and tracks, the heat sensitive fixing means being adapted to hold the varistor in the aperture and release the varistor therefrom when the fixing means reach a predetermined temperature, the mounting means including also biasing means for urging the varistor out of the aperture.