CURRENT FUSE DEVICE INDEPENDENT OF AMBIENT TEMPERATURE

PURPOSE:To enable a breaking operation always at a constant operating current independent of change in an ambient temperature by compensating a decreased amount of the fusing current of a current fuse main body due to temperature rising-up with a current flowing through a conductor having a negative temperature coefficient of a electric resistance. CONSTITUTION:To a current fuse main body 11, a series circuit comprising an NTC thermister 14 as a conductor having a negative temperature coefficient of an electric resistance and an auxiliary fuse 15 fused after fusing of the main body 11 is connected in parallel. When rising-up of an ambient temperature reduces the electric resistance of the NTC thermister 14, a current flowing through the thermister 14 and the fuse 15 increases while a current flowing through the main body 11 decreases. Accordingly, a decreased amount of the fusing current of the main body 11 due to the temperature rising-up is compensated with a divided current into the thermister 14 and the fuse 15. Therefore, an operating current for fusing the main body 11 can be kept constant irrespective of the ambient temperature.