Mechanism of unstable behavior of parallel fuses as an openingswitch

Fuses, when used as an opening switch, are often connected in parallel to handle large energies. Here, an experiment using two fuses is carried out to understand the behavior of parallel fuses clearly. The waveforms of current flowing through each fuse are different. Unstable behaviors, in which the difference of the currents flowing into the two fuses increases, are observed, and the condition and probability of appearance of the unstable behavior are discussed. The cause of the unstable behavior is that the rate of change of fuse-resistivity with input energy is different depending on the state of the wire. Any differences in initial dimensions of the parallel fuses or any kind of disturbance during the fuse action could immediately trigger off the unstable behavior