| 摘要 |
PROBLEM TO BE SOLVED: To provide a small fuse of large breaking capacity. SOLUTION: A fuse 30 is mounted on a circuit board so that a pair of metal terminals 35 are electrically continuous to the circuit. A current flows a metal wire 36 to generate Joule heat. When an excessive current flows in the circuit, the Joule heat generated at the metal wire 36 raise the temperature of it, which reaches the melting point to melts the metal wire 36. An arc occurs between the ends on the hollow part 31 sides of the pair of metal terminals 35. The arc discharge heats the air in the hollow part 31 while a heat absorbing plate 37 absorbs the heat generated by the arc discharge. The increase of internal pressure of a case 32 is suppressed to prevent it from broken by the arc discharge. Re-occurrence of the arc discharge is prevented to surely cut off the excessive current. The breaking capacity of the fuse 30 rises, so even the circuit of AC with power factor added is allowed to cut off.
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