| 摘要 |
PROBLEM TO BE SOLVED: To provide a current limiter the current limiting element of which will not be fractured, even when a large overcurrent flow to the element, and maintains a high current limiting ratio. SOLUTION: A current limiter 1 is constituted of a main circuit 2, in which a resistor R1 the electric resistance value which has a positive temperature coefficient is arranged and an auxiliary circuit 3 in which a resistor R2, the electric resistance value of which has a negative temperature coefficient is arranged in parallel with the resistor R1, and the auxiliary circuit 3 is grounded via a switch Sw. In a normal state, most of the electrical current flows to a load 4 through the main circuit 2, but when an overcurrent occurs, the electric current is inhibited from flowing to the load 4, because the ratio between the resistance values of the resistors R1 and R2 is switched so that most of the electrical current flows to the grounded auxiliary circuit 3. Therefore, the current limiter 1 can limit the overcurrent without causing its current limiting element to breakdown.
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