Repeatable Fuse for Preventing Over-Current

A reusable comprising:

• a housing;
• a first lead terminal disposed at an inner side of the housing;
• a second lead terminal disposed at another inner side of the housing;
• a spindle disposed in the housing to be electrically disconnected from or connected to the first lead terminal and electrically connected to the second lead terminal;
• a main spring disposed between the first lead terminal and the spindle, and configured to electrically disconnect the first lead terminal and the spindle from each other;
• a bias spring disposed between the spindle and the second lead terminal, and configured to electrically disconnect the first lead terminal and the spindle from each other or electrically connect the first lead terminal and the spindle to each other;
• and
• a positive temperature coefficient thermistor inserted into an inner side of the housing, and connected to either the first lead terminal and the housing or the first lead terminal and the main spring,
• wherein the positive temperature coefficient thermistor comprises a positive temperature coefficient element, an electric resistance of which increases when a temperature of the positive temperature coefficient element is higher than a specific critical temperature,
• when an over-current that is greater than a reference level is supplied to the positive temperature coefficient thermistor and the temperature of the positive temperature coefficient thermistor is thus higher than the specific critical temperature, then the electric resistance of the positive temperature coefficient thermistor increases, the main spring is extended, and the spindle is moved toward the other inner side of the housing due to a tensile strength of the main spring and is thus electrically disconnected from the first lead terminal, thereby continuously blocking flow of current between the second lead terminal and the first lead terminal, and
• when the over-current subsides, then the positive temperature coefficient thermistor is cooled, the tensile strength of the main spring decreases, and the spindle is moved toward the inner side of the housing, is electrically connected to the first lead terminal, and thus returns to the original position.