| 摘要 |
<p>This protective device includes a PTC element and a bimetal element, and is capable of providing appropriate protection even against abnormalities other than overcurrent. This protective device comprises a resin base, a first terminal, a second terminal, a PTC element, an insulation layer, a bimetal element, an arm, an upper plate and a resin cover, and is characterized in that the first terminal, the PTC element, the second terminal, the insulation layer, the bimetal element, the arm and the upper plate are stacked in this order inside of a resin housing defined by the resin base and the resin cover; the first terminal and the arm, which has a terminal function, are arranged in series to configure a primary circuit, and the first terminal, the PTC element and the second terminal are electrically connected in series to configure an auxiliary circuit. Under normal conditions, the primary circuit is in a state in which the first terminal and the arm are electrically connected in series via the contact portions of both, and meanwhile, no current flows in the auxiliary circuit; under abnormal conditions, when the auxiliary circuit is energized, the current causes the PTC element generate heat, and this heat actuates the bimetal element, interrupting the electrical connection of the first terminal and the arm, and the primary circuit becomes an open circuit.</p> |
