| 摘要 |
<p>A manually-operated direct current cutoff switch (1) in which a nonlinear resistor PTC (9), via a connecting section (3-1), a top electrode (9-1), a bottom electrode (9-2), a connecting line (6a), and a movable section (6), is parallel connected to a contact circuit composed of a first fixed contact (5-1) and a first movable contact (4-1). At first, when the first fixed contact (5-1) and the first movable contact (4-1) are opened, the contact circuit is a closed one because of the parallel connection of PTC (9), thereby impossibly producing a surge voltage. The cutoff current flows through the PTC (9) and the drop in the resistance value due to the instant heating of the PTC (9) allows the passage of the peak current. Then the rise in the resistance value of PTC (9) causes the restore of the power supply voltage. After that, the second fixed contact (5-2) and the second movable contact (4-2) are opened, completely cutting off the current.</p> |
