| 摘要 |
<p>A plastic coil bobbin has a recess with the precise dimensions of a thermal fuse. On one side, the recess is open so that, as the coil is wound on the bobbin, successive layers of coil wire form a wall-like surface closing that open side. As the fuse is press fit into the recess, it is also forced into intimate contact against the wall of wire. Thus, the only material between the fuse and wire is a thin plastic shell forming the fuse housing. Since the fuse rating takes this wall thickness into account, there is effectively no thermal insulation between the coils and the fuse. Accordingly, under overheating conditions, the fuse opens a circuit when there is overheating and before a fire can start.</p> |
