| 摘要 |
<p>The sensor (10) comprises a cylinder (12) divided into two cylinder members (13,14) with a common magnetic head (15) interposed between them. One of the members (13) contains a viscous fluid sealed inside and an oil plunger (16) and the other member (14) contains an operating plunger (19) projecting partly out of the cylinder. The plungers are biased by respective springs (17,30) normally away from the magnetic head (15). When a short-circuit current is detected by a coil (24) wound on the cylinder (12), the operating plunger (19) is immediately attracted by the magnetic head (15) independently of the oil plunger (16) prior to its attraction to the magnetic head. When a relatively small overcurrent is detected by the coil (24) the operating plunger (19) is not attracted to the head (15) until the oil plunger (16) reaches the head, thus achieving a time delay.</p> |
