| 摘要 |
<p>The current is fed via the coil of the surge limiting inductance. The magnetic circuit, or yoke, of the choke consists of a closing piece, side arms and a cross arm. Permanent magnets are introduced into a gap in the middle of the cross arm. The effect of these permanent magnets is to induct a saturated flux in the yoke. This permanent flux is in opposition to any flux caused by current surges through the coil. If the current through the coil exceeds a predetermined level, the core is brought out of saturation and develops a back e.m.f. which opposes the surge.</p> |
