| 摘要 |
<p>A circuit protection device for protecting an electrical circuit from a voltage transient comprises a semiconductor threshold switching element (52, 54, 55) connected or arranged to be connected between a current carrying line and earth, and a capacitor (51), preferably having a capacitance of 0.1 to 2 microfarads connected in series with the switching element between the switching element and earth. In a preferred form of the invention, a number of threshold switching elements that are each connected to a common capacitor located between the switching element and earth. The device enables semiconductor threshold switching materials to be used for circuit protection without the low frequency compounds of the pulse or direct currents in the lines from latching the switching material in its low resistance state.</p> |
