| 摘要 |
<p>An arrangement for protecting an electrical circuit from a voltage transient comprises a threshold foldback device (6) arranged to be connected between a pair of current carrying lines of the circuit, and additional overvoltage protection device (9), connected in parallel with the threshold foldback device, and a capacitor (7) having a capacitance in the range of 10 pF to 200 nF connected in series with the threshold foldback device but not with the additional overvoltage device. The additional overvoltage protection device switches more slowly than the threshold foldback device and preferably is a device such as a spark gap or gas discharge tube that exhibits foldback or crowbar characteristics. The arrangement can be employed to protect an electrical circuit or component from a voltage transient and will usually have a low capacitance which enables it to be used in very high frequency systems.</p> |
