摘要 |
A filtering and protection circuit (10), for use in a power distribution system including live, neutral and ground conductors (L, N, G) and having a circuit-breaking device (12) in one of the conductors, includes transient protection devices (16) connected from a common circuit point (18) to the respective conductors (L, N, G) of the system. Failure (shorting) of any one of these transient protection devices can bring about actuation of the circuit-breaking device (12). The protection devices may comprise silicon diode transient voltage suppressors suitable for high voltage applications, clamping at a rated voltage in one direction and having a forward diode characteristic in the other direction. Each such suppressor may be paired with a parallel capacitor (22) protected by its diode from surges or transient voltages. Such pairing of suppressors and parallel capacitors can enable polarized capacitors to be used in AC circuitry. |