| 主权项 |
1. A circuit interruption device comprising:
a main branch; a secondary branch having an electrical on-resistance which is higher than an electrical on-resistance of the main branch; and first and second terminals for connection, in use, to an electrical network, the main and secondary branches extending between the first and second terminals; wherein the main branch includes a switching apparatus which is switchable to selectively allow current to flow in the main branch in a normal mode of operation or commutate current from the main branch to the secondary branch in a fault mode of operation, and the secondary branch includes at least one switching device, the or each switching device including at least one normally-on switching element, the secondary branch further including a control unit in communication with the or each normally-on switching element, the secondary branch further including a power extraction circuit which is electrically coupled with the control unit, wherein during the normal mode of operation the or each normally-on switching element is in an on-state to permit the secondary branch to conduct current, and during the fault mode of operation the control unit controls the switching of the or each normally-on switching element to an off-state to inhibit current flow in the secondary branch, wherein the power extraction circuit extracts power from current flowing in the secondary branch to drive the control unit. |
