| 摘要 |
A circuit protection arrangement (16) which, when series connected in a line (14) of an electrical circuit, will allow normal currents to pass under normal operating conditions and will switch to produce an open state in the line (14) when subjected to an overcurrent, and which comprises: a) a current sensing circuit (30), which, in use, senses a current level on the line; b) a first field effect transistor (FET) (22) which comprises a source, a drain and a gate, and which, in use, has its source and drain connected in series in the line (14); c) a second FET (26), which comprises a source, a drain and a gate, and which, in use, has its source and drain connected in series in the line (14); and d) a control circuit (34) which is coupled to the current sensing circuit and to the gates of the first and second FETs (22, 26), and which, in use, switches the first and second FETs (22, 26) OFF when the current level sensed by the current sensing circuit (30) is above a predetermined current level, thereby producing an open state in the line (14). The arrangement (16) provides resettable overcurrent and overvoltage protection in electrical circuits, and is particularly useful in cable television (CATV) circuits.
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