| 摘要 |
A circuit for providing a leading edge type phase-cut alternating current (AC) to a load is provided. The circuit comprises a current path for coupling a load to an input AC supply, at least one primary switch arranged in said current path for implementing leading edge type phase-cutting of the input AC, the at least one primary switch arranged to operate alternatingly in one of a conductive and a non-conductive state in accordance with at least one first control signal, and a detection circuit arranged in said current path, arranged to provide a zero current detection signal for indicating the end of a half-wave in said phase-cut AC. The detection circuit comprises two parallel branches and a first MOSFET arranged in a first branch of said two parallel branches and a second MOSFET in a second branch of said two parallel branches such that the direction of the current path from the source to the drain through the first MOSFET is opposite to that of the second MOSFET, wherein one or both of the first MOSFET and the second MOSFET are arranged to receive respective second control signals for switching into one of a conductive state and a non-conductive state. |
