Power rectifier with power supply cut-off means

A description is given of a power rectifier comprising an output (3, 5) for connection to a supply line (7A, 7B) leading to a load (Z), a cut-off device (9) being connected to said output to break the connection between said rectifier and said supply line. The cut-off device comprises a plurality of MOSFETs (11A-11B) in parallel and a control circuit (19) to make said MOSFETs nonconducting when the output current of said rectifier tends to become inverted.