Abstract: Regulator for a sine wave generator unit, including a load feeding power-bridge connected to an output of the sine wave generator. The regulator is inserted between a feedback output of the power-bridge and a reference voltage input of the sine wave generator. The regulator includes regulation means providing a power regulation signal (SET′) to the reference voltage input of the sine wave generator from a comparison between a signal (SENSE) at the feedback output of the power bridge and a predetermined set point signal (SETP′). The regulator (4′) is a proportional integrating differentiating regulator including start-up and/or shut-off envelope controlling means (19, 20, 21) associated to regulation means (14′, 17) for obtaining tightly controlled start-up and/or shut-off slope(s) of the signal at the load feeding output of the power bridge in addition to a tight control of the signal envelope between a start-up slope and the following shut-off slope.