An electronic circuit is for the gradual start-up of electric loads, particularly halogen lamps. The circuit may include a power device having an output terminal connected to the electric load and having at least one control terminal receiving a predetermined driving current value. The circuit may further include a comparator having a first input terminal coupled to the power device output and a second input terminal kept at a reference potential. The comparator output may be connected to a controlled switch inserted upstream of the control terminal to control the opening of the switch and adjust the start-up phase of the power device according to the value of the reference potential.