Starter circuit for a motor vehicle comprising a device for stepping up the battery voltage and starter so equipped

The combination has a voltage raising device to prevent a drop in a battery voltage at a subsequent peak current produced by startup of a power circuit in an electric starter circuit (1). The voltage raising device includes an inductive type filtering device (LPF) mounted in series in the power circuit, and connected directly to a terminal (B+) of a battery of a car, where the filtering device includes a secondary winding (W2) in short-circuit, and a magnetic yoke formed by stacking sheets of ferrous material.