A protective circuit for a hacker type DC converter in which a coil (L1), a diode (D1) and a capacitor (C1) are connected in series to the poles of a supply voltage source (U1). Power losses as well as rapid voltage and current variations are reduced by two suitably selected inductive elements (L2, L3) being inserted in series with the diode, and also by these inductive elements (L2, L3) and the diode (D1) being bridged over by a second diode (D2).
