The invention proposes a driver circuit (1, 20) for illuminants, particularly LEDs, having: —a circuit (2), such as an inverter in the form of a half-bridge circuit that has a resonant circuit (3), that is clocked by means of at least one switch (FET1, FET2), —a transformer (L2) that follows the resonant circuit (3) and from whose secondary winding (L2b) the illuminants can be supplied with power, and —a control circuit (ST) that clocks the switches (FET1, FET2) of the clocked circuit (2), wherein an actual signal (ILED_PRIM) that indirectly reproduces the current through the illuminants and that is inductively output on the secondary side (L2/2) of the transformer (L2) is fed back to the control circuit (ST), wherein the control circuit (ST) is designed: —to regulate the current through the illuminants by clocking at least one switch (FET1, FET2) of the clocked circuit (2) on the basis of the actual signal (ILED_PRIM), and/or —to use the actual signal (ILED_PRIM) to record a fault state following the secondary winding (L2b) of the transformer (L2) and/or the illuminants and to take this as a basis for outputting a fault signal and/or for altering the actuation of the clocked circuit (2).