Actuator drive for a flap or for a valve for setting a gaseous or liquid volume flow, in particular for the heating, ventilation or air conditioning of a building, having a DC motor, having a reduction gear connected downstream, and having a gearbox-side output for the flap or for the valve, wherein the actuator drive has a motor control unit for actuating the DC motor and a voltage supply unit, wherein the DC motor is a brushless two-phase DC motor which has a stator embodied as a quadruple T armature with in each case an armature coil (C1-C4) and a radially outwardlying rotor which is mounted so as to be rotatable relative to the stator and has precisely four alternating permanent magnetic poles (N, S) which are arranged in the circumferential direction, wherein the rotor of the DC motor is connected to a spring device by means of which a restoring force is applied to the rotor in the event that the latter is deflected from a rest position, wherein the motor control unit has electrically actuatable switching means (S1, S2; Z1-Z4) as an actuating device for the DC motor in order to apply a torque having a predefinable direction of rotation, wherein the motor control unit is configured to connect the armature coils (C1-C4) to the voltage supply unit by way of the switching means (S1,S2; Z1-Z4) in accordance with the predefined direction of rotation and as a function of a rotational position of the rotor, wherein the armature coils (C1-C4) are interconnected in such a way that, when subjected to current excitation, two adjacent armature coils (C1-C4) never form magnetic poles having the same polarity, - wherein the armature coils (C1-C4) of the T armatures (T1-T4) are collectively connected in series, wherein the two ends of the series connection form a first and second bridge terminal (X, Y), and wherein the motor control unit has an H-bridge composed of four switching means (Z1-Z4) for current excitation as an actuating device, wherein the H-bridge is connected to a first and second voltage level (GND, VCC) of the voltage supply unit on the input side and to the two bridge terminals (X, Y) on the output side, or - wherein the armature coils (C1, C3; C2, C4) of two oppositely disposed T armatures (T1, T3; T2, T4) of the stator are connected in series in each case or wherein the armature coils (C1, C2; C3, C4) of two adjacent T armatures (T1, T2; T3, T4) and the two remaining armature coils (C3, C4; C1, C2) are connected in series, wherein one end of the series connections in each case forms a common motor terminal and the two remaining ends of the series connections form a first and second differential mode terminal (U, V), and wherein the motor control unit has two switching means (S1, S2) actuatable in push-pull mode as the actuating device, wherein one switching contact of the two switching means (S1, S2) in each case is connected to a first voltage level (GND, VCC) of the voltage supply unit, wherein a second voltage level (VCC, GND) is connected to the common motor terminal, and wherein the two differential mode terminals (U, V) are connected to the remaining switching contacts of the two switching means (S1, S2). - wherein the armature coils (C1-C4) of the T armatures (T1-T4) are collectively connected in series, wherein the two ends of the series connection form a first and second bridge terminal (X, Y), and wherein the motor control unit has an H-bridge composed of four switching means (Z1-Z4) for current excitation as an actuating device, wherein the H-bridge is connected to a first and second voltage level (GND, VCC) of the voltage supply unit on the input side and to the two bridge terminals (X, Y) on the output side, or - wherein the armature coils (C1, C3; C2, C4) of two oppositely disposed T armatures (T1, T3; T2, T4) of the stator are connected in series in each case or wherein the armature coils (C1, C2; C3, C4) of two adjacent T armatures (T1, T2; T3, T4) and the two remaining armature coils (C3, C4; C1, C2) are connected in series, wherein one end of the series connections in each case forms a common motor terminal and the two remaining ends of the series connections form a first and second differential mode terminal (U, V), and wherein the motor control unit has two switching means (S1, S2) actuatable in push-pull mode as the actuating device, wherein one switching contact of the two switching means (S1, S2) in each case is connected to a first voltage level (GND, VCC) of the voltage supply unit, wherein a second voltage level (VCC, GND) is connected to the common motor terminal, and wherein the two differential mode terminals (U, V) are connected to the remaining switching contacts of the two switching means (S1, S2).