Belimo IP Department

An apparatus (102), an actuator device (103) incorporating the apparatus (102), and a corresponding method of controlling a motor (106) are described. The apparatus (102) comprises a rectifier (124), a low-pass filter, LPF, (126), and a circuit (120) for limiting inrush current. The circuit (120) passes a half-wave output (214, 306) from the rectifier (124) through one of a plurality of resistance paths based on the current of the half-wave output. In one embodiment, the rectifier (124) has first and second input interfaces for separate input signals (204, 206). In another embodiment, the rectifier (124) has a single input interface and is configured to convert positive and negative voltage levels of an input signal into first and second half-wave outputs which are passed through respective sets of resistance paths. A charge pump (402) may be included.