Circuit arrangement for controlling the commutation in a stepping motor

In a circuit arrangement for controlling the commutation of a stepping motor, each phase winding (1) of which is connected to the detector diagonal of a bridge circuit consisting of four switching transistors (2, 3, 4, 5), a capacitor (17) is connected across each phase winding (1) and a decoupling diode (13, 14) is included in each of two arms of the bridge circuit. In case of a bridge circuit comprising complementary transistors (2, 4; 3, 5), whose emitters are connected to the terminals (6, 7) of the supply voltage (Uo) and whose collectors are interconnected in pairs, the decoupling diodes (13, 14) are included in the collector leads of the transistors (2, 4) of one type of conductivity, and protective diodes (15, 16) are connected in parallel to the collector-emitter path of the transistors (3, 5) of the other type of conductivity.