Abstract: A drive device for operating an electrical machine has a regulator for driving a rotor winding, which has a highside switch and a de-energization switch. A first terminal of the rotor winding can be connected to a positive supply terminal via the high-side switch, the first terminal of the rotor winding can be connected to a negative supply terminal via a semiconductor component, and a second terminal of the rotor winding can be connected to the negative supply terminal via the de-energization switch. The drive device is arranged to enter a safe state in the presence of at least one fault by disconnecting and/or de-energizing the rotor winding from the positive supply terminal. At least one of the switches is designed to be redundant; and/or the regulator has a plurality of measuring points.

Abstract: An activation system for operating an electric machine includes a control circuit device for activating a rotor winding, and having a highside switch, a semiconductor component, and a de-excitation switch. A first terminal of the rotor winding is connectable to a positive supply terminal via the highside switch and to a negative supply terminal via the semiconductor component. A second terminal of the rotor winding is connectable to the negative supply terminal via the de-excitation switch. The activation system is configured to attain a secure state, when at least one fault is present, by disconnecting the rotor winding from the positive supply terminal and/or by de-exciting the rotor winding. A diagnosis may be carried out using an additional highside switch supplied with power via another activation circuit, and/or a fault detection circuit is provided, whose output signal does not change during a de-excitation.

Abstract: A drive device for operating an electrical machine has a regulator for driving a rotor winding, which has a highside switch and a de-energization switch. A first terminal of the rotor winding can be connected to a positive supply terminal via the high-side switch, the first terminal of the rotor winding can be connected to a negative supply terminal via a semiconductor component, and a second terminal of the rotor winding can be connected to the negative supply terminal via the de-energization switch. The drive device is arranged to enter a safe state in the presence of at least one fault by disconnecting and/or de-energizing the rotor winding from the positive supply terminal. At least one of the switches is designed to be redundant; and/or the regulator has a plurality of measuring points.