Circuit arrangement for supplying a control electronics system in electric machines

A circuit configuration for supplying electrical energy to control electronics for an electrical machine whose phase windings are connected to an output stage having controlled switches, comprising:

• a transformer circuit arranged between the output stage and the electrical machine, the transformer circuit being fed a phase current of the electrical machine, whereby an auxiliary voltage is produced from the phase current, the auxiliary voltage being used under specifiable conditions to supply low-side switches of the output stage;
• and
• a controllable switch element according to which a secondary side of the transformer switches on or off under specifiable conditions which include at least one missing or defective or discharged battery;
• wherein the transformer circuit includes a transformer, a primary side of the transformer is connected to a phase winding of the electrical machine.