Compressor for generating compressed air, compressed air supply system, pneumatic system, and method for operating a compressor

A compressed air supply system for a vehicle, the compressed air supply system comprising:

• a compressed air supply line having a compressor system, the compressor system including:
• a brushed direct current electric motor (BDC electric motor);
• a compressor configured to be driven by the BDC electric motor;
• a motor control circuit configured to delimit an operating current of the BDC electric motor to a time-varying current threshold value, the motor control circuit including:
• a free-running current path, the free-running current path being connected in parallel to the electric motor, the free-running current path including a free-wheeling diode and a MOSFET power transistor having an integrated free-wheeling diode, and
• a switch controller, the switch controller being configured to specify, in a time-varying manner, a switched-on time period (t_ON) and a switched-off time period (t_OFF) for the electric motor, wherein the switched-off time period is determined as a function of the time-varying current threshold value so as to limit an amount of energy dissipated in the free-running current path to a dissipated energy threshold value;
• a compressed air connection;
• a ventilation connection to the environment;
• a first pneumatic connection between the compressed air supply line and the compressed air connection, the first pneumatic connection including an air dryer and a separating valve;
• and
• a second pneumatic connection between the compressed air connection and the ventilation connection.

A method for operating a brushed direct current electric motor (BDC electric motor) in a compressor system for generating compressed air for a compressed air supply system of a vehicle, the method comprising:

• driving a compressor of the compressor with the BDC electric motor;
• controlling, by a motor control circuit, the BDC electric motor so as to delimit an operating current of the BDC electric motor to a time-varying current threshold value, wherein the motor control circuit includes a free-running current path connected in parallel to the electric motor, the free-running current path including a free-wheeling diode and a MOSFET power transistor having an integrated free-wheeling diode, and
• specifying, by a switch controller in a time-varying manner, a switched-on time period (t_ON) and a switched-off time period (t_OFF) for the electric motor,
• wherein the switched-off time period (t_OFF) is determined as a function of the time-varying current threshold value so as to limit an amount of energy dissipated in the free-running current path to a dissipated energy threshold value.