Patent ID: 8348355

Claim:
A circuit arrangement for switching two backup valves in a rear axle module of an electronic brake system of a utility vehicle, comprising: a first backup solenoid valve in the redundant pneumatic brake system having a first inductor in a first circuit component branch of the circuit arrangement; a second backup solenoid valve in the redundant pneumatic brake system having a second inductor in a second circuit component branch of the circuit arrangement; an extinguishing diode for the first backup solenoid valve and the second backup solenoid valve in a third circuit component branch of the circuit arrangement for a slow discharge of the first and second backup solenoid valves when the first and second backup solenoid valves are opened in a redundant operating mode in order to apply a pneumatic brake pressure when the electronic brake system fails; and a switch in a fourth circuit component branch of the circuit arrangement, by which switch pulse width modulation for controlling the magnetic fields of the first inductor and the second inductor of the first and second backup solenoid valves is applied; wherein the first and second inductors in the first and second circuit component branches of the circuit arrangement and the extinguishing diode in the third circuit component branch of the circuit arrangement are connected in parallel with one another, wherein the first and second inductors are connected to a supply voltage of the circuit arrangement at a first common circuit node via a first and a second resistor in the first and second circuit component branches of the circuit arrangement and the extinguishing diode in the third circuit component branch of the circuit arrangement, and the first and second inductors and the extinguishing diode are connected to a first terminal of the switch at a second common circuit node at an intermediate potential between the supply voltage and a ground potential of the circuit arrangement, wherein the cathode of the extinguishing diode is connected to the supply voltage, and the anode of the extinguishing diode is connected to the intermediate potential, and wherein the switch in the fourth circuit component branch is connected in series with the parallel circuit of the first, second and third circuit component branches between the intermediate potential and the ground potential, and the switch switches simultaneously the two backup solenoid valves in the redundant operating mode.