Patent ID: 7245474

Claim:
A circuit arrangement to control a bistable magnetic valve in which a magnetic coil is to be supplied with an electrical current pulse to switch the magnetic valve from a first stable valve state, in which a magnetic armature of the magnetic valve is in a first end position, into a second stable valve state, in which the magnetic armature of the magnetic valve is in a second end position, comprising a power supply source to provide a supply voltage, a power supply device fed by the power supply source and able to be activated during the current pulse by an entered control signal to create a coil current flowing through the magnetic coil, wherein the coil current being set to a setpoint, and changeover circuitry operable to reduce the setpoint of the coil current during the current pulse before the magnetic armature reaches the second end position and operable to reduce the setpoint of the coil current to a lower setpoint when the second end position has been reached; wherein said changeover circuitry includes a differential amplifier producing a output signal indicative of the coil current, wherein said differential amplifier output signal is provided to a first terminal of a comparator and wherein said first terminal of said comparator is switchably connected to a voltage divider circuit.