Patent ID: 6208175
Filing Date: 2001-03-27
Classification: B60R,G01D,G01P

Abstract:
A circuit for evaluating a sensor signal from a sensor, the circuit setting a lower and an upper level for the sensor signal, the circuit comprising:a signal source that acts as the sensor, the signal source including a first current source,the first current source setting an upper current threshold and a lower current threshold,the second current source being coupled to said first current source and generating a nominal current, the nominal current falling in between the upper and lower current threshold levels, wherein a voltage across the second current source indicates a signal state of the signal source, the second current source including at least two individual current sources coupled together; andat least two amplifier circuits connected to said at least two individual current sources in said second current source, each individual current source having an associated amplifier circuit, wherein output signals in the amplifier circuits indicate whether the nominal current from the first current source from the sensor falls below the lower current threshold level or extends above the nominal current, and wherein said first and second current sources and said amplifier circuits operate together as a current limiter and an overload detector in case of a short circuit or shunt to ground.