Abstract: A programmable transducer device that includes a signal source (e.g., a sensor) and a transducer output to output a transducer output signal and to receive a control signal from an external control unit. The control signal is superposed on the transducer output signal, and is detected at the transducer output from a resultant superposition signal by a detector circuit. The transducer output signal and the control signal may co-exist on the transducer output. Advantageously, providing a programmable transducer device that is actuated by control signals conducted through the transducer output and does not need to be switched over to a special receiving state, ensures the uninterrupted transmission of transducer output signals even while the control signals are received by the programmable transducer device. In addition, no additional signal path is required for programming.

Abstract: A circuit member has an inner switching arrangement having an operating voltage line and a ground connecting line connecting on a switching circuit a ground contact to the inner switching arrangement. A reverse polarity protective device has a protective transistor arranged in the ground connecting line. During normal operation, defined by having an operating voltage applied to the operating voltage line and by having a ground potential applied to the ground connecting line, the protective transistor is in a conducting state. In a reverse polarity situation, defined by having the operating voltage applied to the ground connecting line and by having the ground potential applied to the operating voltage line, the protective transistor is in a non-conducting state. The protective transistor is configured to carry a high operational voltage in the reverse polarity situation.