Circuit layout and process for generating a supply DC voltage

Process for generating an output voltage (U.sub.out) at an output of a signal generator unit (Sat) that, via said output, transmits signals to an evaluation circuit (I.sub.test) by current pulses (I.sub.signal) superimposed onto the output voltage (U.sub.out), and where the output voltage (U.sub.out) is derived from a non-constant input DC voltage (U.sub.batt) and provided to the output of the signal generator unit (Sat), preferably with a constant net value (U.sub.nom), said process comprising:

• connecting the output of the signal generator (Sat) to a non-constant input DC voltage source via a voltage regulator;
• generating a DC voltage (U.sub.Z) in a dependent relationship to the input DC voltage (U.sub.batt) in preferably three interrelated input voltage intervals (I.sub.1, I.sub.2, I.sub.3) such that
• i1) the input DC voltage (U.sub.batt) is provided in a first voltage interval (I.sub.1), reduced by a constant first value (.DELTA.U.sub.1),
• i2) in a following second voltage interval (I.sub.2), the DC voltage (U.sub.Z) is provided as a constant nominal value (U.sub.nom), and
• i3) if the input voltage (U.sub.batt) exceeds this second voltage interval (I.sub.2), the DC voltage (U.sub.Z), reduced by a second constant value (.DELTA.U.sub.2), tracks the input voltage, and
• controlling the output voltage U.sub.out at the output to the signal generator unit (Sat) via the regulator so as to track the generated DC voltage (U.sub.Z).

Process for generating an output voltage (U.sub.out) for a signal generator unit (Sat) where the output voltage (U.sub.out) is derived from a non-constant input DC voltage (U.sub.batt) and provided to the signal generator unit (Sat), preferably with a constant net value (U.sub.nenn),

• and with the signal generator unit (Sat) transmitting signals to an evaluation circuit (I.sub.mess) by current pulses (I.sub.signal) superimposed onto the output voltage (U.sub.out), said process comprising:
• generating a DC voltage (U.sub.Z) in a dependent relationship to the input DC voltage (U.sub.batt) in preferably three interrelated input voltage intervals (I.sub.a, I.sub.2, I.sub.3) such that
• i1) the input DC voltage (U.sub.batt) is provided in a first voltage interval (I.sub.1), reduced by a constant first value (.DELTA.U.sub.1),
• i2) in a following second voltage interval (I.sub.2), the DC voltage (U.sub.Z) is provided as a constant nominal value (U.sub.nom), and
• i3) if the input voltage (U.sub.batt) exceeds this second voltage interval (I.sub.2), the DC voltage (U.sub.Z), reduced by a second constant value (.DELTA.U.sub.2), tracks the input voltage;
• controlling the output voltage U.sub.out at the output of the signal generator unit (Sat) to track the generated DC voltage (U.sub.Z);
• and
• wherein said step of generating the DC voltage (U.sub.Z) includes connecting a circuit arrangement to the non-constant voltage source (U.sub.batt) to provide the D.C. voltage (U.sub.Z) at its output, with the circuit arrangement comprising:
• a first current path, having a number (n) of serially connected diodes (D.sub.1 . . . D.sub.n) whose connections are in a pass direction, connected at one end to the input DC voltage (U.sub.batt) and at its other end to ground via a first resistor (R.sub.1) and to the output for the DC voltage (U.sub.Z) via a second high impedance resistor (R.sub.2);
• a second current path, connected in parallel to the first current path, and comprising a first Zener diode arrangement (Z.sub.1) connecting the input DC voltage (U.sub.batt) to the output for the DC voltage (V.sub.2), and, a third resistor (R.sub.3), in a series connection with a second Zener diode arrangement (Z.sub.2), connecting the output for the DC voltage (U.sub.Z) to ground.

Process for generating an output voltage (U.sub.out) at a port of a signal generator unit (Sat), where the output voltage is derived from a non-constant DC input voltage source (U.sub.Batt) and provided to the signal generator unit (Sat), preferably with a constant net value, that transmits signals to an evaluation circuit via the same port by current pulses (I.sub.Signal), and

• said process compromising:
• generating a reference DC voltage (U.sub.Z) in a dependent relationship to the input DC voltage (U.sub.Batt) in three preferably interrelated input voltage intervals (I.sub.1, I.sub.2, I.sub.3) such that
• i1) in a first voltage interval (I.sub.1) the reference voltage (U.sub.Z) is (equal) the input DC voltage (U.sub.Batt) reduced by a constant first value,
• i2) in a following second voltage interval (I.sub.2), the reference voltage is provided at a constant nominal value, and
• i3) in the third voltage interval, when the input voltage (U.sub.Batt) exceeds this second voltage interval (I.sub.2), the reference voltage tracks the input voltage reduced by a second constant value,
• and
• providing the output voltage (U.sub.out) to the port of the signal generator unit (Sat) via a control circuit, which is responsive to the reference voltage (U.sub.2, which is connected between the port and the DC input voltage source (U.sub.Batt), and which regulates the output voltage (U.sub.out) at the port so as to track the generated reference voltage (U.sub.Z) independently from the current pulses (I.sub.signal).