Abstract: The invention relates to a data communication system, an electronic module with a receiver device, and an electronic module with a transmitter device having two outputs which are used to transmit a differential or symmetrical signal from the transmitter device. The invention is characterized in that the electronic module is also provided with a converter which is used to convert the differential or symmetrical signal into an asymmetrical signal.

Abstract: A step-down converter includes a self-conducting switching transistor (T1) and an inductance (L) located in a series arm, and a freewheeling diode (DF) located in a shunt arm. The switching transistor (T1) is controlled by a control transistor (T2). The control transistor supplies a blocking voltage, which is generated by a Zener diode (D1) in the series arm, to the switching transistor (T1) once a maximum value for a current (IL) in the series arm has been reached.

Abstract: A step-down converter includes a self-conducting switching transistor (T1) and an inductance (L) located in a series arm, and a freewheeling diode (DF) located in a shunt arm. The switching transistor (T1) is controlled by a control transistor (T2), The control transistor supplies a blocking voltage, which is generated by a Zener diode (D1) in the series arm, to the switching transistor (T1) once a maximum value for a current (IL) in the series arm has been reached.

Abstract: In a method and configuration for forming a line termination at two line terminals of a telephone line, alternating signals are separated from direct signals applied to line terminals, referred to a reference variable and added to a transmission signal from a transmission terminal to form a resultant actual-value signal. The resultant actual-value signal is compared with a reference signal at a gain-controlled amplifier. The reference signal is formed with an impedance transmission function corresponding to a given termination impedance by weighting the alternating signal at one of the line terminals being connected to a current sensor resistor. A current between the line terminals is determined with a control transistor associated with the current sensor resistor. The control transistor is controlled with the gain-controlled amplifier.