Abstract: A linear regulated D.C. power supply includes two control elements for regulating two separate unregulated D.C. voltage sources. An enabling means is used to enable the one of the two control elements which is operating at the lower instantaneous power dissipation level and to supply the regulated output of that selected control element to a load.

Abstract: A circuit for converting a triangular waveform into a sinusoidal waveform using the non-linear transfer characteristic of a first transistor differential amplifier. Second and third differential amplifiers are parallel-connected to said first differential amplifier with the slopes of their transfer characteristics in opposite sense thereto and having their operating points shifted on their transfer characteristics in opposite directions with regard to each other and symmetrically to the operation point of said first differential amplifier so that the resulting overall transfer characteristic of said first, second and third differential amplifiers has zero slope at the extremal amplitudes of said triangular waveform.

Abstract: An input circuit for electronic instruments, particularly measuring instruments, has an input for an input signal with a DC and an AC component and has an output for connection to the electronic instrument. A direct current or direct voltage source is provided, and a compensating circuit compensates the DC component of the input signal in such a way that the AC component is isolated and presented at the output. The compensating circuit is basically an impedance network consisting of three resistors connected in a .pi.-style with the two outer resistors being connected to direct voltage or direct current sources which are jointly variable in such a way that they cancel each other at the input and the DC component of the input signal can be compensated at the output.