Abstract: A telephone line circuit and system for interfacing digital exchange line circuits to a terminal interface of a switching network is disclosed. The system includes controllable active circuit impedance matching means for reducing impedance mismatch between a selected line circuit and the terminal interface. Control means controls both the active circuit impedance matching means for adjusting the effective circuit impedance to a value within a predetermined range, and the conditioning circuit gain pads for selectably adjusting the gain of a transmitted signal. Additionally, control means controls the d.c. line impedance and voltage for adjusting the effective line feed current to the subscriber loop, and provides interfaces for a plurality of line circuits to both a switching network and external processor. Supervision means provides supervision control signals to the control means and thereby permits the telephone line circuit system to provide desired telephone system functions.

Abstract: The signal generator comprises a charge transfer device providing an output signal having any desired shape so that it is particularly useful in an A/D or D/A converter. In this device charges are transferred under electrodes of which some are split in order to obtain charge portions which are then removed or transferred to the output of the device where they are added to or subtracted from previous charge portions to finally obtain a desired output signal.

Abstract: A semiconductor power element comprising two successive opposed polarity planar pn junctions, said element being positively tapered on its lateral surface in the regions of both pn junctions to form an average angle of both tapers of between 30.degree. and 60.degree..

Abstract: A bistable semiconductor component for high frequencies with a semiconductor chip includes a sequence of at least four zones of alternating opposed types of conductivity. The outer zones form the emitter zones and are more heavily doped than the two inner zones. The base zones are so doped that with a voltage V.sub.R smaller than or at most equal to the maximum inverse voltage V.sub.RS applied in the reverse direction across the two emitter zones, the shortest distance W between the two blocking layers formed at the two outer junctions is less than the diffusion length L.sub.B of the charge carriers in the base zones.

Abstract: A semiconductor power element comprising two successive opposed polarity planar pn junctions, said element being positively tapered on its lateral surface in the regions of both pn junctions to form an average angle of both tapers of between 30.degree. and 60.degree..

Abstract: A semiconductor component having at least three p-n-junctions which may be switched from a blocking state to a conducting state. The base zone, positioned between the second and third p-n-junctions, is characterized in that it comprises three single zones, the center zone of which is more highly doped and appreciably thinner than either of the two outer zones. The doping concentrations in the two outer zones are equal to one another and appreciably lower than that in a control zone, which is positioned between the first and second p-n-junctions. The effect of the foregoing construction is to reduce the recovery time of the semiconductor component without causing an increase in the forward potential drop, or vice-versa.