Abstract: A frequency divider circuit realized by means of two piled bistable transistor pairs, the signal, whose frequency is to be divided, being applied in phase to the emitters of the lower transistor pair and in phase opposition to the auxiliary emitters of the upper transistor pair.

Abstract: A small lightweight power-supply device a d.c. motor powered either by the a.c. supply voltage or by an accumulator battery which dissipates little power and has a well-defined output characteristic for a wide range of input voltages.The device comprises a flyback converter, the forward sweep time being a function of the output voltage and the current through the primary winding of the transformer of the flyback converter. The forward sweep time is controlled by a control circuit which is integrated for the greater part. There is provided a starting circuit. A level detector in the control circuit ensures that this circuit is activated only when its supply voltage, which is applied via the secondary winding of the transformer, is sufficiently high.