Abstract: The switched-mode power supply contains a transformer, a switching transistor in series with the primary winding of the transformer, and a damping network on the secondary side, which has a connection for a further secondary winding via which energy is transferred from this damping network, by way of example, to a charge-storage capacitor which is coupled to this secondary winding. The connection is advantageously produced via a rectifying element, for example a diode, which is coupled after the rectifying diode (D5) for the second secondary winding. In a further exemplary embodiment, the diode in the series circuit, which is connected in parallel with the rectifier diode for the first secondary winding, is not coupled to the charge-storage capacitor for the first secondary winding, but is likewise coupled to the charge-storage capacitor for the second secondary winding.

Abstract: The switched-mode power supply according to the invention has a power factor correction circuit, which operates on the principle of a current pump and has a first coil for damping voltage spikes, as well as a second coil for power factor correction. The two inductances are in this case connected in series and are arranged on a coil former and on a common core. In one preferred exemplary embodiment, an E/E ferrite core is used as the core, and a coil former with chambers is used as the coil former, with the windings of the two inductances being arranged in different chambers. An empty chamber, which is located in the region of the air gap in the core, is advantageously arranged between the two inductances. This partially decouples the two inductances by means of the air gap, so that the damping response of the first inductance is better.

Abstract: The switched-mode power supply according to the invention has a power factor correction circuit, which operates on the principle of a current pump and has a first coil (L15) for damping voltage spikes, as well as a second coil (L19) for power factor correction. The two inductances (L15, L19) are in this case connected in series and are arranged on a coil former (SK) and on a common core (CR). In one preferred exemplary embodiment, an E/E ferrite core is used as the core (CR), and a coil former with chambers is used as the coil former (SK), with the windings (W15, W19) of the two inductances (L15, L19) being arranged in different chambers (K1, K3, K4). An empty chamber (K2), which is located in the region of the air gap (AG) in the core (CR), is advantageously arranged between the two inductances. This partially decouples the two inductances by means of the air gap, so that the damping response of the first inductance (L15) is better.

Abstract: The switched-mode power supply contains a transformer (TR), a switching transistor (T1) in series with the primary winding (WP) of the transformer (TR), and a damping network (DN) on the secondary side, which has a connection for a further secondary winding (W2) via which energy is transferred from this damping network, by way of example, to a charge-storage capacitor (C3) which is coupled to this secondary winding. The connection is advantageously produced via a rectifying element, for example a diode (D3), which is coupled after the rectifying diode (D5) for the second secondary winding (W2). In a further exemplary embodiment, the diode (D2) in the series circuit, which is connected in parallel with the rectifier diode (D1) for the first secondary winding (W1), is not coupled to the charge-storage capacitor (C1) for the first secondary winding (W1), but is likewise coupled to the charage-storage capacitor (C3) for the second secondary winding (W2).

Abstract: The switched-mode power supply comprises a transformer, a switching transistor connected in series with a primary winding of the transformer, a primary-side control circuit and a secondary-side regulating stage. The regulating stage is coupled to a coupling element for transiting a regulating signal from the secondary side to the primary side. A first switch is situated between the control input of the switching transistor and a primary-side operating voltage, and a second switch is situated between the regulating stage and a secondary-side operating voltage, with the two operating voltages being able to be disconnected using a single control signal. In this case, the isolating element transmits both the regulating information for the primary-side control circuit and the turn-off signal for the first switch. If the second switch is turned off by the control signal, the regulating stage and the optocoupler become completely currentless and consume no further power.

Abstract: A circuit for generating a dynamic focusing voltage in a television receiver utilizing overscan periods includes a focusing voltage generator. The focusing voltage is compared to a reference voltage and a switching signal is provided when the focusing voltage goes below the reference voltage. A switch is responsive to the switching signal and provides a direct focusing voltage during the overscan periods. The direct focusing voltage has a level which maintains the arithmetic mean of the focusing voltage the same during the normal scan period and the overscan periods.

Abstract: A vertical deflection circuit includes a first pin which receives a forward scanning voltage having a first level and a first frequency. During a flyback period a second pin receives a flyback voltage having a second level higher that the first level and a second frequency higher than the first frequency. A third voltage source provides a first pulse. A switch means selectively couples the first pin and the third voltage source in response to a vertical blanking signal. The vertical blanking signal is differentiated to provide a differentiated signal and a voltage divider applies the differentiated signal to the switch to apply the first pulse to the first pin.