Abstract: To control a converter of a satellite receiving system, the converter receives not only a dc voltage but one of two different voltages (normally 13 or 17 volt) also an alternating voltage (normally 22 kHz). It has to be possible to control more equipment along the same (coax) cable like amplifiers and switchers and to switch between more sub-bands than two. To achieve this the satellite receiver includes a power supply unit having switching apparatus which can combine the supplying of one of the two dc voltages with an alternating voltage continuous tone or burst as (switching) information.

Abstract: Picture display device with one or more resonant selection pulse drivers for generating selection pulses for selecting rows of pixels. The resonant selection pulse driver has two driver output electrodes to which selection electrode(s) are connected for simultaneously generating a pulse trailing edge at one driver output electrode and generating a pulse leading edge at the other driver output electrode.

Abstract: In an oscillator arrangement (VCXO), an oscillation loop (OSL) oscillates at, approximately, the fundamental frequency of a crystal (XTL) included therein. The output signal (Sosc) of the oscillator arrangement (VCXO) is a harmonic extracted from the oscillation loop (OSL). To vary the frequency of the output signal (Sosc), a tuning circuit (VAR) is included in the oscillation loop (OSL). A stage (FIL) in the oscillator arrangement (VCXO) prevents harmonic feedback into the oscillation loop (OSL). Such an oscillator arrangement (VCXO) can be tuned over a relatively large frequency range and has a monotonous tuning characteristic.

Abstract: Known display devices include a video signal processing circuit with a black level setting circuit. This black level setting circuit measures the black level of the video signal, for example, during the field retrace interval by making use of an extra output of the video output stage. However, the measured black level has a line-frequency interference component which is caused by a parasitic capacitance in the display tube. The line-frequency interference component is fully compensated for by coupling one side of a secondary winding of a transformer, required for the focusing voltage to be generated, to a first capacitor, the other terminal of which is connected to the measuring input of the black level setting circuit, and by coupling at least a second and a third capacitor across the secondary winding of the transformer.