Abstract:
A television receiver providing a stable image whether or not a composite color signal is present, in which a transmitter-recognition processes the television synchronization signals of the composite color signal. A character generator displays alphanumeric as well as graphic characters. The deflection generators and the character generator are operative with TV signals as well as characters that are alphanumeric as well as graphic. The deflection generators and the character generator are driven by control signals. An oscillator controls the deflection generators, and a phase comparator operates in the presence of synchronization signals to synchronize the oscillator. The phase comparator receives no signals from the input terminal when no synchronization signals are present, so that the oscillator oscillates at a fixed preadjustable frequency to provide a stable image.
Abstract:
An arrangement for automatic switching of the regulating speed of a phase regulating circuit, in which the regulating speed is not switched abruptly. The regulating speed is, instead, switched either discontinuously or continuously, so that it does not attain a high level before the midpoint of the synchronizing pulse. The regulating speed is increased within a synchronizing window to an increasing extent up to the midpoint of the window, whereas the regulating speed decreases to a decreasing extent from that midpoint. The regulating speed of the phase regulating circuit is associated with the horizontal deflection in a television receiver, where interference in the vicinity of the synchronizing pulse has a detrimental effect, particularly near the edges.
Abstract:
An arrangement for compensating against the magnetic field of the earth in a picture tube in remote-controlled video-display equipment, in which a compensating voltage is generated by a remote-control channel in the video-display equipment. This voltage is applied to a compensation coil in the picture tube. Current through the coil is adjusted in finely-divided incremental steps, and the current is continuously adjustable. The compensation voltage is applied to one end of the compensation coil, whereas the other end of the coil is supplied with substantially half of the operating voltage of the display equipment.
Abstract:
1. Circuitry for automatically switching the control speed of a phase-control circuit.2.1. The switching is, especially in conjunction with different signal sources employed with a television receiver, either difficult or possible only by reserving prescribed program locations. The advantage of the invention is that it becomes possible to switch over without great expenditure to the higher control speed only while necessary and back to the low speed when it no longer needs to be high.2.2. The invention is characterized in that a control circuit 12 increases the control speed, independent of whatever signal source is being employed to produce the picture, only during vertical flyback.2.3. The circuit can be employed in television receivers to reproduce both broadcast television signals and video signals from a recorder connected to the receiver.
Abstract:
A television set with videotext and/or teletext decoders having character generators which are synchronized by the deflection generators of the television set and in which audio will be forwarded only when an authorized television signal is being received and in that a memory in the decoder will be accessible to display a recognizable image even when the television transmitter is turned off.
Abstract:
A device enables to reproduce without flicker mixed signals from VT and/or BTX decoders during the reproduction of television signals (mixed operation). This is obtained by a video frequency scanning field compensation in the vertical direction effected by a video frequency additional connectable scanning amplifier which supplies a reduced inductivity additional scanning winding.
Abstract:
A process for synchronizing horizontal deflection of electron beams in television recievers having a reproduced picture with a visible component, when no transmission signals from a television transmitter are present. If an emitted signal is not available, the synchronization is suspended during the time of the visible picture trace, and is activated only during the picture blanking time. For this purpose, the procedure is to switch off a circuit that synchronizes horizontal deflection during the visible component of the reproduced picture. A synchronization circuit is activated only while the picture is being blanked.
Abstract:
A primary winding of a transformer is coupled to a source of input voltage and to a controllable switch. The switch is responsive to a first control signal for generating output pulses in the transformer secondary windings. A supply circuit is responsive to the output pusles and generates a first supply voltage. A capacitor charging circuit includes a thyristor that is coupled to one of the transformer secondary windings. The thyristor receives the output pulses for providing charging pulses to the capacitor for generating a second supply voltage. A control circuit is coupled to the thyristor for varying the number of output pulses occurring relative to a given number of charging pulses to regulate the second supply voltage.
Abstract:
A television receiver in which a microcomputer controls an operating part, and a clock generator for the microcomputer is synchronized by synchronization pulses in the television signal transmitted to the receiver. The clock generator is also in the form of a control generator for a switching network part and for the deflection stages of the television receiver. The signal from the clock generator is divided and processed by a pulse-width modulator. This pulse-width modulator emits a control signal for controlling the switching network part.
Abstract:
Circuitry for limiting a rectified operating voltage.To recover energy from unutilized power from the secondary winding of a switching-network transformer, it is recirculated to the primary winding through a diode. When appliances fail, the excess energy component can increase to the extent that components are destroyed because the operating voltage increases.To prevent this situation the excess energy is recirculated into a higher operating voltage U.sub.S through a diode and through another secondary winding of the transformer. The number of turns in the second secondary winding and its polarity ensure that the flyback voltage U.sub.R will be higher than the difference between U.sub.S and U.sub.B.Switching-network components in conjunction with rectifier modulators in television receivers.