METHOD FOR SCRAMBLING OF TV-SIGNAL AND DEVICE FOR IMPLEMENTATION OF SAID METHOD Russian patent published in 1995 - IPC

FIELD: TV devices. SUBSTANCE: device has TV program source, which output is connected to TV signal modulator and to control unit, which gate pulses output is connected to input of false pulses and synchronization pulses. In addition device has power amplifier, which output serves as output of transmitting part of TV signal scrambling device, unit for input and storage of codes, first and second adders, modulator of control signals. Control output of control unit is connected to synchronization input of unit for input and storage of codes. Output of generator of false pulses and synchronization pulses is connected to second input of first adder, which output is connected to first input of second adder through modulator of control signals. Output of modulator of TV signal is connected to second input of second adder, which output is connected to input of power amplifier. Receiving part of device has amplitude modulator and wide-band amplifier, which are connected in series. Output of wide-band amplifier serves as output of TV signal scrambling device. In addition device has selective amplifier, detector, comparator, synchronization pulse selector, switch, code comparison unit, accumulator, timer, controlled gate. Output of wide-band amplifier is connected to signal inputs of switch and synchronization pulse selector through serial circuit of selective amplifier, detector and comparator. Signal output of synchronization pulse selector is connected to control input of switch. One of switch outputs is connected to control input of gate through code comparison unit, pulse accumulator and timer. Another output of switch is connected to signal input of gate, which output is connected to control input of amplitude modulator. EFFECT: increased functional capabilities. 2 cl, 3 dwg