SQUARE_WAVEFORM_MULTIBURST_GENERATOR

Published:2009/7/6 4:55:00 Author:May | From:SeekIC

The generator described here IS intended for multiburst signal square waveformgeneration and can be used as a device for characterizing the response of TV monitoramplifiers as shown.The circuit is an RC oscillator with NAND gates(IC4-4011)，withits capacitor C changed periodically by means of bilateral switches(IC2，IC3-4016)，Thecontrol inputs of bilateral switches are driven by the outputs of a counter/decoder(IC1-4017)the operation of which is determined by generated clock pulses,SO that theyoccur eight times at half-picture (field).These pulses are locked to vertical blank pulses． Horizontal synchronizatiOn is achieved by means of composite blanking pulses (negative polarization) applied to pms 1 and 5 of IC4，The oscillator frequency changesh the following(liscrete steps：460 kHz，680 kHz，900 kHz，1400 kHz，2700 kHz，3600kHz，for the time of one frame。The video signal is fed on a mlxer where it is superimposedwith a composite sync signal.



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