| 摘要 |
The simulator enables the luminance level and the level of the synchronising signal to be varied independently. The amplifier comprises a circuit for temporal separation of the synchronising signal from the luminance signal, and an attenuator with two attenuation factors which can be switched over depending on whether the synchronising signal or the luminance signal is applied to it. Each attenuation state is programmable. The separation between synchronising signal and luminance signal is obtained, on the one hand, by aligning the image signal with the backgrounds of the synchronising signal, and on the other hand, by aligning the image signal with one of the front or back porches of the synchronising signal, by then inverting and amplifying the signal aligned with the porches and finally by subtracting the amplified inverted signal with the signal aligned with the synchronising backgrounds. The points of zero value of the subtraction determine the points of front and back separation of the two signals to be separated. <IMAGE>
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