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本解码器以色副载波频率为依据(4.43MHz/3.58MHz)自动识别彩色电视信号的PAL/NTSC制,自动切换并输出一组PAL/NTSC色差信号和一对制式识别控制电压,适于一切彩色解码输出为色差信号的PAL制彩电加制为PAL/NTSC双制式彩电,对于解码IC为AN5622(AN5620)的彩电(包括松下M11机芯),使用本解码器的加制步骤更为简单。 本解码器电路原理如图所示。解码部分借用PAL制专用解码IC(TA7193),经重新设计外围电路,实现NTSC制解码功能,理论根据是:PAL与NTSC制彩电编码信号的主要区别是PAL制还需逐行倒相,只要停止PAL制解码器的逐行倒相,就可利用PAL制的V、U轴解调出NTSC色差信号。多年应用实践也证明,据此设计
The decoder automatically detects the color television signal PAL / NTSC based on the color subcarrier frequency (4.43MHz / 3.58MHz), automatically switches and outputs a set of PAL / NTSC color difference signals and a pair of standard identification control voltages suitable for all Color Decoding The PAL color system is a PAL / NTSC dual color TV. For color TV with AN5622 (AN5620) decoding IC (including M11 Matsushita movement), it is simpler to use this Decoder. The decoder circuit shown in the figure. The decoding part borrows the PAL system-specific decoding IC (TA7193) and redesigns the peripheral circuits to realize the NTSC decoding function. The rationale is that the main difference between the PAL and NTSC color-coded signals is that the PAL system also needs to be phase-by- PAL system decoder line by line, you can use the PAL system V, U axis demodulation NTSC color difference signal. Years of application practice also proved that, based on the design