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交流适配器是摄像机的一个附件,它将交流220V电压变成12V/1.2A直流电压,通过多芯电缆直接给摄像机供电,或通过电池夹给电池充电;适配器上的音频/视频输出插孔通过多芯电缆与摄像机相连,将摄像机输出的音频/视频信号经射频调制变成射频信号,最后通过RF OUT插孔输出。 NV-M8000摄像机随机配备的交流适配器电路图如附图所示。这种适配器的型号大多为VW-AM7E,其内部射频调制器型号为ENC47956。ENC47956输出UHF36CH±4.73MHz射频信号,属于PAL G制式。这种制式与我国采用的PAL D/K制式的图像和伴音信号调制方式及极性基本相同,不同之处在于伴音载频与图像载频间距为+5.5MHz,而我国采用的PAL D/K制式标准为+6.5MHz。因此,用PAL G制式传送的射频信号由PAL D/K制电视机重放时就会出现有图像无伴音的现象。这种交流适配器在我国需要改频后才能使用。 这种适配器的改频方法如下:拆开交流适配器外壳,卸出射频调制器屏蔽盒盖,在印制板上找到振荡线圈T1,焊下T1
The AC adapter is an accessory to the camera that converts an AC 220V voltage into a 12V / 1.2A DC voltage, powers the camcorder directly through a multicore cable, or charges the battery through the battery clip; the audio / video output jacks on the adapter pass through more The core cable is connected to the camera and the audio / video signal output from the camera is RF modulated into a radio frequency signal and finally output through the RF OUT jack. NV-M8000 camera comes with the AC adapter circuit as shown in the figure. The type of adapter is mostly VW-AM7E, its internal RF modulator model ENC47956. ENC47956 output UHF36CH ± 4.73MHz RF signals, PAL G standard. This system and our country PAL D / K standard image and audio signal modulation and polarity are basically the same, except that the sound carrier frequency and image carrier frequency spacing of 5.5MHz, and our country used PAL D / K Standard standard is + 6.5MHz. Therefore, the PAL G standard radio frequency signal transmitted by the PAL D / K television set will appear when there is no audio phenomenon. This AC adapter in our country need to change before use. This adapter is as follows: Disassemble the AC adapter shell, remove the RF modulator shield cover, find the oscillation coil T1 on the PCB, the welding T1