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一、简易留言器 PT-8820I/O为美国产品,见图1。内部电路原理框图见图2。其引脚功能分别为:1脚为外部线路信号输入,2、3脚接喇叭RL,4脚接VCC,5脚接GND,6脚为REC键(录音),7脚接LED,8脚为PLAY键(放音)。其供电电压4～7V,录音时
First, a simple voice mail PT-8820I / O for the United States products, shown in Figure 1. The internal circuit block diagram shown in Figure 2. The pin functions are as follows: 1 pin for the external line signal input, 2, 3 feet connected to the speaker RL, 4 feet to VCC, 5 feet to GND, 6 feet for the REC button (recording), 7 feet then LED, 8 feet PLAY button (playback). The power supply voltage 4 ~ 7V, recording time