接收单元，我们采用的原理和调频收音机原理一样。图3为接收电路，以专用调频接收模块IC1 TDA7021T为核心，经解调后的音频信号从脚输出，送到IC2 LM38...

接收单元，我们采用的原理和调频收音机原理一样。图3为接收电路，以专用调频接收模块IC1 TDA7021T为核心，经解调后的音频信号从脚输出，送到IC2 LM386作功率放大，推动耳机发声。三极管BG9018等组成高频放大级，以提高接收灵敏度。调节可调电容器C23可以改变接收频率，使其对准发射机的发射频率。-Receiving unit, we have adopted the principle and the principle of like FM radio. Figure 3 for the receiver circuit to a dedicated IC1 TDA7021T FM receiver module as the core, after demodulation of the audio signal after the output from the feet, to make IC2 LM386 power amplifier, and promote sound headphones. BG9018 triode composed of high-frequency amplification level in order to improve receiver sensitivity. Conditioning adjustable capacitor C23 can change the receiver frequency so that it fired at the transmitter frequency.

步进电机在测试转速表中的应用.doc