45～870MHz全频道电视伴音接收机的设计

Design of 45～870 MHz all-channel receiver with TV sound

目的突破电视使用的条件，降低能源消耗，方便地收听丰富的电视节目。方法分析了电视机伴音电路的工作原理，利用TDQ-3型全增补高频头、7680中放盒、LM386伴音功放集成电路和CD4022计数／分配器设计了一种45～870MHz全频道电视伴音接收机。结果给出了设计原理图和PCB图。调试表明，灵敏度高，选择性好，可以接收有线电视的全频道电视伴音和部分调频广播节目。结论扩展了电视技术的应用领域。

Aim To make breakthrough in the use of television, lower energy consumption and listen rich television programs conveniently. Methods Analyzing the working principle of television＇s sound circuits, it has designed a kind of 45 -870MHz all-channel sound receiver, using all-added tuner TDQ-3, circuits of TA7680 mediurn-frequency amplifier, the sound power amplifier integrated circuits LM386 and CD4022 integrated counter. Resuits It has given the design schematic and PCB diagram. Through debugging, the circuit is of high sensitivity and selectivity, which could receive the all-channel cable television sound and some FM broadcasts. Conclusion It expands the television technology applications.