输入音频控制继电器的断开与吸合，同时通过可调可调节无音频输入后继电器的延时断开的时间，可延时时间1分钟以内。更换适当电容可延时更长时间。是protel99se画的，已经过量产，欢迎下载。-The input audio control relays to disconnect and pull, adjustable relay delay to disconnect the audio input with adjustable delay time is less than one minu