摘要： 1.蜂鸣器Buzzer 关键参数： D12mm, H9mm 封装尺寸 : 要根据PCB板大小选封装 Magnetic Transducer 电磁 ：根据价格和应用场景选类型，有源的比无源的贵。 2,400Hz 驱动频率, 单片机I/O 控制，可以通过PWM控制，也可以用高低电平控制(不推荐，可靠性不 阅读全文

摘要： The cylinder is a crucial part of the washing machine His debonair dismissal of my inquiry concerning his financial situation led me to believe that n 阅读全文

摘要： There is "no realistic prospect" of the government meeting its own deadline to install smart meters, according to the National Audit Office (NAO).The 阅读全文