Someday I goes to visit a friend. He begs me helps to seek electric bell front door circuit. In model to be simple, use the a little equipment. I then choose the Door Buzzer circuit this give. Because of use , IC NE555 produce electric bell sound and use IC LM386 for amplify talk at one time. For R1 use fine decorate the sound as you like it. request have fun this circuit.
　　有一天我去看望一個(ge) 朋友。他請求我幫助設計一個(ge) 電鈴門電路。要求小巧而且電路簡單。然後我選擇我選擇了揚聲器產(chan) 生聲音的電路個(ge) 他設計。使用NE555產(chan) 生門鈴信號和使用LM386對門鈴信號進行放大。通過調節R1的電阻阻值可以調節門鈴聲音。