情境
Design a simple alarm system using a PIR motion sensor that activates a buzzer upon detecting movement. The circuit is battery-operated for portable use.
這張圖裡有什麼
看懂背後的決策。
01
Used an NPN BJT as a switch to drive the buzzer
02
Included a base resistor to limit current from the PIR output
03
Added a bypass capacitor for noise filtering from the battery
Suitable for DIY home security projects, low-power motion detection alerts, and educational prototyping.