Designing a PIR Motion Sensor w/ BC-547 Transistor

[suryakalpo]

I'm planning to design a PIR motion sensor. I wanted to know if I can use ordinary class-A amplifiers to amplify the output of the sensor which will be given to the alarm circuit. The transistor I'm planning to use is BC-547

 

[berkeman]

I'm planning to design a PIR motion sensor. I wanted to know if I can use ordinary class-A amplifiers to amplify the output of the sensor which will be given to the alarm circuit. The transistor I'm planning to use is BC-547

Sure.

Is there a reason you wouldn't want to use a class-A amplifier topology? This is all low-power...