Hello Guyz! First of all I am new here and I found this section to be appropriated for submitting my question. Well, I was Investigating on Car headlight Alarm and how it should sound a buzzer when the headlights are on? I have attached the circuit diagram aswell you might wanna have a look on it. I found this while i was searching for ideas. Now all I need is lots of suggestion from you guyz regarding to how it can be improved. such as; a pnp transistor has been used can it be improved with a comparator or with any other components? Are there any other components of this circuit which can be improved? How can I make it smaller? I have heard about the surface mount techniques as well as Integrated circuits which can make a circuit smaller But I don't have a clue how they work in reality?. So, I would really appreciate if you guyz could give me a helping hand please?