Few Questions about Sound on Light

[Electro132]

PNP and NPN transistors are kinda like left hand drive and right hand drive vehicles.

They do pretty much exactly the same thing, but everything is reversed in one compared with the other.

I can't see any reason to use a thyristor.

Hey i did some studies on it and found out it could probably help increase the range for the LED. I've attached a diagram just to make sure it's correct.

 

[Electro132]

Sorry here's the diagram with better references. Take note though that i did not include the resistor values due to me just giving the idea and seeing if it will work with our current project.