SteveBzz,
I asked myself the same question, and I do not have the answer. Perhaps because of the law of big quantities. The thing is that if you try to buy a LASER LED , you still need lenses to colimate it and all this can end in 15 to 20 bucks plus all the hasle of the optical aligment and...
I am using a laser pointer for parking purposes in my garage. It is now activated by having the power in parallel with the opener lamp. However, I wanted it more smart and thought about using a sound detector to detect the noise from the engine. I was playing with an LM-324. I put up to three...