if you look at a transistor radio, that should be obvious: because you would start to fry the environment if you were to send radio waves at a couple of gigawatts, just so your radio at distance x could pick up the signal and play it at an audible level without having to amplify it 🙂
Also, low power signals are much easier to handle. They don’t cause as much interference, you can use thinner conductors and put them closer together.
Say you have a signal that goes rapidly changes from 0 V to 1 V. Then you add a 10 V battery to add to that voltage – you now have a signal that goes from 10 V to 11 V instead. That isn’t any more useful than the signal you started with.
An amplifier doesn’t add voltage, it multiplies it. So If you put in 1 V into a 10x amplifier, it puts out 10 V, and if you put in 0 V, it puts out 0 V as well.
Latest Answers