Hello i was wondering how i could transmit a signal to a receiver to tell a LED to light up? Thats basically the question. The whole project is this, to build a laser alarm system. I already know how to set up the laser system i want build. That was the simple part but how would i lest expensively build a system where when the laser is broken it transmits to a receiver turning on LED. And i would like for the transmitter range to be able to cover an acre. thanks any ideas will be great.