Government regulations stipulate that garage door opener sensors must have safety devices installed to prevent accidents. Garage doors with remote sensors allow the homeowner to remotely access and open or close their garage door, either from their home or their car.
Garage door openers have infra-red radio wave signals installed into the receiver end and the remote-controlled end. As with a TV remote, the infra-red signal sent by the garage door remote control carries the waves across to the receiver inside the garage. The receiver is wired to the garage door opener and in turn, when the remote control is activated, the signal tells the door to open. The sensor switch receivers are usually found just inside the garage door, very close to the ground.
Garage door sensors can also be hard wired into the home, so that before you leave you can open your garage door via a switch, which sends a signal to the remote receiver. The door then opens automatically so that you can drive your car from the garage. At the same time, you can press the remote control device from your car to close the garage door as you leave.