2020. The system employs an infra-red radio signal, which activates the electric motor once the button is pressed on your remote. Each of our eight offices have been strategically located to meet your garage door needs in a timely and cost effective way. When the switch opens, the two parts separate, causing the electrical current to stop and the circuit to deactivate. These have faster response and easy pattern measurements. This device emits and/or detects infrared radiation to sense a particular phase in the environment.