Have you ever gone to get the car out of the garage and found that you left the door open all night? With luck, the car is still there and everything inside the garage untouched. You breath a sigh of relief and vow to be more careful in future.

But what if the car had been stolen? How would you square that with the insurance company when you declared that the car is left overnight "in a secure garage"? What about the expensive power tools, bicycles, and gardening equipment you keep there?

This Garage Link circuit helps to prevent the garage door (or either door in the case of a double garage having twin doors) being left open all night. It works by establishing a radio link between the garage transmitter and some point inside the house. The indoor receiver then provides an audible warning in the form of a short bleep every 45 seconds.