[Itay] has a friend who works in a rented office where the parking lot is secured by a remote-controlled gate. Unfortunately, while his friend shares an office with several people, they only received a single remote. To help his friends out, he built a small device that triggers the remote control whenever a phone call is received.
The remote modification was rather straightforward. He simply opened the device, adding a single wire to each button terminal. Rather than connect to the remote using wires, he decided to fit it with what looks like a scavenged DC power jack. The ring detector circuitry was constructed and stuffed in a small phone box, which is connected to the remote using a DC power plug. It’s a great solution to the problem, but let’s just hope no one gets a hold of the phone number they used for the trigger!
There are plenty of pictures on his site, as well as video of the ring detector being tested. Unfortunately [Itay] lost the original schematics for the circuit, so you will have to flesh that part out on your own if you wish to build a similar device.
Keep reading to see a few videos of the remote in testing and in use.