Remote controlled garage doors add extra security to our homes, and form the frontline measure in any comprehensive security plan, well before the need for guns, or to buy AR15 related accessories, and ammo. However, with constant use, these controls will start to fail again and again.

The remote control, an RF transmitter

Firstly, it is important to comment on how these devices work, as this may prevent misuse, which often causes frequent defects.

The operation of the control

When the user presses a button on the remote control, the internal battery should power the circuit and start transmitting a code, several times per second. As long as the person keeps the button pressed, the codes will be transmitted. But there is a small initial time until signal stabilization, where there may be no transmission.

Each code consists of a specific pulse train, separated by an unsigned interval, to allow recognition of its beginning and end by the receiver. The pulses must have sufficient power to reach the receiving and control stage, which is next to the gate motor.

The receiver is like a radio, which listens to the RF waves that reach its antenna. He must pick up these weak signals transmitted by the remote, amplify them, select them, convert them into digital codes and compare them with the code stored in his memory. Only when the code is recognized as fit will the gate motor be activated. Regarding the Garage door repair you will be getting the perfect options now.

The Factors

Various factors, such as instability of the transmitter’s supply voltage, or reflections and interferences on the signal, which constitute the transmission and reception environment, may affect signal quality to a greater or lesser degree. Looking more closely at Figure 2, it is possible to note that the pulse sequences are different from each other, especially at the beginning of each code. This may have been caused by some random, uncontrolled situation in the test.

Concerning radiofrequency, it is important to know that objects larger than the wavelength of the signal will reflect it. For example, the frequency of 433 MHz has an approximate wavelength of 70cm. Any object larger than this will reflect signals from this frequency, especially if it is metallic. For more information on antennas and the propagation of electromagnetic waves, refer to references.

It can be seen, therefore, that the work of the receiver is astonishing, since he can discern and recognize the signal destined for him, despite all difficulties and interferences.

The security

At the very beginning of the automated gate controls, only the transmission of some RF frequency was performed, which, when identified by the receiver, triggered the motor. There was no coding of any sort, not least because there were very few devices of this type and the manufacturing was more handmade. With the increase in the number of these devices and the concern for security, the first commercial coding systems appeared, many of them still used today.