There are many uses for RFID such as supply chain management, but access control is one of the most relevant applications for personal use. Many people use RFID access cards to get into buildings, use elevators, or even open the doors to those special penthouse type hotel suites. Setting up your own front door (or any door for that matter) with an RFID enabled access mechanism is pretty easy.

Most access control solutions use an electronic door strike, which gives way when activated so you don't have to unlock or turn the doorknob; you just push (or pull) the door open. This is exactly what's used to "buzz" someone in a door. That buzzing sound is AC power rushing through the magnetic coil windings in the door strike, pulling up and vibrating the pin that normally keeps the strike in the closed and locked position. You're going to use DC power to operate your electronic strike, so all you should hear is a slight click.

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