US Patent 10240365 Electronic lock system having proximity mobile device

An electronic lock, such as a deadbolt, with a locking device movable between a locked position and an unlocked position. The lock includes a key fob including a RFID circuit indicative of a valid access code for the locking device. A circuit is provided that is configured to control movement of the locking device between the locked position and the unlocked position. The circuit includes a sensor, such as a contract sensor or a proximity sensor, which detects when a user is within range of a RFID device. When this happens, the sensor is configured to generate an electrical signal, which is used to activate the RFID device for a predetermined period of time. If the RFID device reads a valid access code, the device is unlocked.