An electromechanical lock includes a lever coupled with a locking mechanism configured to receive mechanical power from an user, and to output the mechanical power to mechanically disengage the locking mechanism provided that a support of the fulcrum is in an open position, and a return mechanism for the support of the fulcrum including a reset spring whose other end is configured to, during the reception of the mechanical power from the user, move past the support of the fulcrum with the mechanical power outputted by the lever, and, finally, force the support of the fulcrum with the mechanical energy outputted by the return spring through the lever back to a locked position.

Passive lock assemblies that can be locked and unlocked by a mobile device are disclosed. Embodiments may include a lock assembly that includes an optical-to-electrical converter device, a key reader, and a processor. The optical-to-electrical converter device is configured to generate an electrical signal when illuminated by light produced by a mobile device. The key reader is configured to be powered by the electrical signal and, when powered, to read a key encoded in the light and to generate a key signal in accordance with the key. The processor is configured to be powered by the electrical signal and, when powered, receive the key signal and determine a validity of the key in accordance with the key signal. The processor is further configured to, when powered and the key is valid, generate a switch signal.