Inductive circuit sensor system and method

A method for detecting a security breach of a protected element, comprising:

• generating a signal by the microcontroller;
• transmitting the signal to an inductive sensing circuit;
• querying whether the digital pattern is received and:
• in response to the signal not being received, generating a first alarm condition;
• and
• in response to the signal being received:
• querying whether the received signal is less than a predetermined upper limit and:
• in response to the received signal exceeding the upper limit, generating a second alarm condition;
• in response to the received signal being less than the upper limit, querying whether the signal exceeds a predetermined lower limit;
• and
• in response to determining the received signal to be less that the lower limit, generating a third alarm condition.

A door frame assembly comprising:

• a door, the door being attached to the door frame assembly to move the door between an open and closed position;
• an electrical conductor to transmit power to a first coil;
• and
• a monitoring circuit comprising:
• a second coil being disposed on door opposite the first coil, and inductively coupled with the first coil for receiving the input power;
• an output of the second coil in communication with a serpentine conductive path disposed in the door, the serpentine conductive path arranged to cover a predetermined surface area of the door, the serpentine conductive path conducts the signal through the door to a third coil, the third coil positioned on the door, the third coil further connected to an output terminal of the serpentine conductive path;
• a coil signal being electromagnetically coupled by the third coil to a fourth coil;
• the fourth coil being in communication with an alarm circuit via a return conductor in door frame;
• wherein an air gap separating the first coil and the second coil being maintained at less than or equal to a predetermined distance of separation such that when the first coil and the second coil are separated by a distance greater than the predetermined distance of separation, the magnetic coupling is interrupted and the received signal Rx does not equal the transmitted signal Tx when sensed by a microcontroller in communication with the serpentine conductive path.