Electromagnetic field adjustment for proximity detection

A method for adjusting the resonance of a magnetic field generator, comprising:

• installing a magnetic field generator at a location at which the magnetic field generator is to be used, the magnetic field generator comprising:
• a signal generator for outputting a voltage,
• a magnetic field generating circuit for generating a magnetic field, wherein the magnetic field generating circuit comprises:
• a capacitor, and
• an inductor comprising a ferrite core, and
• a shunt movably supported relative to the inductor such that moving the shunt changes a value of inductance in the magnetic field generating circuit, and
• moving the shunt relative to the inductor to increase the resonance of the magnetic field generating circuit for a given voltage.

A proximity detection system, comprising:

• a plurality of alarm devices for detecting a magnetic field, and
• a magnetic field generator comprising:
• a signal generator for outputting a voltage,
• a capacitor in electronic communication with the signal generator,
• an inductor in electronic communication with the capacitor,
• a ferrite core at least partially surrounded by the inductor, and
• a shunt movably supported relative to the inductor such that moving the shunt changes a value of inductance in the magnetic field generator.

A method for adjusting the range of a magnetic field generated by a magnetic field generator for a proximity detection system, comprising:

• installing a magnetic field generator at a location,
• positioning a personal alarm device at a distance from the magnetic field generator,
• generating a magnetic field using the magnetic field generator, wherein the magnetic field encompasses the personal alarm device,
• detecting the magnetic field with the personal alarm device,
• decreasing the magnetic field size until the personal alarm device cannot detect the magnetic field,
• incrementally increasing the magnetic field size until the personal alarm device detects the magnetic field, and
• setting the magnetic field size equal to the magnetic field size at which the personal alarm device detected the magnetic field.

A method for adjusting the range of a magnetic field generated by a magnetic field generator for a proximity detection system, comprising:

• installing a magnetic field generator at a location,
• selecting a power level of the magnetic field generator less than the maximum power level of the magnetic field generator,
• generating a magnetic field by operating the magnetic field generator at the selected power level,
• adjusting the position of a shunt relative to the magnetic field generator to maximize the size of the magnetic field generated by the magnetic field generator at the selected power level,
• positioning a personal alarm device at a distance from the magnetic field generator, and
• adjusting the magnetic field generator to generate a magnetic field having a boundry located at approximately the distance of the personal alarm device.

A proximity detection system comprising:

• a first magnetic field generator for generating a first oscillating magnetic field, wherein the first magnetic field generator is arranged on a first vehicle,
• a second magnetic field generator for generating a second oscillating magnetic field, wherein the second magnetic field generator is arranged on a second vehicle,
• a first magnetic field detector capable of detecting the second oscillating magnetic field and providing a visual and/or audible warning to an operator of the first vehicle upon detecting the second oscillating magnetic field, wherein the first magnetic field detector is arranged on the first vehicle, and
• a second magnetic field detector capable of detecting the first oscillating magnetic field and providing a visual and/or audible warning to an operator of the second vehicle upon detecting the first oscillating magnetic field, wherein the second magnetic field detector is arranged on the second vehicle.