Railway circuit for sending signalling information along a railway line to a vehicle travelling along the railway line

A railway circuit for sending signalling information along a railway line to a vehicle travelling along the railway line, the railway circuit comprising:

• first signal generator means suitable for generating an alternating signal with a varying voltage supplied to a first conductor that comprises sections arranged adjacent to and within respective portions of a first and a second rail facing towards the inside and belonging to a railway circuit to define at least an inner first coil magnetically coupled with the first and the second rail;
• signal receiver means suitable for receiving said alternating signal present on said railway circuit by means of a second coil, wherein a second conductor comprises sections arranged adjacent to respective inner portions of the first and second rail and magnetically coupled with said rails, the signal receiver means being suitable to detect a condition of signal received null or below a threshold when said rails are short-circuited by at least one axle of a railway vehicle present on said railway circuit;
• and
• second signal generator means suitable for generating a signal with variable current on the basis of a modulation code associated with said signalling information;
• said signal being supplied to a third conductor which comprises sections arranged adjacent to respective outer portions of the first and the second rail facing towards the outside to define at least an outer third coil coaxial and external to the inner first coil and magnetically coupled with the first and the second rail;
• wherein said second signal generator means being suitable to induce on the electric circuit, formed by the portions of the first and the second rail short-circuited by said axle, a variable current modulated by said code;
• said railway vehicle being provided with current detector means suitable for detecting said variable current for extraction of said code and sending of said signalling information.