A circuit for feeding a fluid to an inflatable chamber, comprising: a compressor (2) a two-way and two-position solenoid valve (3) provided with a first port (31) and a second port (32) and operable between an open configuration, in which the ports (31,32) are in communication with one another, and a closed configuration, in which at least the second port (32) is closed a first conduit (11) connecting the compressor (2) and the solenoid valve (3) a second conduit (12) connected to the solenoid valve (3) and predisposed for being connected to an inflatable chamber a pressure detector (P) arranged for measuring the pressure inside the second conduit (12) a control module (M) arranged for receiving a pressure signal of the detector (P) and for controlling the solenoid valve (3) and the compressor (2) a vent opening (A) arranged along the first conduit (11).