Supply circuit for air intake manifold collector of a vehicle combustion engine

The circuit has a mixer (30) with two ducts (54, 56) connected to two branches (20, 24) and entering into a duct (58) connected to an air inlet manifold (16). The ducts (54, 56) have closing units (60, 62), at their junction with duct (58). The closing units are activated by a common control unit and are synchronized inversely with respect to each other to mix air from the branches to give a determined temperature to the air.