Hidden symmetries in 5D supergravities and black rings

We construct generating technique for 5D minimal and $U(1)^3$ supergravities based on hidden symmetries arising in dimensional reduction to three dimensions. In the three-vector case the symmetry is SO(4,4), and the minimal case corresponds to contraction of this group to $G_{2(2)}$. The matrix representation is presented applicable to both cases and the generating transformations preserving an asymptotic structure are listed. Our transformations contain enough free parameters to construct the general charged black ring in $U(1)^3$ theory starting with known solutions. To avoid a complicated inverse dualisation in the component form we introduce the matrix-valued dualisation which opens the way to derive new solutions purely algebraically from the coset representation of the seed.