The quantum physics of superconducting circuits will be applied in new ways to realize circuits where the single charge quantum plays the dual role of the flux quantum in classical Josephson junction circuits. Building on the recent advances in superconducting quantum bit circuits, we will theoretically model, design, fabricate and measure a specific set of circuits which probe the little-explored regime of equally strong Josephson and charging energies, yet well isolated from dissipation so as to achieve strong quantum behavior of the phase or charge. Our objectives are: To realize frequency to current conversion at larger currents than presently achieved and in a way which is immune to fluctuations; to investigate new types of quantum-limited measurement schemes which exploit nonlinearities arising from quantum inductive and quantum capacitive effects; to understand and apply the nonlinear dynamics of quasicharge and charge solitons for oscillators and current sources with unique characteristics. The 36 month project will contribute to the long term development of quantum ICT, where impact on such areas as ultra low noise microwave signal amplification, qubit measurement and manipulation, and quantum metrology is expected.