Abstract: A gradient amplifier arrangement is described that comprises a gradient amplifier power stage. The device may be employed to provide a current to a gradient coil, as in a MRI system. The circuitry disclosed includes a series coupling of a first bridge amplifier operating at a first voltage, a second bridge amplifier operating at a second voltage, a third bridge amplifier operating at a third voltage, and a gradient amplifier control stage. The amplifiers may provide output voltages at different levels, and may be switched at different times and frequencies to provide a range of output voltage and current levels.

Abstract: The present invention provides a nano-calorimeter device operable for measuring and characterizing the thermodynamic and other physical properties of materials that are confined to essentially nano-scale dimensions. The nano-calorimeter device including a thin film membrane having a first surface and a second surface. The nano-calorimeter device also including a frame structure disposed adjacent to and in thermal contact with the first surface of the thin film membrane, the frame structure defining a plurality of hollow cells adjacent to and in thermal contact with the first surface of the thin film membrane.

Abstract: A method of operating a system having a coil includes providing a switched amplified current to the coil, and adding a second current to the switched amplified current, wherein the second current is substantially out of phase with the switched amplified current such that the coil receives current with substantially no switching frequency ripple.

Abstract: An ink container that includes a collapsible ink reservoir having first a side and a second side that are opposing, a first spiral conductive coil attached to the first side, a second spiral conductive coil attached to the second side, stiffeners disposed over the first and second coils, and a pressure vessel for pressurizing the outside of the ink reservoir.