A poppet mounted concentrically on a barrel for axial travel downstream relative thereto from an open to closed position, the poppet biased by a coil sprint to its open position. The power supply directly couples, without an output transformer, the output from a full-bridge converter that operates at an output frequency in the range from ten Hz to ten kHz. A second clamping jaw is displaceably arranged on said rail. A machine learning algorithm is used to generate a constitutive relationship that provides a solution to fluid flow through the flux interface.