Abstract: Resonant DC-DC converter control circuitry includes a feedback input, a differential integrator, a resonant voltage input, a first comparator, and a second comparator. The differential integrator includes a first input, a second input, a first output, and a second output. The first input is coupled to the feedback input. The second input is coupled to a ground terminal. The first comparator includes a first input coupled to the resonant voltage input, and a second input coupled to the first output of the differential integrator. The second comparator includes a first input coupled to the resonant voltage input, and a second input coupled to the second output of the differential integrator.

Abstract: A system for superplastic forming and diffusion bonding of a metal workpiece sandwich between an upper and lower die to form a structural shape wherein a hollow stainless steel pin is in sealed relationship with a hole in the surface of one metal layer and communicates with the interior of the sandwich. The hollow pin extends into a recess in one of the dies and is in sealing relationship with the recess.