areas of expertise: power supply design, ac/dc, dc/dc, hv, power levels up to 50KW. control systems design, analog and digital. transformer design, ferrites, tape cores, mpp cores, powder cores, etc. battery backup systems, data center hold-over, notebooks, single cell products. analog instrumentation. Audio amplifier design, class AB, B, D, minimum feedback design. Loudspeaker design, vented, closed box, parameter analysis, tuning, optimization.