This was for a commercial intelligent compact battery charger - 35VDC max 10A out max, one mosfet or igbt with low side drive, 3 o/p diodes, one carefully designed transformer with low leakage, hence minimal snubbers or RCD clamp, internal h/sink to 0VHVDC so no emc problems, 2nd wrap around h/sink for diodes (low Vf), minimal CM and DM filtering needed to comply with EMC, could be two wire or 3 wire mains input... many thousands made with good margin... Regards, Orson Cart.