A composite
high voltage schottky
rectifier is revealed that provides a
forward voltage slightly larger than a
low voltage schottky
rectifier combined with a
high voltage breakdown capability. The composite
rectifier can be formed from the combination of a
low voltage schottky rectifier, a
high voltage mosfet, and a few small passive components. A quarter bridge primary switching network similar in some ways to a
half bridge primary switching network is revealed. The quarter bridge network consists of four switches with
voltage stress equal to half the line
voltage and the network applies one quarter of the line
voltage to a primary
magnetic circuit element network thereby reducing the number of primary winding turns required to one quarter by comparison to a common
full bridge network. A synchronously switched buck post
regulator is revealed for multi-output forward
converters. The synchronously switched buck post
regulator accomplishes precise independent
load regulation for each output and reduced magnetics volume by using a coupled
inductor with a common core for all outputs plus a second smaller
inductor for each output except the highest voltage output. An improved
capacitor coupled floating gate drive circuit is revealed that provides an effective drive mechanism for a floating or high side switch without the use of
level shifting circuits or magnetic
coupling. The
capacitor coupled floating gate drive circuit is an improvement over prior art
capacitor coupled floating gate drive circuits in that the new circuit uses a
positive current feedback mechanism to reject slowly changing voltage variations that cause unintentional switch state changes in prior art capacitor coupled floating gate drive circuits.