Abstract: An enhanced split cooling system for a turbocharger and an engine includes an oil cooler, a three-way valve assembly and a four-way valve assembly for controlling the flow of coolant, and radiators and subcoolers, for controlling coolant temperature. The valve assemblies are independently controllable to direct coolant through an oil cooler and a turbocharger intercooler either directly from the engine if the oil cooler and intercooler require heating or from the radiators and subcoolers if the oil cooler and intercooler require cooling. Depending upon the engine operating temperature, the valve assemblies can be configured to establish at least three different coolant processing modes.

Abstract: Switching losses are distributed equally between multiple switching devices in a rectifier bridge (50) in which the rectifier bridge comprises at least a first pair of serially connected switching devices (56A, 56B) connected between positive and negative DC output buses (52, 54) and a second pair of serially connected switching devices (58A, 58B) connected in parallel with the first pair of switching devices. Only one of the switching devices in each pair of switching devices is pulse width modulated at any time at a frequency substantially higher than a frequency of the AC power applied to the rectifier bridge while another of the switching devices in each pair of switching devices is operated in synchronism with the waveform of the AC power applied to the bridge. Operation further involves periodically alternating the PWM operation of the switching devices between switching devices in each pair of switching devices so as to distribute the losses.