This project demonstrates a method of minimising a half-bridge MOSFET's power losses and also minimising the Electromagnetic Emissions. Simulation for the half-bridge and inductor has been simplified and the pictures will open larger so you can read details. I have not seen this solution before but I am sure it is used and is not novel. This project has been well tested in simulation. Although the project is complete if necessary I shall make amend and clarify please leave a note for me below or on my blog.
The project example below has gone through many iterations much more than I would have carried out for a paid for design. The outcome is that the design should have the benefits of resonant mode switch-mode power supply plus working over a wider voltage range or a conventional SMP. I am not anticipating a real commercial use of this project but do contact me I work from home and I can complete the project.
Other applications of the strategy;
The size of a large snubber capacitor connected to the switching junction of a half-bridge drive and inductor is determined by;
1. Whether the inductor flows continually. If the inductor current mode is discontinuous this strategy may not be applicable.
2. If the inductor current varies widely. In this case the capacitor will need to be small or the dead-time large.
3. Should be applicable to an application of Buck/Boost multi-phase or single-phase power supply or amplifier.
Example of multi-phase buck with constant inductor current irrespective of load. In this case it may not be necessary to fit the gate resistor and diode network as shown. The resistor and diode network is a good refinement to protect the power transistors anyway.
Multi-phase buck - See lower half of the page which also shows a PCB layout;
ZVS & ZCS - are other variants of resonate mode. Zero Voltage or Zero current switching respectively. A variation this Arc-lamp power supply is that the capacitor value is changed by transistor switch to suit the different starting and warming up modes of operation of the lamp power supply.
I will not add a half-bridge boost for PFC other strategies are better. It was going to be a design exercise to test capacitor snubber feature rather than a necessary part of the design. That was going to be carried out using Tina-TI.