Megahertz direct base drives for high power converters with high voltage bipolar power transistors

In bipolar transistor converters two considerations are usually extremely important. These are low total losses (base drive and main transistor) and compact construction. These considerations first led to the concept of the compensated Darlington power switch, and then the concept of the optimized pulsed transformer coupled direct base drive. The authors discuss the topology of an experimental 1 MHz base drive. The unit is driven off a higher voltage supply in the primary, enabling the use of small FETs as drivers. They discuss the high frequency carrier wave system and then discuss the results of the system implemented in the prototype