Development of World’s First Inverter Driven Commercial Freezer with CO2 Refrigerant by SANYO
Conventional CO2 refrigerant circuit become supercritical plus the coefficient of performance (COP) drops to less than HFC based refrigerant circuit when operating under high ambient temperatures such as summer temperature of above 30 degrees Celsius. In response to overcome this problem, Sanyo Electric developed a world’s first inverter driven commercial freezer with CO2 refrigerant. The new freezer was developed based on Sanyo’s patented split cycle which uses company’s proprietary Two Stage Rotary CO2 Compressor resulting in significant improvement in COP exceeding the performance of HFC based refrigerant circuit. Read more
Development of World’s First Low-Resistance 300A single-Chip SiC Trench MOSFET by ROHM
The inherent deficiency of silicon semiconductor devices during power conversion has forced many designers to look for alternative semiconductor material. One such material is silicon carbide due to its superior material properties leading to increase in power conversion efficiency in these type of devices. Power conversion modules for such application as electric vehicles,power transmission and railroads require a minimum current capacity of approximately 600A which is currently possible through parallel connection of several large area Si chip capable of outputting 200A to 300A. In order to increase current is necessary to reduce ON resistance while at the same time increasing the surface area of the chip. Even though the SiC features an excellent ON resistance characteristics increasing the area results in a greater number of crystal defects which leads to device failure. Read more
