Design Automation Inc. (DAI, Lexington, MA) issued non-exclusive licenses to telecom-power-supplies manufacturers Ascom Energy Systems (Berne, Switzerland) and Tyco Electronics Power Systems (Mesquite, TX) for use of the improved technology in DAI's US Patent 5,198,969, which covers an improved circuit for soft-switching, phase-controlled, full-bridge, dc-dc power converters.
The power converters are used in telecommunications central offices and can be used in all types of electronic equipment requiring more than 300W of voltage-regulated dc power. The patented circuit increases the power-conversion efficiency and reduces the cost and volume of the power converter. The circuit provides capacitive snubbing of the transistor's turn-off switching (reducing power dissipation at turn-off), provides transistor turn-on at zero voltage (eliminating the capacitor-discharge power dissipation at turn-on), and eliminates the severe overshoot of reverse voltage imposed on the rectifier diodes.
