Arc Welding Diodes

These five new ultra-fast recovery diodes are specifically developed to increase power and improve reliability and efficiency in high-frequency (HF) inverter welder output stages. Faster output stage rectifiers enable higher welding frequencies, which, in turn, make bulky magnetic components such as transformers and coils smaller, less expensive and more reliable. Reducing magnetic component size contributes to overall welding equipment efficiency and reliability.

Typical voltage and current requirements for arc welders are 20-50V at 50-500A DC with low ripple for optimum weld quality. Many discrete diodes are limited to 60A, but most welders are rated for continuous operation at more than 60A.

Four of the five new welding diodes, the 80EBU02, 150EBU02, 80EBU04 and 150EBU04, are available in the manufacturer's POWIRTAB package, and are rated at 80A. The devices help reduce parallel package count by a factor of two to three, reducing assembly cost and improving reliability. The fifth device, 60EPU02, is rated at 60A and is packaged in the industry-standard TO-247 package, for mounting flexibility in existing designs.

These diodes are best suited for high-current arc welding applications. Internally, the large anode tab allows more wire bonds to the silicon die chip, which helps improve forward voltage drop and increase surge-handling capability to as high as 1600A. The POWIRTAB package is designed for mounting flexibility and assembly ease for either printed circuit board or bus bar construction. The tab does not transfer mounting torque to the plastic case, and prevents costly mechanical failure.

International Rectifier, 233 Kansas Street, El Segundo, CA 90245. Tel: 310-252-7105; Fax: 310-252-7171.