The mid-frequency direct current (MFDC) resistance welder incorporates a fast rise time (FRT) transformer. The FRT-MFDC machine is ideal for welding applications requiring short weld times and high welding current. FRT-MFDC welders offer the following benefits: reduced life-cycle cost, better process control for welding coated parts, weld nugget management, minimized heat-affected zone (HAZ) and lower primary power requirements. As a result, the equipment is suited for the following applications: galvanized steels; aluminum; high-strength, low-alloy (HSLA) steels; hot-stamped boron materials; and hot-dipped materials.