Hi, Looking at a transformer, primary 12T secondary 200T, step-up The primary is split in two, the secondary in 3, to reduce leakage inductan= ce. ie, 1. L1. Secondary 50T 2. L2. Primary 6T 3. L3. Secondary 50T 4. L4. Secondary 50T 5. L5. Primary 6T 6. L6. Secondary 50T L1 and L3 (secondary) are at opposite sides of the secondary. In which case isn't the direction of the flux changing ? So, when L1 is wound clockwise, shouldn't L3 be wound in a counter-clockwise fashion ? Am I thinking right, or thoughts in the wrong direction ? Apart from the original questions, any thoughts on a better methodology to reduce leakage inductance ? Any thoughts ? Thanks, Manu --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .