Theory and Principles Harold Moore Power Transformers H. Jin Sim and Scott H. Digby Distribution Transformers Dudley L. Galloway Underground Distribution Transformers Dan Mulkey Dry Type Transformers Paulette A. Payne Step-Voltage Regulators Craig A. Colopy Reactors Richard Dudley, Antonio Castanheira, and Michael Sharp Instrument Transformers Randy Mullikin and Anthony J. Jonnatti Transformer Connections Dan D. Perco LTC Control and Transformer Paralleling James H. Harlow Loading Power Transformers Robert F. Tillman, Jr. Causes and Effects of Transformer Sound Levels Electrical Bushings Loren B. Wagenaar Load Tap Changers (LTCs) Dieter.