Three phase transformers are commonly used for powering DC brushless motors in conjunction with 3-phase, alternating current power systems. The power transformer is a key component of the conversion system. Its design is critical in reducing the weight and size of the motor driver. Minimizing a motor driver’s weight and size is crucial for many applications, particularly in the automotive and aerospace fields. A new, innovative, and patented transformer core construction is covered in the presentation. This construction significantly reduces the transformer’s core weight. Different core materials for minimizing the total transformer weight are discussed and compared. The achievable weight reduction is over 30% in comparison to established design and manufacturing techniques.