Transformer Design Challenges

During my internship, I worked with large transformers and wanted to apply my knowledge by building one myself. My goals were to keep costs as low as possible while maximizing efficiency. I chose a 1/16-inch thick stainless steel sheet to mimic the separated magnetic cores of transformers, aiming to reduce eddy currents. I selected 8-gauge wire to ensure scalability. Additionally, I aimed to complete the transformer within two weeks to present it during my internship.

Building

Building the transformer turned out to be more tedious than I had anticipated. Nonetheless, I persevered and assembled enough sheets to create a 1/2-inch thick, U-shaped core, with a rectangular piece to fit on top. To achieve a step-up transformer, I wound eight times as many loops on the secondary side compared to the primary, expecting eight times the output voltage and 1/8 of the current.

Testing

After building and calculations, it was finally time to test the prototype. I used a safe, low input voltage at Temple's lab to check if the output matched my calculations. While the transformer did work, I found it to be highly inefficient.

Lessons Learned

After consulting with my professors, I discovered a design flaw that significantly impacted the transformer’s efficiency. I had assumed that connecting the two rough-cut edges would allow magnetic flux to flow through. However, I found that most of the flux was circulating within the U-shape itself, leading to a considerable loss in efficiency.