We have several brand new military surplus NSN: 5950-00-496-3502 Keytronics K-6166 Power Transformers each with 18 tabs that are about 3-1/2" x 3" x 2-1/2" and weigh roughly 3-1/2 lbs. each. originally used by the Dept of the Navy and France but we aren’t sure what they were used in, what they were used for, and what the alternate uses of these might be today. Any info would be hugely helpful thank you
Based on this link, you appear to have a relatively tiny three-phase wye to delta transformer.
This 400 Hz transformer is likely an aircraft component. If I were to speculate, having many independent secondaries allows a single transformer to drive many devices with the understanding that each circuit has its own circuit protection.
This is a highly specialized transformer. I can offer no recommendations for alternative use. Perhaps you can follow online auctions to see if there is niche application.
Thank you for your time and the input!