Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5646491 | Electrical motor with a differential phase back EMF sensing circuit for sensing rotor position | David M. Erdman | 1997-07-08 |
| 5473497 | Electronic motor load sensing device | — | 1995-12-05 |
| 5023527 | Control circuits, electronically commutated motor systems and methods | David M. Erdman, Amritlal H. Patel | 1991-06-11 |