Issued Patents 1989
Showing 1–5 of 5 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4873602 | Ripple attenuator for AC power transmission line protective relays | — | 1989-10-10 |
| 4825323 | Out-of-step blocking unit | — | 1989-04-25 |
| 4825327 | Negative and zero sequence directional overcurrent unit for AC power transmission line protection | George E. Alexander | 1989-04-25 |
| 4821137 | Positive sequence distance relay for AC power transmission line protection | — | 1989-04-11 |
| 4819119 | Faulted phase selector for single pole tripping and reclosing schemes | — | 1989-04-04 |