Issued Patents 1989
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4887018 | Line to line to line to neutral converter | — | 1989-12-12 |
| 4876468 | Thyristor driver turn-off circuit | — | 1989-10-24 |
| 4802053 | Control circuitry including phase failure relay | Roger C. Wojtak, John S. Hoelzer | 1989-01-31 |
| 4796142 | Overload protection apparatus for emulating the response of a thermal overload | — | 1989-01-03 |