Issued Patents 1989
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4873620 | Voltage supply with recovery protection for a thyristor | Helmut Schummer, Gerhard Donig, Walter Schmidt | 1989-10-10 |
| 4808200 | Electrostatic precipitator power supply | Richard Dallhammer, Walter Schmidt, Helmut Schummer | 1989-02-28 |