Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4870339 | Variable-speed power generating system | Yosio Furukawa, Yasuhiro Yasaka, Osamu Nagura, Hiroto Nakagawa, Yasuteru Oono | 1989-09-26 |
| 4823018 | Control system for variable speed water-wheel generator apparatus | Takao Kuwabara, Akira Bando, Hiroto Nakagawa | 1989-04-18 |
| 4812729 | Protecting apparatus for secondary excitation type variable speed AC generator/motor | Akio Ito, Hidenori Sawa, Hiroshi Sugisaka, Shigeaki Hayashi, Hiroto Nakagawa +1 more | 1989-03-14 |