Location History:
- Hitachi, JP (1978 - 1981)
- Funabashi, JP (1989)
Company Filing History:
Years Active: 1978-1989
Title: Innovations of Tadashi Okawa
Introduction
Tadashi Okawa is a notable inventor based in Hitachi, Japan. He has made significant contributions to the field of technology, particularly in the development of advanced measuring apparatuses and current source inverters. With a total of 4 patents to his name, Okawa continues to push the boundaries of innovation.
Latest Patents
One of his latest patents is a rotating speed measuring apparatus that features a corrector for low and high speeds. This invention utilizes a signal whose frequency is proportional to the rotational speed of a rotor. The design ensures that the rising and falling angles near points crossing zero become larger with the rotor's speed, allowing for the production of a first signal of amplitude corresponding to these angles and a second signal of amplitude corresponding to the frequency. The difference between these signals is evaluated, leading to corrections in either the first or second signals.
Another significant patent is the twelve-step current source inverter. This invention includes a configuration where at least one smoothing reactor is connected to the positive terminal of a DC source. The design incorporates first and second interphase reactors, each connected to the positive and negative terminals of the DC source, respectively. The inverters are designed to supply first-phase, second-phase, and third-phase output currents to a load, with a control unit that shapes the waveform of each output current into a rectangular waveform.
Career Highlights
Tadashi Okawa is associated with Hitachi, Ltd., a leading company in technology and innovation. His work has contributed to the advancement of electrical engineering and measurement technologies.
Collaborations
Okawa has collaborated with notable coworkers such as Yasuo Matsuda and Mitsuyuki Honbu, further enhancing the innovative efforts at Hitachi.
Conclusion
Tadashi Okawa's contributions to technology through his patents reflect his commitment to innovation and excellence. His work continues to influence the fields of measurement and electrical engineering.