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US4628475A
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Pulse width modulation pulse generator
Assignee: Hitachi Ltd
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Filing: 1984-02-03
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Granted: 1986-12-09
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Expires: 2004-02-03
Abstract
Abstract A modulating wave signal whose phase abruptly changes is compared with a carrier signal to generate a pulse width modulation pulse. The carrier signal is a sine wave signal having a frequency n times as high as that of the modulating signal and synchronized with the modulating signal. A phase of the carrier abruptly changes by a factor of n as the phase of the modulating signal abruptly changes. Thus, a pulse with modulation pulse which causes an output voltage of a pulse with modulation inverter to be sinusoidal is generated even if the phase of the modulating wave signal abruptly changes.
Inventors
- 👤 Noboru Azusawa
- 👤 Hisayoshi Shiraishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:49
CPC Classifications
H; H03; H03K; H03K7/00; H03K7/08; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/525; H02M7/527; H02P; H02P21/00; H02P21/06; H02P21/08; H02P21/09
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
104 words
A pulse width modulation pulse generator comprising: modulating wave generating means for generating a sine wave modulating signal which forms a fundamental component of an output voltage of a pulse width modulation inverter; carrier generating means for generating a sine wave carrier signal which is at a frequency n times as high as a frequency of said sine wave modulating signal and synchronized with said sine wave modulating signal; and comparison means connected to said modulating wave generating means and said carrier generating means for comparing said sine wave modulating signal with said sine wave carrier signal to generate a pulse width modulation pulse.
Claim 2
Dependent Claim
104 words
A pulse width modulation pulse generator comprising: modulating wave generating means for generating a sine wave modulating signal which forms a fundamental component of an output voltage of a pulse width modulation inverter; carrier generating means for generating a sine wave carrier signal which is at a frequency n times as high as a frequency of said sine wave modulating signal and synchronized with said sine wave modulating signal; and comparison means connected to said modulating wave generating means and said carrier generating means for comparing said sine wave modulating signal with said sine wave carrier signal to generate a pulse width modulation pulse.
Claim 3
Dependent Claim
58 words
A pulse width modulation pulse generator according to claim 1, wherein said carrier generating means changes a phase of said sine wave carrier signal in synchronism with a change of a phase of said sine wave modulating signal, the change of the phase of said carrier signal being n times as large as that of said modulating signal.
Claim 4
Dependent Claim
32 words
A pulse width modulation pulse generator according to claim 1, wherein said carrier generating means changes a frequency of said carrier signal in inverse proportion to a frequency of said modulating signal.
Claim 5
Dependent Claim
29 words
A pulse width modulation pulse generator according to claim 1, wherein an amplitude of said sine wave carrier signal is larger than that of said sine wave modulating signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-08 | 1990-06-09 | 1990-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-08 | 1994-06-09 | 1994-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-08 | 1998-06-09 | 1998-12-09 | $7700.00 | Window Closed / Lapsed |