US4952884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulse width modulation amplifier circuit
Assignee: Pioneer Corp
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Filing: 1989-08-03
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Granted: 1990-08-28
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Expires: 2009-08-03
Abstract
Abstract A pulse width modulation amplifier circuit pulse modulates a triangular carrier wave with an analog input, and the pulse width modulated signal is amplified and demodulated. To reduce radiated interference, the carrier is first frequency modulated by a random signal.
Inventors
- 👤 Akio Tokumo
- 👤 Masayuki Kato
- 👤 Takeshi Sato
- 👤 Tatsuzo Hasegawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:10
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/20; H03F3/21; H03F3/217; H03F3/2171
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
70 words
In a pulse width modulation amplifier circuit of the type having a carrier frequency generator providing a carrier wave that is pulse width modulated in a pulse width modulator by an input signal, and the pulse width modulated carrier is subsequently amplified and demodulated, the improvement comprising; means for frequency modulating said carrier wave with a random signal prior to said carrier wave being applied to said pulse width modulator.
Claim 2
Dependent Claim
70 words
In a pulse width modulation amplifier circuit of the type having a carrier frequency generator providing a carrier wave that is pulse width modulated in a pulse width modulator by an input signal, and the pulse width modulated carrier is subsequently amplified and demodulated, the improvement comprising; means for frequency modulating said carrier wave with a random signal prior to said carrier wave being applied to said pulse width modulator.
Claim 3
Dependent Claim
82 words
The invention of claim 1, wherein said means comprises, a triangular wave generator for generating a triangular wave output having a frequency dependent upon the frequency of an input triggering signal, an oscillator for providing an oscillator output frequency signal, a random signal source for providing a random frequency signal, an frequency modulator for frequency modulating said oscillator output frequency signal with said random frequency signal and, said frequency modulator output being connected to said triangular wave generator as said triggering signal.
Claim 4
Dependent Claim
15 words
The invention of claims 1 or 2, wherein said random signal is a noise 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) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |