US4532435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulse width modulator having nonlinear transfer function
Assignee: EMC Corp
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Filing: 1982-07-09
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Granted: 1985-07-30
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Expires: 2002-07-09
Abstract
Abstract A pulse width modulator circuit for use with DC power converters. The circuit contains an oscillator having a nonlinear output, a first comparator for comparing the output of the oscillator with an input voltage, and a second comparator for selecting portions of the output waveform of the first comparator for supplying to the output of the modulator.
Inventors
- 👤 Jonathan R. Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:40
CPC Classifications
H; H03; H03K; H03K7/00; H03K7/08; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/33538; H02M3/33546
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
118 words
Apparatus for providing a pulse width modulated waveform responsive to an input voltage, said apparatus comprising: oscillator means for generating an output signal, said signal having alternate first portions, during each of which the output signal rises along a first path from a first voltage value to a second voltage value, and second portions, during each of which the output signal falls along a second path from said second value to said first value, at least one of said paths being nonlinear; means for comparing said output of said oscillator means with said input voltage; and means for supplying a waveform representative of selected portions of the output of said comparing means to the output of said apparatus.
Claim 2
Dependent Claim
118 words
Apparatus for providing a pulse width modulated waveform responsive to an input voltage, said apparatus comprising: oscillator means for generating an output signal, said signal having alternate first portions, during each of which the output signal rises along a first path from a first voltage value to a second voltage value, and second portions, during each of which the output signal falls along a second path from said second value to said first value, at least one of said paths being nonlinear; means for comparing said output of said oscillator means with said input voltage; and means for supplying a waveform representative of selected portions of the output of said comparing means to the output of said apparatus.
Claim 3
Dependent Claim
50 words
The apparatus of claim 1 wherein said supplying means supplies a waveform representative of the output of said comparing means only during one of said portions of each oscillation of said oscillator output, said one of said portions being a portion during which said output varies in a nonlinear manner.
Claim 4
Dependent Claim
36 words
The apparatus of claim 1 wherein the magnitude of the difference between said first voltage level and said second voltage level is greater than 50% of the magnitude of the supply voltage to said oscillator means.
Claim 5
Dependent Claim
125 words
Pulse width modulator apparatus for providing a waveform responsive to an input voltage, said apparatus comprising a quad comparator integrated circuit wherein: a first comparator is embodied as an oscillator for generating an output signal, said signal having alternate first portions, during each of which the output signal rises along a first path from a first voltage value to a second voltage value, and second portions, during each of which the output signal falls along a second path from said second value to said first value, at least one of said paths being nonlinear; a second comparator compares the output of said first comparator with said input voltage; and a third comparator, connected from the output of said second comparator, limits the maximum duty cycle.
Claim 6
Dependent Claim
125 words
Pulse width modulator apparatus for providing a waveform responsive to an input voltage, said apparatus comprising a quad comparator integrated circuit wherein: a first comparator is embodied as an oscillator for generating an output signal, said signal having alternate first portions, during each of which the output signal rises along a first path from a first voltage value to a second voltage value, and second portions, during each of which the output signal falls along a second path from said second value to said first value, at least one of said paths being nonlinear; a second comparator compares the output of said first comparator with said input voltage; and a third comparator, connected from the output of said second comparator, limits the maximum duty cycle.
Claim 7
Dependent Claim
20 words
The apparatus of claim 4 wherein a fourth comparator, connected to the output of said third comparator performs current limiting.
Claim 8
Dependent Claim
14 words
The apparatus of claim 1 wherein each said nonlinear path is an exponential curve.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-29 | 1989-01-28 | 1989-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-29 | 1993-01-28 | 1993-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-29 | 1997-01-28 | 1997-07-30 | $7700.00 | Window Closed / Lapsed |