US3766497A
Expired / Lapsed
US
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Method and apparatus for pulse width modulation with variable frequency modes
Assignee: POWER CONTROL CORP
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Filing: 1972-01-21
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Granted: 1973-10-16
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Expires: 1992-01-21
Abstract
Abstract The number of pulses modulated during each period of the input frequency to a pulse width modulator is controlled to be a multiple of the input frequency, where the multiple is changed as predetermined frequency range boundaries are crossed. The frequency multiple is increased inversely with the frequency range so that, at lower frequency ranges a greater number of pulses are modulated during each period. Unstable frequency multiple switching is prevented at the frequency range boundary crossover by defining each boundary as two crossover limits where one limit is at a frequency slightly higher than the boundary and the other limit is at a frequency slightly lower than the boundary. Decreasing frequency (increasing period) then crosses a first limit at a frequency slightly lower (longer period) than the boundary and increasing frequency (decreasing period) crosses a second limit at a frequency slightly higher (shorter period) than the boundary.
Inventors
- 👤 K Opal
- 👤 W Ley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:36
CPC Classifications
H; H02; H02P; H02P27/00; H02P27/04; H02P27/06; H02P27/08; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/525; H02M7/527; H03; H03K; H03K7/00; H03K7/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
115 words
A method of pulse width modulation wherein the modulated output pulse frequency is at a variable multiple of input frequency comprising: periodically sampling a representation of input frequency to produce sample code signals representing different frequency ranges; translating the sample code signals into a corresponding plurality of frequency gate control signals, one for each frequency range; generating a pulse series for each of the frequency ranges as a multiple of the input frequency where the multiple increases for successively lower frequency ranges; generating a series of gating pulses corresponding to that pulse series whose multiple is selected by said frequency gate control signals, and driving a pulse width modulator with said series of gating pulses.
Claim 2
Independent Claim
115 words
A method of pulse width modulation wherein the modulated output pulse frequency is at a variable multiple of input frequency comprising: periodically sampling a representation of input frequency to produce sample code signals representing different frequency ranges; translating the sample code signals into a corresponding plurality of frequency gate control signals, one for each frequency range; generating a pulse series for each of the frequency ranges as a multiple of the input frequency where the multiple increases for successively lower frequency ranges; generating a series of gating pulses corresponding to that pulse series whose multiple is selected by said frequency gate control signals, and driving a pulse width modulator with said series of gating pulses.
Claim 3
Dependent Claim
136 words
In a pulse width modulator, the combination of first means for generating a plurality of pulse series where the pulse rate in each series is a predetermined multiple of the frequency of an input signal applied to the modulator, and each pulse series corresponds to a respective one of a plurality of frequency ranges; second means for periodically sampling a representation of the input frequency to the modulator to produce a sample code signal set identifying the frequency range; third means for producing a series of gate pulses having a pulse rate during a period corresponding to the code signal set sampled during the previous period; and fourth means responsive to said gate pulses and said code signal set and to a representation of output voltage from the modulator for producing pulse width modulation output signals.
Claim 4
Dependent Claim
136 words
In a pulse width modulator, the combination of first means for generating a plurality of pulse series where the pulse rate in each series is a predetermined multiple of the frequency of an input signal applied to the modulator, and each pulse series corresponds to a respective one of a plurality of frequency ranges; second means for periodically sampling a representation of the input frequency to the modulator to produce a sample code signal set identifying the frequency range; third means for producing a series of gate pulses having a pulse rate during a period corresponding to the code signal set sampled during the previous period; and fourth means responsive to said gate pulses and said code signal set and to a representation of output voltage from the modulator for producing pulse width modulation output signals.
Claim 5
Independent Claim
81 words
The method of pulse width modulation comprising generating control code signals representing each of a plurality of frequency ranges of an input signal, producing a pulse chain for each frequency range with a multiple number of pulses therein corresponding to the range, the pulse rate in each chain being inversely related to the maximum frequency of the associated range, and driving a pulse width modulator with gating pulse selected to correspond to the pulse chain gated by said control code signals.
Claim 6
Independent Claim
81 words
The method of pulse width modulation comprising generating control code signals representing each of a plurality of frequency ranges of an input signal, producing a pulse chain for each frequency range with a multiple number of pulses therein corresponding to the range, the pulse rate in each chain being inversely related to the maximum frequency of the associated range, and driving a pulse width modulator with gating pulse selected to correspond to the pulse chain gated by said control code signals.
Claim 7
Independent Claim
92 words
The method of pulse width modulation wherein the modulated output pulse frequency is a variable multiple of input frequency, comprising driving a pulse width modulator with a series of gating pulses which determine the number of pulses to be modulated during a predetermined period of the input frequency, sampling the frequency range of the input frequency during each period of the input frequency, and controlling the number of pulses to be modulated during each period of the input frequency as a switching function of the frequency range sampled during a previous period.
Claim 8
Independent Claim
92 words
The method of pulse width modulation wherein the modulated output pulse frequency is a variable multiple of input frequency, comprising driving a pulse width modulator with a series of gating pulses which determine the number of pulses to be modulated during a predetermined period of the input frequency, sampling the frequency range of the input frequency during each period of the input frequency, and controlling the number of pulses to be modulated during each period of the input frequency as a switching function of the frequency range sampled during a previous period.
Claim 9
Dependent Claim
194 words
In a pulse width modulator adapted to produce output pulses which vary over a predetermined frequency range regardless of the frequency of input signals applied to the modulator; the combination of means for Generating a plurality of pulse trains wherein the pulse rate in each train is a predetermined multiple of the frequency of said input signal applied to the modulator and each pulse train is representative of a respective one of a plurality of frequency ranges of said input signal; second means for periodically sampling a representation of the input frequency to the modulator to produce a digital signal identifying the frequency range of the input signal applied to the modulator; third means coupled to said second means and responsive to said digital signal for producing a series of gate pulses having a pulse rate which varies as a function of the numerical value of said digital signal; and fourth means responsive to said gate pulses, to said digital signal and to a representation of output voltage from the modulator for producing pulse width modulated output signals which vary over a predetermined fixed frequency range regardless of the frequency of said input signal.
Claim 10
Dependent Claim
194 words
In a pulse width modulator adapted to produce output pulses which vary over a predetermined frequency range regardless of the frequency of input signals applied to the modulator; the combination of means for Generating a plurality of pulse trains wherein the pulse rate in each train is a predetermined multiple of the frequency of said input signal applied to the modulator and each pulse train is representative of a respective one of a plurality of frequency ranges of said input signal; second means for periodically sampling a representation of the input frequency to the modulator to produce a digital signal identifying the frequency range of the input signal applied to the modulator; third means coupled to said second means and responsive to said digital signal for producing a series of gate pulses having a pulse rate which varies as a function of the numerical value of said digital signal; and fourth means responsive to said gate pulses, to said digital signal and to a representation of output voltage from the modulator for producing pulse width modulated output signals which vary over a predetermined fixed frequency range regardless of the frequency of said input signal.
References Cited (Backward Citations)
US3548342A
Cited
US3668560A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |