Patent US4538100A successfully refreshed from Google Patents.
US4538100A
Expired / Lapsed
US
⏱️ 0.0 years remaining
DC to AC inverter and motor control system
Assignee: Creative Technology Inc
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Filing: 1980-03-10
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Granted: 1985-08-27
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Expires: 2000-03-10
Abstract
Abstract This relates to a low cost reliable controller which may be used in conjunction with induction motors or, more generally, to generate AC power from a DC source. The system utilizes a microprocessor in combination with low cost parallel transistors to provide the control function. A feedback module monitors the actual rotor speed and conveys this information back to the microprocessor. A voltage boost module may be used in combination with the microprocessor and switching circuits to optimize the overall efficiency of the system. The microprocessor computes slip and controls the voltage drive in order to further optimize efficiency of the system as a function of motor speed. Both the footfeed voltage and boosted voltage are analog voltages and are applied to an A/D converter. The output of the A/D converter presents a digital representation of the footfeed voltage or boost voltage to the microprocessor.
Inventors
- 👤 William J. Tuten
- 👤 Kennith D. Crosby
- 👤 Bertil R. Bergquist
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:56
CPC Classifications
H; H02; H02P; H02P23/00; H02P23/06; H02P23/07; B; B60; B60L; B60L50/00; B60L50/50; B60L50/51; B60L2220/00; B60L2220/10; B60L2220/30; Y; Y02; Y02T; Y02T10/00; Y02T10/60; Y02T10/64; Y02T10/70
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
117 words
A DC to AC inverter system, comprising: microprocessing means; a first plurality of counting means each coupled to said microprocessing means for receiving data therefrom and for generating a plurality of square wave signals; a second plurality of driver means, each one of which is coupled to a different one of said first plurality of counting means for receiving the square wave signals generated thereby and deriving therefrom one phase of a multiphase AC signal; and first means coupled to said microprocessor means for varying the frequency of each phase of said multiphase signal by varying the contents of each of said first plurality of counting means associated with each of said second plurality of driver means.
Claim 2
Dependent Claim
117 words
A DC to AC inverter system, comprising: microprocessing means; a first plurality of counting means each coupled to said microprocessing means for receiving data therefrom and for generating a plurality of square wave signals; a second plurality of driver means, each one of which is coupled to a different one of said first plurality of counting means for receiving the square wave signals generated thereby and deriving therefrom one phase of a multiphase AC signal; and first means coupled to said microprocessor means for varying the frequency of each phase of said multiphase signal by varying the contents of each of said first plurality of counting means associated with each of said second plurality of driver means.
Claim 3
Dependent Claim
19 words
A system according to claim 1 wherein three of said counting means are employed to generate three-phase AC power.
Claim 4
Dependent Claim
47 words
A system according to claim 1 wherein said microprocessing means comprises: a microprocessor; memory means coupled to said microprocessor; and address selection means coupled to said microprocessor, said memory means and said plurality of counting means for accessing said memory means and said plurality of counting means.
Claim 5
Dependent Claim
20 words
A system according to claim 3 wherein said memory means includes a random access memory and a programmable read-only memory.
Claim 6
Dependent Claim
39 words
A system according to claim 3 further including a variable voltage boost means coupled to said microprocessing means and to said driver means and controlled by said microprocessing means for supplying a variable boost voltage to said driver means.
Claim 7
Dependent Claim
19 words
A system according to claim 5 wherein said boost means is equipped with regeneration means for dissipating excess current.
Claim 8
Dependent Claim
21 words
A system according to claim 6 wherein said boost means provides both positive and negative boost voltages to said driver means.
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) | 1988-08-26 | 1989-02-25 | 1989-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-26 | 1993-02-25 | 1993-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-26 | 1997-02-25 | 1997-08-27 | $7700.00 | Window Closed / Lapsed |