US5202614A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-commutating, back-emf sensing, brushless dc motor controller
Assignee: Silicon Systems Inc
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Filing: 1989-09-25
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Granted: 1993-04-13
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Expires: 2009-09-25
Abstract
Abstract A method and apparatus to commutate the drive voltages of a brushless DC motor. The present invention determines rotor position and velocity by detecting the polarity reversal of the Back-EMF of an undriven leg when compared to a transformed pseudo-reference. In an extra measure of efficiency, the present invention is independent of hardware sensors; it includes a commutation delay timing circuit for optimization of motor operation, and it minimizes the participation of a microprocessor or other microcontroller.
Inventors
- 👤 David H. Peters
- 👤 Jeff Harth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:14
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/14; H02P6/16; H02P6/18; H02P6/182; H02P6/17
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
202 words
A circuit for commutating the voltage supply for a polyphase DC motor comprising: a commutation generator that receives as input a first signal and outputs a first binary word of a first number of binary digits; a commutation decoder that decodes said binary first word output of said commutation generator and generates a second binary word composed of a second number of bits; a motor driver which receives said second binary word and outputs a plurality of drive signals on a plurality of output lines, said plurality of output lines being connected to a plurality of terminals on a controlled motor; a transformation network attached to said plurality of output lines from said motor driver, said transformation network deriving a pseudo-reference voltage level from said plurality of output lines; a plurality of comparator circuits for comparing the voltage level on each of said output lines with said pseudo-reference voltage level and for providing as output a second signal dependent on the comparison of said levels; a logic circuit connected to the output of said plurality of comparators, said logic circuit deriving a third signal by combining said output of said plurality of comparators with said first binary word of said commutation generator;
Claim 2
Dependent Claim
202 words
A circuit for commutating the voltage supply for a polyphase DC motor comprising: a commutation generator that receives as input a first signal and outputs a first binary word of a first number of binary digits; a commutation decoder that decodes said binary first word output of said commutation generator and generates a second binary word composed of a second number of bits; a motor driver which receives said second binary word and outputs a plurality of drive signals on a plurality of output lines, said plurality of output lines being connected to a plurality of terminals on a controlled motor; a transformation network attached to said plurality of output lines from said motor driver, said transformation network deriving a pseudo-reference voltage level from said plurality of output lines; a plurality of comparator circuits for comparing the voltage level on each of said output lines with said pseudo-reference voltage level and for providing as output a second signal dependent on the comparison of said levels; a logic circuit connected to the output of said plurality of comparators, said logic circuit deriving a third signal by combining said output of said plurality of comparators with said first binary word of said commutation generator;
Claim 3
Dependent Claim
34 words
The circuit of claim 1, wherein said commutation generator further receives a first external signal, said first external signal used by said commutation generator to determine a proper form of said first binary word.
Claim 4
Dependent Claim
31 words
The circuit of claim 1 further including a filter, wherein said filter receives a second external signal, said second external signal used by said filter circuit to provide said first signal.
Claim 5
Dependent Claim
24 words
The circuit of claim 1, wherein said first signal is connected to a conversion means which converts said first signal to a fourth signal.
Claim 6
Dependent Claim
15 words
The circuit of claim 4, wherein said fourth signal is provided to an external controller.
Claim 7
Dependent Claim
32 words
The circuit of claim 1, wherein said commutation logic receives a third external signal, said third external signal used by said commutation logic to determine proper form of said second binary word.
Claim 8
Independent Claim
135 words
A method for controlling the commutation of the supply voltage of a DC motor comprising the steps of: cyclically counting a plurality of commutation states of said motor; advancing said counting on cue of a first signal; converting said counting into a set of voltages, said set appropriate for driving a DC motor through all or part of a revolution; monitoring a plurality of circuit points within said DC motor to produce a data set; transforming said data set from said plurality of circuit points into a second signal; comparing said data set with said signal, and deriving a third signal indicative of changing relative polarities of said data set with respect to said second signal; filtering said third signal to produce said first signal; driving said motor with one of said set of voltages.
Claim 9
Independent Claim
135 words
A method for controlling the commutation of the supply voltage of a DC motor comprising the steps of: cyclically counting a plurality of commutation states of said motor; advancing said counting on cue of a first signal; converting said counting into a set of voltages, said set appropriate for driving a DC motor through all or part of a revolution; monitoring a plurality of circuit points within said DC motor to produce a data set; transforming said data set from said plurality of circuit points into a second signal; comparing said data set with said signal, and deriving a third signal indicative of changing relative polarities of said data set with respect to said second signal; filtering said third signal to produce said first signal; driving said motor with one of said set of voltages.
Claim 10
Dependent Claim
17 words
The method of claim 7, wherein said counting takes place on a plurality of binary data lines.
Claim 11
Dependent Claim
39 words
The method of claim 7, wherein said converting of counting into a set of voltages creates said set with one value of a first polarity and one value of a second polarity, said set comprising at least three voltages.
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) | 1996-04-12 | 1996-10-12 | 1997-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-12 | 2000-10-12 | 2001-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-12 | 2004-10-12 | 2005-04-13 | $7700.00 | Window Closed / Lapsed |