US6323610B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silent spin sine wave generator
Assignee: Texas Instruments Inc
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Filing: 2000-07-25
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Granted: 2001-11-27
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Expires: 2020-07-25
Abstract
Abstract A method and circuit are presented for operating a polyphase dc motor in which drive voltages are applied to the windings of the motor in predetermined phases. Zero crossings of currents flowing in respective windings of the motor are detected, and phases of the drive voltages are adjusted to have zero crossings substantially simultaneously with the detected zero crossings of the currents flowing in respective windings of the motor. The method includes generating a set of three waveforms ( 45,46,47 ) to provide drive voltages to respective windings of the motor. Each waveform has a period of 360° with a first segment ( 43 ) having a value of zero for 120°, followed by a second segment ( 50 ) having an “up slope” shape for 60°, followed by a third segment ( 67,68 ) having two consecutive “cap” shapes for 120°, followed by a fourth segment ( 52 ) having “down slope” shape for 60°. Each waveform of said set is displaced from one another by 120°. As a result, the acoustic motor noise is reduced.
Inventors
- 👤 Vincent Ng
- 👤 Bert White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:27
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/10; H02P6/08; H02P6/14; H02P6/16; H02P6/18; H02P6/182
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
100 words
A method for operating a polyphase dc motor, comprising: generating a set of three waveforms to provide drive voltages to respective windings of the motor, each waveform having period of 360° with a first segment with a value of zero for 120°, followed by a second segment with an “up slope” shape for 60°, followed by a third segment with two consecutive “cap” shapes for 120°, followed by a fourth segment having “down slope” shape for 60°, each waveform of said set being displaced from one another by 120°; and applying said waveforms to said respective windings of the motor.
Claim 2
Independent Claim
100 words
A method for operating a polyphase dc motor, comprising: generating a set of three waveforms to provide drive voltages to respective windings of the motor, each waveform having period of 360° with a first segment with a value of zero for 120°, followed by a second segment with an “up slope” shape for 60°, followed by a third segment with two consecutive “cap” shapes for 120°, followed by a fourth segment having “down slope” shape for 60°, each waveform of said set being displaced from one another by 120°; and applying said waveforms to said respective windings of the motor.
Claim 3
Dependent Claim
20 words
The method of claim 1 further comprising pulse-width modulating the drive voltages prior to application thereof to said motor windings.
Claim 4
Dependent Claim
37 words
The method of claim 1 wherein said segments each approximate: VMAG(sin(ωt−φ)−min{sin(ωt), sin(ωt−120°), sin(ωt−240°)}, where VMAG is a maximum amplitude of each waveform, ωt is a phase angle of the waveform, and φ is an initial phase angle.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein each of said waveform segments comprises at least one linear waveform.
Claim 6
Dependent Claim
23 words
The method of claim 4 wherein each of said waveform segments has two linear portions, with a breakpoint at a midpoint section thereof.
Claim 7
Independent Claim
118 words
A method for reducing acoustic noise in operating a polyphase dc motor, comprising: generating a set of n waveforms to provide drive voltages to respective windings of the motor, wherein n is a number of phases of said polyphase dc motor; and wherein each waveform having period of 360° with a first segment with a value of zero for (360/n)°, followed by a second segment with an “up slope” shape for (360/2n)°, followed by a third segment with two consecutive “cap” shapes for (360/n)°, followed by a fourth segment having “down slope” shape for (360/2n)°, each waveform of said set being displaced from one another by (360/n)°; and applying said waveforms to said respective windings of the motor.
Claim 8
Independent Claim
118 words
A method for reducing acoustic noise in operating a polyphase dc motor, comprising: generating a set of n waveforms to provide drive voltages to respective windings of the motor, wherein n is a number of phases of said polyphase dc motor; and wherein each waveform having period of 360° with a first segment with a value of zero for (360/n)°, followed by a second segment with an “up slope” shape for (360/2n)°, followed by a third segment with two consecutive “cap” shapes for (360/n)°, followed by a fourth segment having “down slope” shape for (360/2n)°, each waveform of said set being displaced from one another by (360/n)°; and applying said waveforms to said respective windings of the motor.
Claim 9
Dependent Claim
19 words
The method of claim 6 further comprising pulse-width modulating said driving voltages prior to application thereof to said windings.
Claim 10
Dependent Claim
49 words
The method of claim 6 wherein said segments each approximate: VMAG(sin(ωt−φ)−min{sin(ωt−0×360/n)°, sin(ωt−1×360/n)°, . . . sin(ωt−(n−1)×360/n)°}), where VMAG is a maximum amplitude of each waveform, n is a number of phases of said motor, ωt is a phase angle of the waveform, and φ is an initial phase angle.
Claim 11
Dependent Claim
17 words
The method of claim 6 wherein each of said waveform segments comprises at least one linear waveform.
Claim 12
Dependent Claim
23 words
The method of claim 9 wherein each of said waveform segments has two linear portions, with a breakpoint at a midpoint section thereof.
Claim 13
Dependent Claim
90 words
A circuit for operating an n-phase dc motor, comprising: drivers for applying n driving signal waveforms to the motor; and a source of said driving signal waveforms, each having period of 360° with a first segment with a value of zero for (360/n)°, followed by a second segment with an “up slope” shape for (360/2n)°, followed by a third segment with two consecutive “cap” shapes for (360/n)°, followed by a fourth segment having “down slope” shape for (360/2n)°, each waveform of said set being displaced from one another by (360/n)°.
Claim 14
Dependent Claim
90 words
A circuit for operating an n-phase dc motor, comprising: drivers for applying n driving signal waveforms to the motor; and a source of said driving signal waveforms, each having period of 360° with a first segment with a value of zero for (360/n)°, followed by a second segment with an “up slope” shape for (360/2n)°, followed by a third segment with two consecutive “cap” shapes for (360/n)°, followed by a fourth segment having “down slope” shape for (360/2n)°, each waveform of said set being displaced from one another by (360/n)°.
Claim 15
Dependent Claim
35 words
The circuit of claim 11 wherein said source of driving signal waveforms is a first MDAC to generate said “up slope” and “down slope” waveforms, and a second MDAC to generate said “cap” shape waveforms.
Claim 16
Dependent Claim
14 words
The circuit of claim 12 wherein said driving signal waveforms comprise substantially linear segments.
Claim 17
Dependent Claim
21 words
The circuit of claim 13 wherein each of said waveforms has two linear portions, with a breakpoint at a midpoint thereof.
Claim 18
Dependent Claim
31 words
The circuit of claim 11 further comprising a multiplexer connected to receive outputs of said MDACs, said multiplexer being operated to selectively apply said outputs of said MDACs to said drivers.
Claim 19
Dependent Claim
22 words
The circuit of claim 11 further comprising a circuit for pulse-width modulating driving signal waveforms prior to application thereof to said drivers.
Claim 20
Dependent Claim
9 words
The circuit of claim 11 wherein n is 3.
Claim 21
Dependent Claim
40 words
The circuit of claim 11 wherein said segments each approximate: VMAG(sin(ωt−φ)−min{sin(ωt−0×360/n)°, sin(ωt−1×360/n)°, . . . sin(ωt−(n−1)×360/n)°}), where VMAG is a maximum amplitude of each waveform, ωt is a phase angle of the waveform, and φ is an initial phase angle.
Claim 22
Dependent Claim
115 words
A disk drive product of the type having a dc brushless, Hall-less, three phase motor for rotating a data containing media, comprising: three driver circuits for providing driving signals to selected respective sets of windings in the motor; a source of three motor drive voltage waveforms to provide said drive signals, each waveform having period of 360° with a first segment with a value of zero for 120°, followed by a second segment with an “up slope” shape for 60°, followed by a third segment with two consecutive “cap” shapes for 120°, followed by a fourth segment having “down slope” shape for 60°, each waveform of said set being displaced from one another by 120°.
Claim 23
Dependent Claim
115 words
A disk drive product of the type having a dc brushless, Hall-less, three phase motor for rotating a data containing media, comprising: three driver circuits for providing driving signals to selected respective sets of windings in the motor; a source of three motor drive voltage waveforms to provide said drive signals, each waveform having period of 360° with a first segment with a value of zero for 120°, followed by a second segment with an “up slope” shape for 60°, followed by a third segment with two consecutive “cap” shapes for 120°, followed by a fourth segment having “down slope” shape for 60°, each waveform of said set being displaced from one another by 120°.
Claim 24
Dependent Claim
35 words
The disk drive product of claim 19 wherein said driver circuits each comprise a pair of FETs connected together at a driving signal node and in series between a voltage supply and a reference potential.
Claim 25
Dependent Claim
32 words
The disk drive product of claim 19 further comprising a multiplexer connected to receive said motor drive voltage waveforms and to selectively apply said motor drive voltage waveforms to said driver circuits.
Claim 26
Dependent Claim
27 words
The disk drive product of claim 19 further comprising a circuit for pulse-width modulating the motor drive voltage waveforms prior to application thereof to said driver circuits.
Claim 27
Dependent Claim
15 words
The circuit of claim 19 wherein said driving signal voltage waveforms comprise substantially linear segments.
Claim 28
Dependent Claim
21 words
The circuit of claim 23 wherein each of said waveforms has two linear portions, with a breakpoint at a midpoint thereof.
Claim 29
Dependent Claim
40 words
The circuit of claim 24 wherein said segments each approximate: VMAG(sin(ωt−φ)−min{sin(ωt−0×360/n)°, sin(ωt−1×360/n)°, . . . sin(ωt−(n−1)×360/n)°}), where VMAG is a maximum amplitude of each waveform, ωt is a phase angle of the waveform, and φ is an initial phase angle.
Claim 30
Dependent Claim
21 words
The disk drive product of claim 19 wherein said data containing media is a magnetic media of a hard disk drive.
References Cited (Backward Citations)
US6242883B1
Cited
US6121736A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-11-26 | 2005-05-28 | 2005-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-11-26 | 2009-05-28 | 2009-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-11-26 | 2013-05-28 | 2013-11-27 | $7700.00 | Window Closed / Lapsed |