US5208518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
DC-DC boost converter for spindle motor control
Assignee: Compaq Computer Holding Ltd
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Filing: 1991-11-15
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Granted: 1993-05-04
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Expires: 2011-11-15
Abstract
Abstract A process and a circuit control the rotational speed of a direct current motor. In particular, the motor may be used to drive magnetic or optical data carriers. The motor is fed with a motor current by a switching device for commutation wherein the motor current induces a magnetic flux which generates the motor torque. The process and circuit increase the motor voltage applied to the motor in the startup or braking phase to a value above the supply voltage. Further, the process and circuit reduce the motor voltage during the commutation phase so that commutation switching may occur in a reduced-current condition.
Inventors
- 👤 Hans Grapenthin
- 👤 Horst Haug
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:47
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/20; H; H02; H02P; H02P6/00; H02P6/20; H02P6/24
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
164 words
A circuit for controlling the rotational speed of a direct current motor comprising: means for producing a supply voltage; means for modifying the supply voltage; a motor bridge coupled to the means for modifying the supply voltage and being effective to provide a motor voltage to the motor; a commutation circuit responsive to motor position that is effective to control the motor voltage provided by the motor bridge, the motor voltage being a commutated form of the modified supply voltage; means for controlling the modified supply voltage, the means for controlling the modified supply voltage producing a control signal effective to control the means for modifying the supply voltage, the means for controlling the modified supply voltage being effective to raise the modified supply voltage to a voltage above the supply voltage during the startup phase and during the braking phase and being effective to lower the modified supply voltage to a voltage below the supply voltage in the region of each commutation phase.
Claim 2
Dependent Claim
164 words
A circuit for controlling the rotational speed of a direct current motor comprising: means for producing a supply voltage; means for modifying the supply voltage; a motor bridge coupled to the means for modifying the supply voltage and being effective to provide a motor voltage to the motor; a commutation circuit responsive to motor position that is effective to control the motor voltage provided by the motor bridge, the motor voltage being a commutated form of the modified supply voltage; means for controlling the modified supply voltage, the means for controlling the modified supply voltage producing a control signal effective to control the means for modifying the supply voltage, the means for controlling the modified supply voltage being effective to raise the modified supply voltage to a voltage above the supply voltage during the startup phase and during the braking phase and being effective to lower the modified supply voltage to a voltage below the supply voltage in the region of each commutation phase.
Claim 3
Dependent Claim
185 words
The circuit of claim 1 wherein the means for controlling the modified supply voltage comprises: a speed control circuit for producing a speed signal responsive to the speed of the motor; an adaptive motor voltage generator producing a subtraction signal responsive to the position of the motor, the subtraction signal being at a maximum when the motor is in the region of each commutation phase; a subtraction circuit having a positive input responsive to the speed signal, a negative input responsive to the subtraction signal, and a difference output, the difference output being in proportional relation to the speed signal minus the subtraction signal; and a pulse width modulator for producing the control signal responsive to the difference output of the subtraction circuit, the control signal being effective to raise the modified supply voltage to a voltage above the supply voltage at the starting and at the braking phases in response to the speed signal, and being effective to lower the modified supply voltage to a voltage lower than the supply voltage in the region of each commutation phase in response to the subtraction signal.
Claim 4
Dependent Claim
38 words
The circuit of claim 2 wherein the means for controlling the modified supply voltage is further effective to allow the motor bridge to switch the motor voltage during a substantially current-free condition to accomplish commutation of the motor.
Claim 5
Dependent Claim
89 words
A process for controlling the rotational speed of a direct current motor, which comprises: producing a motor voltage from a supply voltage; supplying the motor voltage to the motor; raising the motor voltage to a voltage above the supply voltage during the startup phase of the motor; raising the motor voltage to a voltage above the supply voltage during the braking phase of the motor; reducing the motor voltage in the region of each commutation phase, including commutation phase regions which coincide with a startup or a braking phase.
Claim 6
Dependent Claim
89 words
A process for controlling the rotational speed of a direct current motor, which comprises: producing a motor voltage from a supply voltage; supplying the motor voltage to the motor; raising the motor voltage to a voltage above the supply voltage during the startup phase of the motor; raising the motor voltage to a voltage above the supply voltage during the braking phase of the motor; reducing the motor voltage in the region of each commutation phase, including commutation phase regions which coincide with a startup or a braking phase.
Claim 7
Dependent Claim
22 words
The process of claim 4 further comprising switching the motor voltage during a substantially current-free condition to accomplish commutation of the motor.
Claim 8
Dependent Claim
25 words
The process of claim 5 wherein reducing the motor voltage in the region of each commutation phase comprises reducing the motor voltage to substantially zero.
Claim 9
Dependent Claim
43 words
The process of claim 4 wherein raising the motor voltage at the startup phase and raising the motor voltage at the braking phase comprise raising the motor voltage to a voltage which is two to three times as high as the supply voltage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-03 | 1996-11-02 | 1997-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-03 | 2000-11-02 | 2001-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-03 | 2004-11-02 | 2005-05-04 | $7700.00 | Window Closed / Lapsed |