US4554499A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Computer controlled motor
Assignee: Genentech Inc
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Filing: 1984-10-24
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Granted: 1985-11-19
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Expires: 2004-10-24
Abstract
Abstract To control a motor, a pulse width modulated signal from a computer is fed to a capacitor which stores each pulse as a voltage proportional to the width of the pulse, the capacitor being reset to zero by a leading edge reset circuit. The voltage on the capacitor is sampled by a sample/hold circuit the output of which is fed to a converter which converts the voltage signal to a frequency signal exponentially related to the voltage, and hence to the pulse width. The converter then powers a driver which drives the motor. The exponential relationship between the pulses and the signal fed to the motor permits a large variationin the frequency signal based on a small variation in pulse width and hence permits accurate control of the motor.
Inventors
- 👤 Leonard H. Sherman
- 👤 James R. Swartz
- 👤 James M. Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:54
CPC Classifications
G; G05; G05D; G05D7/00; G05D7/06; G05D7/0617; G05D7/0629; G05D7/0676; H; H02; H02P; H02P7/00; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0324; Y10T137/0329
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
91 words
Apparatus for driving a motor at a desired motor speed, said apparatus comprising: means for generating a command signal having a preselected pulse width which varies logarithmically with said desired motor speed; means connected to receive said command signal for generating a control signal which has a preselected control component exponentially related to said command component of said command signal; means connected to receive said control signal and for translating the control signal into said desired motor speed, which speed is directly proportional to said control component of said control signal.
Claim 2
Dependent Claim
91 words
Apparatus for driving a motor at a desired motor speed, said apparatus comprising: means for generating a command signal having a preselected pulse width which varies logarithmically with said desired motor speed; means connected to receive said command signal for generating a control signal which has a preselected control component exponentially related to said command component of said command signal; means connected to receive said control signal and for translating the control signal into said desired motor speed, which speed is directly proportional to said control component of said control signal.
Claim 3
Dependent Claim
142 words
Apparatus for driving a motor at a desired motor speed, said apparatus comprising: means for generating a command signal having a preselected pulse width which varies logarithmically with said desired motor speed; means connected to receive said command signal for generating a control signal which has a preselected control component exponentially related to said command component of said command signal; means connected to receive said control signal and for translating the control signal into said desired motor speed, which speed is directly proportional to said control component of said control signal; said means connected to receive said command signal including a charge storage means for accumulating voltage, a source means for supplying voltage to said charge storage means as a function of said component of said command signal and a means for sampling the voltage so accumulated on said charge storage means.
Claim 4
Dependent Claim
142 words
Apparatus for driving a motor at a desired motor speed, said apparatus comprising: means for generating a command signal having a preselected pulse width which varies logarithmically with said desired motor speed; means connected to receive said command signal for generating a control signal which has a preselected control component exponentially related to said command component of said command signal; means connected to receive said control signal and for translating the control signal into said desired motor speed, which speed is directly proportional to said control component of said control signal; said means connected to receive said command signal including a charge storage means for accumulating voltage, a source means for supplying voltage to said charge storage means as a function of said component of said command signal and a means for sampling the voltage so accumulated on said charge storage means.
Claim 5
Dependent Claim
118 words
Apparatus for driving a motor at a desired motor speed, said apparatus comprising: means for generating a command signal having a preselected pulse width which varies logarithmically with said desired motor speed; means connected to receive said command signal for generating a control signal which has a preselected control component exponentially related to said command component of said command signal; means connected to receive said control signal and for translating the control signal into said desired motor speed, which speed is directly proportional to said control component of said control signal; circuit means for sensing said component of said command signal and for shutting off the motor when said component of said command signal reaches a predetermined limit.
Claim 6
Dependent Claim
118 words
Apparatus for driving a motor at a desired motor speed, said apparatus comprising: means for generating a command signal having a preselected pulse width which varies logarithmically with said desired motor speed; means connected to receive said command signal for generating a control signal which has a preselected control component exponentially related to said command component of said command signal; means connected to receive said control signal and for translating the control signal into said desired motor speed, which speed is directly proportional to said control component of said control signal; circuit means for sensing said component of said command signal and for shutting off the motor when said component of said command signal reaches a predetermined limit.
Claim 7
Dependent Claim
30 words
An apparatus as set forth in claim 2, wherein said means connected to receive said command signal further includes means for sampling said voltage stored on said charge accumulating means.
Claim 8
Dependent Claim
29 words
An apparatus as set forth in claim 3, wherein said circuit means includes a comparator which changes state when said characteristic of said command signal exceeds said predetermined limit.
Claim 9
Dependent Claim
37 words
An apparatus as set forth in claim 5, wherein said circuit means further includes means for locking the output of said comparator in a first state when said component of said command signal exceeds said predetermined limit.
Claim 10
Dependent Claim
35 words
An apparatus as set forth in claim 6, wherein said circuit means includes a gating means which cuts off operating power to the motor when the output of said comparator is in said first state.
Claim 11
Dependent Claim
56 words
Apparatus as set forth in claim 1, wherein said means connected to receive said command signal includes a charge storage means for accumulating voltage, a source means for supplying voltage to said charge storage means as a function of said pulse width and a means for sampling the voltage so accumulated on said charge storage means.
Claim 12
Dependent Claim
37 words
An apparatus as set forth in claim 1, further including circuit means for sensing said component of said command signal and for shutting off the motor when said component of said command signal reaches a predetermined limit.
Claim 13
Independent Claim
90 words
An apparatus for supplying a controlled amount nutrients to cell cultures, comprising: a pump driven by a motor for supplying nutrients to cell culture; means for applying a control signal to said motor, said control signal having a preselected control component directly proportional to the speed of said motor whereby nutrients are supplied in controlled amounts to said cell culture; means for generating said control signal in response to a command signal having a preselected command component which is a logarithmic function of said control component of said control signal.
Claim 14
Independent Claim
90 words
An apparatus for supplying a controlled amount nutrients to cell cultures, comprising: a pump driven by a motor for supplying nutrients to cell culture; means for applying a control signal to said motor, said control signal having a preselected control component directly proportional to the speed of said motor whereby nutrients are supplied in controlled amounts to said cell culture; means for generating said control signal in response to a command signal having a preselected command component which is a logarithmic function of said control component of said control signal.
Claim 15
Dependent Claim
20 words
The apparatus of claim 10 wherein the motor is a stepping motor and the control signal is pulsed direct current.
Claim 16
Dependent Claim
17 words
The apparatus of claim 10 which includes a means for converting the command signal into a voltage.
Claim 17
Dependent Claim
24 words
The apparatus of claim 12 which includes a means for converting the voltage into a frequency which is an exponential function of the voltage.
Claim 18
Independent Claim
71 words
A method for governing the operation of a motor to achieve a desired motor speed, said method comprising the steps of: generating a command signal having a pulse width logarithmically related to said desired motor speed; converting said command signal into a control signal having a frequency exponentially related to said component of said command signal; and driving said motor at a speed proportional to the frequency of the control signal.
Claim 19
Independent Claim
71 words
A method for governing the operation of a motor to achieve a desired motor speed, said method comprising the steps of: generating a command signal having a pulse width logarithmically related to said desired motor speed; converting said command signal into a control signal having a frequency exponentially related to said component of said command signal; and driving said motor at a speed proportional to the frequency of the control signal.
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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) | 1988-11-18 | 1989-05-20 | 1989-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-18 | 1993-05-20 | 1993-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-18 | 1997-05-20 | 1997-11-19 | $7700.00 | Window Closed / Lapsed |