US3568027A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor control circuit with symmetrical topology
Assignee: International Business Machines Corp
•
Filing: 1969-11-18
•
Granted: 1971-03-02
•
Expires: 1989-11-18
Abstract
Abstract The invention concerns a motor control circuit especially useful with small direct-current-type motors and featuring a symmetrical circuit topology that achieves motor regulation and temperature compensation in a simplified manner. The circuit includes an upper portion comprising a motor model section for establishing a reference voltage to determine the speed of the motor, a parallel circuit section including the motor itself, a lower section intended for detection of current changes in the motor section, and a difference amplifier interconnected with the motor model and motor sections for maintaining an essentially zero potential difference between these sections. The symmetrical layout achieves a highly accurate measure of control over motor speed once a nominal speed has been established. Due to the symmetrical configuration of the circuit, effects of temperature and humidity are essentially eliminated. Some provision is made for alternative ways of controlling the desired motor speed including a variable control for changing motor speed in a regular fashion throughout a desired range of speeds.
Inventors
- 👤 James L Bacon
- 👤 George W Cleave
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:37
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/288; H02P7/2885; Y; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/902; Y10S388/907; Y10S388/91; Y10S388/917; Y10S388/923; Y10S388/934
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
80 words
The circuit of claim 1, wherein: said first and second active elements and said control means comprise transistors with said motor means being connected in the collector path of said first transistor, said reference means being connected in the collector path of said second transistor; and wherein said control transistor has its base-to-emitter path interconnecting said first and second junction points and its collector connected to the bases of said first and second transistors for control of current flow therethrough.
Claim 2
Dependent Claim
66 words
The circuit of claim 1, wherein: said first circuit sections of said first and second circuit legs comprise a balanced arrangement with said motor connected in said first section of said first circuit leg and said reference means serving as a motor model in the first section of said second circuit leg; and wherein said first and second active elements serve as a current sensor arrangement.
Claim 3
Dependent Claim
44 words
The circuit of claim 1, wherein said first and second circuit legs include components selected so that the components in said second circuit leg have a resistive value that is a multiple of the resistive value of the components in said first circuit leg.
Claim 4
Dependent Claim
30 words
The circuit of claim 1, further comprising means in said circuit for controlling said circuit sections and particularly said active elements to achieve a rapid startup time upon initial activation.
Claim 5
Dependent Claim
73 words
The circuit of claim 1, wherein compensation is automatically provided for variations in temperature with the following arrangement said first sections of said first and second circuit legs comprise a series arrangement designated a first loop with said control means in series therewith, the arrangement being such that positive and negative potentials extant in said first loop are balanced one against the other during operation of said circuit to achieve automatic temperature compensation.
Claim 6
Dependent Claim
46 words
The circuit of claim 1, wherein provision is made for automatic temperature compensation with the following arrangement said first and second active elements comprise a series second loop having positive and negative potentials therein that are effectively balanced against one another to achieve automatic temperature compensation.
Claim 7
Dependent Claim
91 words
The circuit of claim 1, wherein: said first sections of said first and second circuit legs comprise a series arrangement designated a first loop with said control means in series therewith, the arrangement being such that positive and negative potentials extant in said first loop are balanced one against the other during operation of said circuit to achieve automatic temperature compensation; and said first and second active elements comprise a series second loop having positive and negative potentials therein that are effectively balanced against one another to achieve automatic temperature compensation.
Claim 8
Dependent Claim
36 words
The circuit of claim 1, further comprising an additional active circuit element in the first section of said second leg, said additional active circuit element having an associated reference element for maintaining an accurate reference potential.
Claim 9
Dependent Claim
21 words
The circuit of claim 9, wherein said additional circuit element comprises a transistor and said reference element comprises a Zener diode.
Claim 10
Dependent Claim
30 words
The circuit of claim 9, further comprising means in the first section of said second circuit leg for establishing a desired reference potential over a predetermined range of reference potentials.
Claim 11
Dependent Claim
39 words
The circuit of claim 9, further comprising means associated with said reference section of said circuit for establishing a plurality of predetermined reference potentials in order to thereby establish a motor speed at a desired plurality of speed settings.
Claim 12
Dependent Claim
28 words
The circuit of claim 12, further comprising potentiometer means associated with said selector means to establish a range of settings within each of said plurality of selected settings.
Claim 13
Dependent Claim
38 words
The circuit of claim 12, wherein one of said plurality of means moves through a range of movement in a real time fashion to vary the reference potential with the passage of time or with some other parameter.
Claim 14
Dependent Claim
27 words
The circuit of claim 14, wherein said real time potentiometer means is varied in a linear fashion with the passage of time or with some other parameter.
Claim 15
Dependent Claim
24 words
The circuit of claim 14, further comprising means associated with said real time potentiometer for establishing a hyperbolic variance in control of said circuit.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |