US3725758A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic feedback closed loop system for forward speed control and braking control
Assignee: United States Department of the Navy
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Filing: 1971-06-01
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Granted: 1973-04-03
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Expires: 1991-06-01
Abstract
Abstract This invention controls a dynamo-electric device, such as a DC motor for running at a desired operating speed. The motor speed is maintained at the desired level by feeding back a tachometer voltage indicative of the motor speed, to an adder whose output provides a positive polarity error signal. The error signal is amplified in two channels: an under speed channel and an over speed channel. The under speed channel provides a signal to a motor current control device which supplies the current to the motor to maintain the motor speed. An over speed signal is applied across a charged capacitor. The over speed signal being less than the voltage indicating the set speed charge on the capacitor, the capacitor discharges generating an over speed signal. This over speed signal is then applied to a braking control device which controls a mechanical brake.
Inventors
- 👤 V Loyk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:22
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/2855
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
239 words
A motor speed controller comprising: means to generate a predetermined signal amplitude level corresponding to a desired motor speed; means for generating a speed signal; means responsive to said predetermined signal and said speed signal to produce an output signal; means for applying a driving force to said motor when said output signal deviates from said predetermined amplitude level in a first direction; means responsive to said output signal for applying a braking force to the motor when said output signal amplitude deviates from said predetermined signal amplitude level in a second direction; wherein said deviating signals and said predetermined signal amplitude corresponding to the desired motor speed are of same polarity; said means for applying a braking force includes a capacitor means for storing said predetermined signal amplitude corresponding to said desired motor speed amplitude signal; a discharge path connected to said capacitor, said discharge path including a resistive means; a charging path connected between said capacitor means and said means to generate a predetermined signal; said capacitor means discharging through said resistive means in said discharge path to produce a braking signal when said motor increases in speed above said set speed, said braking signal being proportional to the difference between the predetermined signal level and the said signal deviation in the said first direction; and a braking means connected to said resistive means and responsive to said braking signal to control the speed of the motor.
Claim 2
Dependent Claim
239 words
A motor speed controller comprising: means to generate a predetermined signal amplitude level corresponding to a desired motor speed; means for generating a speed signal; means responsive to said predetermined signal and said speed signal to produce an output signal; means for applying a driving force to said motor when said output signal deviates from said predetermined amplitude level in a first direction; means responsive to said output signal for applying a braking force to the motor when said output signal amplitude deviates from said predetermined signal amplitude level in a second direction; wherein said deviating signals and said predetermined signal amplitude corresponding to the desired motor speed are of same polarity; said means for applying a braking force includes a capacitor means for storing said predetermined signal amplitude corresponding to said desired motor speed amplitude signal; a discharge path connected to said capacitor, said discharge path including a resistive means; a charging path connected between said capacitor means and said means to generate a predetermined signal; said capacitor means discharging through said resistive means in said discharge path to produce a braking signal when said motor increases in speed above said set speed, said braking signal being proportional to the difference between the predetermined signal level and the said signal deviation in the said first direction; and a braking means connected to said resistive means and responsive to said braking signal to control the speed of the motor.
Claim 3
Dependent Claim
50 words
The controller of claim 1, wherein: said means to generate a signal includes a positive voltage source and a negative voltage source; and said positive and said negative sources being connected to each other through a voltage divider network to produce said signal level corresponding to said desired motor speed.
Claim 4
Dependent Claim
96 words
The controller of claim 2, wherein: said means for generating a speed signal includes a tachometer connected to said voltage divider network and mechanically connected to said motor to produce a feedback signal corresponding to the actual motor speed; said tachometer signal combining with said sources across said divider network to produce a signal deviation in said second direction when said motor is in an overspeed condition; and said tachometer signal combining with said sources across said divider network for producing a signal deviation in said first direction when said motor is in an underspeed condition.
Claim 5
Dependent Claim
77 words
The controller of claim 3, wherein: said tachometer is connected to said positive source through a first pair of resistors, and said underspeed signal is generated at the common connection of said resistors; said tachometer being connected to said negative source by a second pair of resistances, and said overspeed signal is generated at the common connection of said resistors; and a third resistance, connected from said positive source to the common connection of said second pair.
Claim 6
Dependent Claim
33 words
The controller of claim 4, wherein said capacitor has first and second terminals; said first terminal is connected to said connections of said third resistor with said common connection of said second pair.
Claim 7
Dependent Claim
118 words
The controller of claim 5, wherein: said second terminal of said caPacitor is connected to said capacitor discharge and charging paths; said discharging path includes a first resistor connected to said capacitor and ground and said charging path includes a second resistor connected to said capacitor and ground; said second resistor having a lower resistance than said first resistance; said charging path including a diode inserted with said charging resistance permitting said capacitor to charge and preventing said capacitor from discharging; said discharging resistor having a diode connected in series for permitting said capacitor to discharge through said discharging resistance when said motor increases in speed above said desired speed producing a signal deviation in said first direction.
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |