US3748559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speed control arrangement for dc motors
Assignee: Robert Bosch GmbH
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Filing: 1972-01-31
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Granted: 1973-07-24
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Expires: 1992-01-31
Abstract
Abstract An arrangement for controlling the speeds of DC motors, in which a first transistor is connected in series with the motor and supplies current for driving the motor. The operational state of the first transistor is controlled by a second complementary transistor. An adjustable resistor sets the base current for the second controlling transistor. The two transistors form a switching circuit in conjunction with a feedback resistor, so that switching takes place as a function of the voltage appearing across a capacitor connected in parallel with the motor. Inductance between the motor and the first transistor functions together with the capacitor as a smoothing circuit.
Inventors
- 👤 H Steinmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:16
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/29; H02P7/291
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
289 words
An arrangement, comprising in combination a D.C. motor having two motor terminals; a source of electrical energy for said motor; and astable circuit means having two states and operative in one state for connecting said source to said motor to effect the flow of electrical energy from said source into said motor, and operative in the other state for disconnecting said source from said motor to terminate the flow of electrical energy from said source into said motor, said astable circuit means comprising an electronic switch connected to said motor for conducting motor current, a timing capacitor connected across said motor terminals, and charging-discharging circuit means connecting said timing capacitor to said electronic switch in such a manner as to alternately render said switch conductive and non-conductive in dependence upon the voltage across said capacitor, and thereby in dependence upon the energy stored in said capacitor, said charging-discharging circuit means being operative when said switch conducts for causing said capacitor to undergo a first change of stored energy whose duration controls the length of time said switch conducts, and operative when said switch does not conduct for causing said capacitor to undergo a second change of stored energy whose duration controls the length of time said switch does not conduct and during which energy stored in said capacitor flows into said motor, whereby said capacitor serves both for smoothing motor operation and also for timing the relative durations of said two states of said astable circuit means, said charging-discharging circuit means further including varying means for selectably varying the relative durations of said two states of said astable circuit means by varying the duration of at least one of said changes of stored energy, to thereby vary motor speed.
Claim 2
Dependent Claim
289 words
An arrangement, comprising in combination a D.C. motor having two motor terminals; a source of electrical energy for said motor; and astable circuit means having two states and operative in one state for connecting said source to said motor to effect the flow of electrical energy from said source into said motor, and operative in the other state for disconnecting said source from said motor to terminate the flow of electrical energy from said source into said motor, said astable circuit means comprising an electronic switch connected to said motor for conducting motor current, a timing capacitor connected across said motor terminals, and charging-discharging circuit means connecting said timing capacitor to said electronic switch in such a manner as to alternately render said switch conductive and non-conductive in dependence upon the voltage across said capacitor, and thereby in dependence upon the energy stored in said capacitor, said charging-discharging circuit means being operative when said switch conducts for causing said capacitor to undergo a first change of stored energy whose duration controls the length of time said switch conducts, and operative when said switch does not conduct for causing said capacitor to undergo a second change of stored energy whose duration controls the length of time said switch does not conduct and during which energy stored in said capacitor flows into said motor, whereby said capacitor serves both for smoothing motor operation and also for timing the relative durations of said two states of said astable circuit means, said charging-discharging circuit means further including varying means for selectably varying the relative durations of said two states of said astable circuit means by varying the duration of at least one of said changes of stored energy, to thereby vary motor speed.
Claim 3
Dependent Claim
14 words
An arrangement as defined in claim 1, wherein said electronic switch is a transistor.
Claim 4
Dependent Claim
26 words
An arrangement as defined in claim 1, and further including a smoothing inductor connected in series with said motor aNd in series with said electronic switch.
Claim 5
Dependent Claim
16 words
An arrangement as defined in claim 1, wherein said motor is a series D. C. motor.
Claim 6
Dependent Claim
72 words
An arrangement as defined in claim 1, wherein said electronic switch comprises a first transistor having a control electrode, an output electrode and a reference electrode, and wherein said charging-discharging circuit means comprises a second transistor having a control electrode, an output electrode and a reference electrode, with said second transistor being so connected to said first transistor that the conductivity of said second transistor controls the conductivity of said first transistor.
Claim 7
Dependent Claim
44 words
An arrangement as defined in claim 5, wherein the output electrode of said first transistor is connected to the control electrode of said second transistor, and wherein the output electrode of said second transistor is connected to the control electrode of said first transistor.
Claim 8
Dependent Claim
18 words
An arrangement as defined in claim 6, wherein said first and second transistors are of opposite conductivity type.
Claim 9
Dependent Claim
25 words
An arrangement as defined in claim 7, wherein said varying means comprising adjustable resistor means operative for varying the biasing voltage of said second transistor.
Claim 10
Dependent Claim
52 words
An arrangement as defined in claim 7, wherein said varying means comprises a potentiometer whose movable tap is connected to the control electrode of said control electrode of said second transistor, and wherein said timing capacitor is connected between the output electrode of said second transistor and one terminal of said source.
Claim 11
Dependent Claim
48 words
An arrangement as defined in claim 6, wherein the output electrode of said second transistor is connected directly to the control electrode of said first transistor, and further wherein a feedback resistor connects the output electrode of said first transistor to the control electrode of said second transistor.
Claim 12
Dependent Claim
50 words
An arrangement as defined in claim 10, and further including a smoothing inductor connected between one terminal of said motor and the output electrode of said first transistor, with the refernece electrode of said second transistor being connected to the junction of said one motor terminal and said smoothing inductor.
Claim 13
Dependent Claim
33 words
An arrangement as defined in claim 11, and further including a diode connected between the reference electrode of said second transistor and the junction of said smoothing inductor and said one motor terminal.
Claim 14
Dependent Claim
164 words
An arrangement for controlling the speed of the DC motor, comprising, in combination, DC motor means; first transistor means connected to said motor means and conducting current for driving said motor means at a predetermined speed; second transistor means connected to said first transistor means for controlling the operational state of said first transistor means; adjustable resistor means connected to said second transistor means for adjusting the base current of said second transistor means; capacitor means connected in parallel with said motor means; inductance means connected in series with said motor means; and feedback resistor means connected between said first transistor means and said second transistor means, said transistor means and said resistor means comprising switching means switchable dependent on the voltage across said capacitor means, and wherein said adjustable resistor means comprises a potentiometer with movable contacts connected to the base of said second transistor means, and further including means for connecting said capacitor means to the emitter of said second transistor means.
Claim 15
Dependent Claim
164 words
An arrangement for controlling the speed of the DC motor, comprising, in combination, DC motor means; first transistor means connected to said motor means and conducting current for driving said motor means at a predetermined speed; second transistor means connected to said first transistor means for controlling the operational state of said first transistor means; adjustable resistor means connected to said second transistor means for adjusting the base current of said second transistor means; capacitor means connected in parallel with said motor means; inductance means connected in series with said motor means; and feedback resistor means connected between said first transistor means and said second transistor means, said transistor means and said resistor means comprising switching means switchable dependent on the voltage across said capacitor means, and wherein said adjustable resistor means comprises a potentiometer with movable contacts connected to the base of said second transistor means, and further including means for connecting said capacitor means to the emitter of said second transistor means.
Claim 16
Dependent Claim
168 words
An arrangement for controlling the speed of the DC motor, comprising, in combination, DC motor means; first transistor means connected to said motor means and conducting current for driving said motor means at a predetermined speed; second transistor means connected to said first transistor means for controlling the operational state of said first transistor means; adjustable resistor means connected to said second transistor means for adjusting the base currenT of said second transistor means; capacitor means connected in parallel with said motor means; inductance means connected in series with said motor means; and feedback resistor means connected between said first transistor means and said second transistor means, said transistor means and said resistor means comprising switching means switchable dependent on the voltage across said capacitor means, and wherein said inductance means is connected between one terminal of said motor means and the collector of said first transistor means, the emitter of said second transistor means being connected to the junction of said motor means and said inductance means.
Claim 17
Dependent Claim
168 words
An arrangement for controlling the speed of the DC motor, comprising, in combination, DC motor means; first transistor means connected to said motor means and conducting current for driving said motor means at a predetermined speed; second transistor means connected to said first transistor means for controlling the operational state of said first transistor means; adjustable resistor means connected to said second transistor means for adjusting the base currenT of said second transistor means; capacitor means connected in parallel with said motor means; inductance means connected in series with said motor means; and feedback resistor means connected between said first transistor means and said second transistor means, said transistor means and said resistor means comprising switching means switchable dependent on the voltage across said capacitor means, and wherein said inductance means is connected between one terminal of said motor means and the collector of said first transistor means, the emitter of said second transistor means being connected to the junction of said motor means and said inductance means.
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) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |