US3812410A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for regulating the speed of a direct current motor
Assignee: Buehler GmbH
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Filing: 1970-12-28
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Granted: 1974-05-21
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Expires: 1990-12-28
Abstract
Abstract The ratio between the two states of an astable multivibrator is varied in dependence on the difference between a reference voltage and the output of an alternating current generator driven by the motor, a speed of which is to be regulated. One output of the multivibrator is connected to control the conductivity of a power transistor that controls the flow of current to the motor.
Inventors
- 👤 G Schaub
- 👤 K Schramm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:37
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/29; H02P7/291; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/921
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
140 words
An arrangement for regulating the speed of a D.C. motor, comprising in combination speed-monitorIng means for generating an electrical monitoring signal whose magnitude is indicative of the actual speed of the motor; reference-signal means for furnishing an electrical reference signal whose magnitude is indicative of the desired speed of the motor; error-signal means for furnishing an electrical error signal whose magnitude corresponds to the magnitude difference between said monitoring signal and said reference signal; and astable multivibrator means having control input means connected to said error-signal means and operative for varying the ratio of the time duration of the two astable states of said multivibrator means as a function of the magnitude of said error signal; and source means for furnishing current to the motor when said multivibrator means is in a predetermined one of said two astable states thereof.
Claim 2
Dependent Claim
140 words
An arrangement for regulating the speed of a D.C. motor, comprising in combination speed-monitorIng means for generating an electrical monitoring signal whose magnitude is indicative of the actual speed of the motor; reference-signal means for furnishing an electrical reference signal whose magnitude is indicative of the desired speed of the motor; error-signal means for furnishing an electrical error signal whose magnitude corresponds to the magnitude difference between said monitoring signal and said reference signal; and astable multivibrator means having control input means connected to said error-signal means and operative for varying the ratio of the time duration of the two astable states of said multivibrator means as a function of the magnitude of said error signal; and source means for furnishing current to the motor when said multivibrator means is in a predetermined one of said two astable states thereof.
Claim 3
Dependent Claim
43 words
An arrangement as defined in claim 1, wherein said monitoring means comprises a tachometer generator mechanically coupled to the motor, and wherein the frequency of said astable multivibrator means is at least several times greater than the rotational speed of said tachometer generator.
Claim 4
Dependent Claim
120 words
An arrangement as defined in claim 1, wherein said control input means of said multivibrator means comprises two electrical inputs each operative for receiving signals for varying the time duration of a respective one of said two states of said multivibrator means, and wherein said source means comprises a D.C. voltage source, and wherein said error-signal means comprises a control transistor having an emitter-collector path connected across said voltage source and having an emitter connected to one of said inputs and a collector connected to the other of said inputs, and a base, and wherein said error-signal means also includes means for applying to said base a voltage corresponding to the difference between said monitoring signal and said reference signal.
Claim 5
Dependent Claim
60 words
An arrangement as defined in claim 3, wherein said error-signal means includes an amplifying and rectifying transistor stage including a transistor whose collector is connected to said base of said control transistor and whose base is connected via a Zener diode to the output of said monitoring means and also via a resistor to the output of said reference-signal means.
Claim 6
Dependent Claim
31 words
An arrangement as defined in claim 4, wherein said reference-signal means comprises a voltage divider connected across said voltage source and having a tap constituting the output of said reference-signal means.
Claim 7
Dependent Claim
38 words
An arrangement as defined in claim 4, wherein said monitoring means comprises a tachometer generator mechanically coupled to the motor and a potentiometer connected across said generator and having a tap constituting the output of said monitoring means.
Claim 8
Dependent Claim
65 words
An arrangement as defined in claim 1, wherein said source means comprises a voltage source, a power transistor having an emitter-collector path connected in series with the motor, the series connection of said transistor and the motor being connected across said voltage source, and a driver tansistor for driving said power transistor and having a base connected to the output of said astable multivibrator means.
Claim 9
Dependent Claim
20 words
An arrangement as defined in claim 1; and further including a diode connected directly across the terminals of the motor.
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) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |