US3898545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor control circuit
Assignee: DECISION DATA Inc A CORP OF
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Filing: 1973-05-25
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Granted: 1975-08-05
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Expires: 1993-05-25
Abstract
Abstract A motor control circuit for maintaining a d-c electric motor at a constant speed, including a speed sensing means connected to the d-c electric motor to generate motor pulses whose duration is inversely proportional to the speed of the d-c electric motor, a bistable means for providing a continuous drive signal to the d-c electric motor and responsive to the application of the motor pulses and to the application of reference pulses generated by the motor pulses. The bistable means drives the d-c electric motor as long as the fixed duration of the reference pulses is shorter than the duration of the motor pulses being generated due to the rotation of the armature of the electric motor. Delay means are provided in the circuit to prevent ambiquity at the bistable means due to the simultaneous application of both the motor pulses and reference pulses to the bistable means.
Inventors
- 👤 Paul L Coppa
- 👤 Louis G Orsatti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:55
CPC Classifications
H; H02; H02P; H02P23/00; H02P23/22; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/921; Y10S388/923; Y10S388/933
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
155 words
A motor control circuit for maintaining an armature of a d-c electric motor at constant speed, comprising: speed sensing means responsive to the armature rotation for producing a motor signal, the period of which is inversely proportional to the armature speed; a time delay circuit which delays the leading edge of the motor signal in each motor signal period; a retriggerable one-shot circuit responsive to the delayed leading edges of the motor signal to produce a pulse of a fixed reference width only during those motor signal periods which are greater than the reference width; and a bistable circuit having input connections to receive said motor signal and said reference pulses and being set to a first state for applying a continuous drive signal to said motor so long as said one-shot circuit produces reference pulses and to be set to its other state during motor signal periods which are shorter than the reference width.
Claim 2
Dependent Claim
155 words
A motor control circuit for maintaining an armature of a d-c electric motor at constant speed, comprising: speed sensing means responsive to the armature rotation for producing a motor signal, the period of which is inversely proportional to the armature speed; a time delay circuit which delays the leading edge of the motor signal in each motor signal period; a retriggerable one-shot circuit responsive to the delayed leading edges of the motor signal to produce a pulse of a fixed reference width only during those motor signal periods which are greater than the reference width; and a bistable circuit having input connections to receive said motor signal and said reference pulses and being set to a first state for applying a continuous drive signal to said motor so long as said one-shot circuit produces reference pulses and to be set to its other state during motor signal periods which are shorter than the reference width.
Claim 3
Dependent Claim
35 words
The motor control circuit of claim 1 wherein the time delay circuit is an edge-delay circuit which provides about a one microsecond delay of the leading edge of said motor signal in each signal period.
Claim 4
Dependent Claim
16 words
The motor control circuit of claim 1 wherein the speed sensing means is an optical tachometer.
Claim 5
Dependent Claim
37 words
The motor control circuit of claim 1 wherein the bistable drive means is a D-type flip-flop having D and clock inputs, corresponding to said input connections, and connected to receive said reference pulses and motor signal, respectively.
Claim 6
Dependent Claim
214 words
A motor control circuit for maintaining an armature of a d-c electric motor at constant speed, comprising: speed sensing means responsive to the armature rotation for producing a motor signal, the period of which is inversely proportional to the armature speed; a retriggerable one-shot circuit responsive to said motor signal to produce a pulse of a fixed reference width during only those motor signal periods which are greater than the reference width; a time delay circuit for delaying the leading edges of the reference pulses; a sampling pulse generator responsive to said motor signal to produce during each motor signal period a sampling pulse; a circuit for producing a reset pulse in response to the coincidence of a reference pulse and a sampling pulse, the sampling pulse width being shorter than the delay time of said delay circuit, whereby said coincidence occurs only when the motor signal period is less than the reference width; and a bistable circuit having input connections to receive said reference pulses and said reset pulses and being set to a first state for applying a continuous drive signal to said motor so long as said retriggerable one-shot circuit produces reference pulses and to be set to its other state during motor signal periods in which said reset pulses occur.
Claim 7
Dependent Claim
214 words
A motor control circuit for maintaining an armature of a d-c electric motor at constant speed, comprising: speed sensing means responsive to the armature rotation for producing a motor signal, the period of which is inversely proportional to the armature speed; a retriggerable one-shot circuit responsive to said motor signal to produce a pulse of a fixed reference width during only those motor signal periods which are greater than the reference width; a time delay circuit for delaying the leading edges of the reference pulses; a sampling pulse generator responsive to said motor signal to produce during each motor signal period a sampling pulse; a circuit for producing a reset pulse in response to the coincidence of a reference pulse and a sampling pulse, the sampling pulse width being shorter than the delay time of said delay circuit, whereby said coincidence occurs only when the motor signal period is less than the reference width; and a bistable circuit having input connections to receive said reference pulses and said reset pulses and being set to a first state for applying a continuous drive signal to said motor so long as said retriggerable one-shot circuit produces reference pulses and to be set to its other state during motor signal periods in which said reset pulses occur.
Claim 8
Dependent Claim
36 words
The motor control circuit of claim 5 wherein the bistable drive means is an R-S flip-flop, having reset and set inputs, corresponding to said input connections, and connected to receive said reset and reference pulses, respectively.
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) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |