US3609487A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dc motor and constant-speed control circuit
Assignee: ARMEC CORP
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Filing: 1969-10-29
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Granted: 1971-09-28
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Expires: 1989-10-29
Abstract
Abstract In accordance with a preferred embodiment of the invention, a DC motor is both driven and controlled through a common winding by providing a circuit which includes both power and control portions and is preferably self-oscillatory in the absence of rotor motion and at a frequency related to desired rotor speed to define, in conjunction with rotor-generated signals, limits of motor speed. The power portion includes an electronic switch and motor current limiter and the control portion includes an amplifier stage to operate the switch and two separate feedback paths are provided from the power portion to the amplifier stage. A mechanical resonator is coupled to the rotor to be excited into resonance as the motor reaches synchronous speed, and an electromagnetic pickup from the resonator feeds a signal into the amplifier stage to furnish a dominating control signal, thus synchronizing the motor to the resonator to achieve precise motor speed while enabling the motor to be either self-starting or, if desired, capable of starting with a very slight push, and to recover synchronous speed following disturbance to rotor speed for any reason including loss of power.
Inventors
- 👤 William W Allison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:27
CPC Classifications
H; H02; H02K; H02K29/00; H02K29/06; H02K29/12; G; G04; G04C; G04C3/00; G04C3/16; G04C3/165
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
149 words
In a DC motor: a motor winding; magnetic pole structure inductively coupled with the winding and including complementary rotor and stator portions; means to mount the rotor for continuous rotation in one direction or the other; means to connect a DC source to the winding; circuit means including a power circuit portion and a control circuit portion and having electronic switching means to connect the DC source to the winding to control the energization of the winding from the source, said circuit means and winding means being selfoscillatory in the absence of rotor motion; and means to connect the winding to the control circuit portion to modify the action of said control circuit portion by voltage due to rotor motion through electromagnetically generated signals in the motor winding to actuate the switching means, whereby the switching action accelerates rotor motion to a desired speed and thereafter maintains such speed.
Claim 2
Dependent Claim
149 words
In a DC motor: a motor winding; magnetic pole structure inductively coupled with the winding and including complementary rotor and stator portions; means to mount the rotor for continuous rotation in one direction or the other; means to connect a DC source to the winding; circuit means including a power circuit portion and a control circuit portion and having electronic switching means to connect the DC source to the winding to control the energization of the winding from the source, said circuit means and winding means being selfoscillatory in the absence of rotor motion; and means to connect the winding to the control circuit portion to modify the action of said control circuit portion by voltage due to rotor motion through electromagnetically generated signals in the motor winding to actuate the switching means, whereby the switching action accelerates rotor motion to a desired speed and thereafter maintains such speed.
Claim 3
Dependent Claim
53 words
A DC motor as in claim 1, said circuit means being self-oscillatory at a frequency which is the center of a band of frequencies over which the winding can actuate the switching means when the rotor is turning, said self-oscillatory circuit means thereby controlling an upper limit to the speed of the rotor.
Claim 4
Dependent Claim
23 words
A DC motor as in claim 1, including means to connect the circuit means to a DC source independently of the motor winding.
Claim 5
Dependent Claim
14 words
A DC motor as in claim 1, said control portion including a phase inverter.
Claim 6
Dependent Claim
35 words
A DC motor as in claim 1, including an amplifier stage and a regenerative feedback path connected between the winding and the input to the amplifier stage and responsive to voltages appearing across the winding.
Claim 7
Dependent Claim
33 words
A DC motor as in claim 5, including a degenerative feedback path connected between the power circuit portion and the input to the amplifier stage and responsive to current passing through the winding.
Claim 8
Dependent Claim
91 words
A DC motor as in claim 1, including a mechanical resonator having an electromagnetic signal pickup generator responsive to resonator motion, means to couple the rotor to the resonator to excite the resonator into its natural frequency of vibration when the rotor is at a speed corresponding to resonator frequency, and means responsive to the pickup signals generated by the resonator at resonance to actuate the switching means, said switching means including means responsive to the phase of the resonator signals to cause the resonator signals to dominate the switching action.
Claim 9
Dependent Claim
122 words
A DC motor as in claim 2, including a mechanical resonator having an electromagnetic signal pickup generator responsive to resonator motion, means to couple the rotor to the resonator to excite the resonator into its natural frequency of vibration when the rotor is at a speed corresponding to resonator frequency, said resonator frequency being substantially at or below the frequency corresponding to the maximum speed at which the rotor will turn without the resonator, and means responsive to the pickup signals generated by the resonator at resonance to energize the motor winding, whereby the controlled upper limit of rotor speed due to the selected self-oscillation frequency approximates synchronous speed as controlled by the resonator, thereby enabling the resonator to cApture the rotor.
Claim 10
Dependent Claim
39 words
A DC motor as in claim 8, including current-limiting means, said current-limiting means including a degenerative feedback path connected between the power circuit portion and the input to the amplifier stage and responsive to current passing through the winding.
Claim 11
Dependent Claim
123 words
In a DC motor: a motor winding; magnetic pole structure inductively coupled with the winding and including complementary rotor and stator portions; means to mount the rotor for continuous rotation in one direction or the other; means to connect a DC source to the winding; circuit means including a power circuit and a control circuit and having bistable electronic switching means connected in series with the DC source and the winding to control the energization of the winding from the source; means to connect the winding to the control circuit, said control circuit being responsive to rotor motion through electromagnetically generated signals in the motor winding to actuate the switching means; and current-limiting means independent of the DC source voltage to the winding.
Claim 12
Dependent Claim
123 words
In a DC motor: a motor winding; magnetic pole structure inductively coupled with the winding and including complementary rotor and stator portions; means to mount the rotor for continuous rotation in one direction or the other; means to connect a DC source to the winding; circuit means including a power circuit and a control circuit and having bistable electronic switching means connected in series with the DC source and the winding to control the energization of the winding from the source; means to connect the winding to the control circuit, said control circuit being responsive to rotor motion through electromagnetically generated signals in the motor winding to actuate the switching means; and current-limiting means independent of the DC source voltage to the winding.
Claim 13
Dependent Claim
27 words
A DC motor as in claim 10, including an amplifier, said current-limiting means including a degenerative feedback path connected between the power circuit portion and the amplifier.
Claim 14
Dependent Claim
21 words
A DC motor as in claim 10, including an amplifier and a regenerative feedback path from the winding to the amplifier.
Claim 15
Dependent Claim
24 words
A DC motor as in claim 12, said current-limiting means including a degenerative feedback path connected between the power circuit portion and the amplifier.
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) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |