US3609494A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speed-controlling apparatus for dc motor
Assignee: Hitachi Ltd
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Filing: 1968-11-14
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Granted: 1971-09-28
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Expires: 1988-11-14
Abstract
Abstract A speed-controlling apparatus for DC motors, wherein a closed series circuit is constituted by a DC power source, a DC motor and the emitter and collector of a first transistor, whereby the conductivity between the emitter and the collector of the transistor is controlled to thereby achieve constant speed control with respect to the DC motor. Further, a biasing circuit for supplying a constant base current to a second transistor is formed by a Zener diode and a resistor. The output of an AC generator which is mechanically conducted with said DC motor is rectified by means of a diode. The output circuit of the AC generator is combined with said biasing circuit in such polarity that the current of said biasing circuit is positively shunted by the rectified output current, so that the conductivity between the emitter and the collector of the first transistor is controlled in accordance with variation in the collector potential of the second transistor, thereby maintaining the speed of the DC motor constant.
Inventors
- 👤 Tadashi Takahashi
- 👤 Kazuo Onishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:16
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/288; H02P7/2885; Y; Y10; Y10S; Y10S388/00; Y10S388/923; Y10S388/93
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
160 words
A control apparatus comprising: an electric motor; a DC power source; a first transistor connected between said electric motor and said DC power source; a generator mechanically connected with said motor; second transistor coupled to said first transistor to control the conduction thereof, whereby said DC power source will supply current to said motor through said first transistor; a substantially constant current-biasing circuit connected to the base of said second transistor for supplying current thereto; and means, connected between said generator and said biasing circuit and responsive to the output of said generator for positively shunting current delivered by said biasing circuit, said shunting means including a temperature-sensitive element for cancelling the variations in the conductivity of said second transistor due to temperature change, said temperaturesensitive element comprising a diode connected in series with said generator and the connection of said biasing circuit with said second transistor whereby the speed of said motor will be maintained at a constant rate.
Claim 2
Dependent Claim
160 words
A control apparatus comprising: an electric motor; a DC power source; a first transistor connected between said electric motor and said DC power source; a generator mechanically connected with said motor; second transistor coupled to said first transistor to control the conduction thereof, whereby said DC power source will supply current to said motor through said first transistor; a substantially constant current-biasing circuit connected to the base of said second transistor for supplying current thereto; and means, connected between said generator and said biasing circuit and responsive to the output of said generator for positively shunting current delivered by said biasing circuit, said shunting means including a temperature-sensitive element for cancelling the variations in the conductivity of said second transistor due to temperature change, said temperaturesensitive element comprising a diode connected in series with said generator and the connection of said biasing circuit with said second transistor whereby the speed of said motor will be maintained at a constant rate.
Claim 3
Dependent Claim
54 words
A control apparatus according to claim 1, wherein the output of said generator is connected to said shunting means through a variable resistor changeover switch, and wherein said diode has one electrode thereof connected to said changeover switch and the other electrode thereof connected through a resistor to the base of said second transistor.
Claim 4
Dependent Claim
29 words
A control apparatus according to claim 2, wherein the junction point of said diode and resistor is connected through a capacitor to one side of said DC power source.
Claim 5
Dependent Claim
30 words
A control apparatus according to claim 2, wherein the polarities of the respective electrodes of said diode and said second transistor which are connected to said resistor are the same.
Claim 6
Dependent Claim
32 words
A control apparatus according to claim 1, wherein said means for positively shunting at least part of the bias current includes a varistor representing a negative characteristic with respect to temperature variation.
Claim 7
Dependent Claim
36 words
A control apparatus according to claim 1, wherein an AC generator is used as the generator mechanically connected with the electric motor, and said generator is connected with the biasing circuit through at least one diode.
Claim 8
Dependent Claim
33 words
A control apparatus according to claim 1, wherein said means for positively shunting at least part of the bias current includes a resistance element of which the resistance value can be artificially changed.
Claim 9
Dependent Claim
48 words
A control apparatus according to claim 1, wherein the base of said second transistor is connected with one terminal of a potentiometer-type resistor, the other terminal of said resistor is connected with said shunting means, and the bias current is supplied to the intermediate terminal of said resistor.
Claim 10
Dependent Claim
52 words
A control apparatus according to claim 1, wherein said biasing circuit includes a series circuit of a Zener diode and a resistor which is connected across a pair of power lines, and a terminal of said Zener diode is connected with the base circuit of said second transistor through a high resistance.
Claim 11
Dependent Claim
69 words
A control apparatus according to claim 1, wherein said biasing circuit includes a third transistor of which the emitter and collector are connected with a power line and the base circuit of said second transistor, respectively, the emitter circuit of said third transistor further has a resistor and Zener diode inserted therein, and wherein said third transistor further has a resistor connected between its base and another power line.
Claim 12
Dependent Claim
42 words
A contrOl apparatus according to claim 3, further including a first resistor inserted in the emitter circuit of said second transistor, and wherein a power source voltage is applied to the emitter side terminal of said first resistor through a second resistor.
Claim 13
Dependent Claim
60 words
A control apparatus according to claim 1, wherein said generator is an AC generator, and including means for rectifying and smoothing the output of said AC generator to a current containing a ripple component, whereby the bias current is shunted so that the base current level which renders said second transistor operative falls within the range of the ripple component.
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 |