US3582745A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speed control circuit motor
Assignee: Janome Corp
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Filing: 1967-11-20
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Granted: 1971-06-01
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Expires: 1987-11-20
Abstract
Abstract This invention is concerned with a speed control for an electric motor which has been devised after noticing that the motor current increases or decreases approximately in proportion to the size of the load thereon and which control consists of a series circuit composed of an alternating current supply source, a motor and a symmetrical semiconductor switching element presenting low impedance by means of a trigger pulse, a phase adjusting circuit providing a trigger pulse on this circuit, and an ignition circuit, and a primary winding of a feedback transformer connected in series between said current supply source and the motor, and a secondary winding connected between said phase adjusting circuit and the supply source, taking polarity into consideration, thus the motor current flowing through said switching element is impressed to said primary winding, and this current is transformed as voltage to this secondary winding, and a polarity of this transformed voltage is fed back as a voltage of a reversed polarity to the polarity of the voltage to be supplied to the phase adjusting circuit from the current supply source to sensitively respond to the fluctuation of the load so that the ignition phase of said switching element is controlled automatically.
Inventors
- 👤 Yasukata Eguchi
- 👤 Kenji Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:43
CPC Classifications
H; H02; H02P; H02P25/00; H02P25/02; H02P25/10; H02P25/14; H02P25/145
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
162 words
A speed control circuit for an electric motor comprising a source of electrical current, a main circuit having a motor, a symmetrical semiconductor switching element and a secondary winding of a pulse transformer, connected in series, a phase adjusting circuit composed of a feedback transformer, variable resistor, a plurality of fixed resistors and a plurality of condensers, and a trigger circuit having a triggerable symmetrical semiconductor switching element and a primary winding of said pulse transformer, and said primary winding of said feedback transformer being connected between said motor and said source of current whereby the motor current flowing through the semiconductor switching element of said main circuit flows through said primary winding, and said secondary winding of said feedback transformer being connected between said variable resistor and said source of current, so as to give voltage induced on said secondary winding a reversed polarity to the polarity of the voltage impressed on said phase adjusting circuit from said source of current.
Claim 2
Dependent Claim
162 words
A speed control circuit for an electric motor comprising a source of electrical current, a main circuit having a motor, a symmetrical semiconductor switching element and a secondary winding of a pulse transformer, connected in series, a phase adjusting circuit composed of a feedback transformer, variable resistor, a plurality of fixed resistors and a plurality of condensers, and a trigger circuit having a triggerable symmetrical semiconductor switching element and a primary winding of said pulse transformer, and said primary winding of said feedback transformer being connected between said motor and said source of current whereby the motor current flowing through the semiconductor switching element of said main circuit flows through said primary winding, and said secondary winding of said feedback transformer being connected between said variable resistor and said source of current, so as to give voltage induced on said secondary winding a reversed polarity to the polarity of the voltage impressed on said phase adjusting circuit from said source of current.
Claim 3
Dependent Claim
118 words
A speed control circuit for an electric motor as described in claim 1, wherein said phase adjusting circuit is respectively connected in series with a plurality of resistors on one side of said variable resistor, fixed resistor and one of said condensers on the other side of said variable resistor and these series circuits are connected in parallel, and said phase adjusting circuit is provided in parallel, and said phase adjusting circuit is provided in parallel with said motor of said main circuit and the symmetrical semiconductor element so that a wiper of said variable resistor is connected in series with the secondary winding of said feedback transformer so as to form a path for the feedback signal.
Claim 4
Dependent Claim
141 words
A speed control circuit for an electric motor comprising a source of electrical current, a main circuit having a motor, a symmetrical semiconductor switching element and a secondary winding of a pulse transformer, connected in series, a phase adjusting circuit having a feedback transformer, variable resistor provided in parallel with said main circuit, a fixed resistor and a plurality of condensers, a trigger circuit havIng a triggerable symmetrical semiconductor switching element and the primary winding of said pulse transformer, and, the primary winding of said feedback transformer being connected between said motor and said source of current, and the secondary winding of said feedback transformer being connected to terminals of said condensers for rendering the voltage induced on said secondary winding a reversed polarity to the polarity of the voltage impressed on said phase adjusting circuit from said source of current.
Claim 5
Dependent Claim
141 words
A speed control circuit for an electric motor comprising a source of electrical current, a main circuit having a motor, a symmetrical semiconductor switching element and a secondary winding of a pulse transformer, connected in series, a phase adjusting circuit having a feedback transformer, variable resistor provided in parallel with said main circuit, a fixed resistor and a plurality of condensers, a trigger circuit havIng a triggerable symmetrical semiconductor switching element and the primary winding of said pulse transformer, and, the primary winding of said feedback transformer being connected between said motor and said source of current, and the secondary winding of said feedback transformer being connected to terminals of said condensers for rendering the voltage induced on said secondary winding a reversed polarity to the polarity of the voltage impressed on said phase adjusting circuit from said source of current.
References Cited (Backward Citations)
US3293523A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |