US3909690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-exciting direct current motors
Assignee: Sansui Electric Co Ltd
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Filing: 1974-03-29
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Granted: 1975-09-30
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Expires: 1994-03-29
Abstract
Abstract In a self-exciting direct current motor of the type including amplifier means for amplifying a position signal produced by starting position detecting means and the electromotive force induced in an armature coil wound on a magnetic pole of the stator in accordance with the rotation of the rotor, and a selfexciting circuit for supplying the output of the amplifier means to the field coil wound on the magnetic pole of the rotor as a self-excitation field current, there are provided means for detecting only the forward rotation of the rotor, means for converting the output signal of the detecting means into a continuous signal, and means for supplying the continuous signal to the self-exciting circuit at the end of a predetermined period starting with a point of time at which the signal indicating the forward rotation is detected, thereby effecting the selective operation of the self-exciting circuit so as to amplify only the voltage induced in the armature coils.
Inventors
- 👤 Naokatsu Sugiura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:24
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
247 words
In a self-exciting direct current motor of the type comprising a rotor having a plurality of magnetic poles in the form of a permanent magnet, a stator positioned about said rotor and having a plurality of magnetic poles respectively wound with field coils and armature coils, starting position detecting means positioned adjacent said rotor and including a plurality of position detecting elements to detect the angular position of the rotor for producing a position signal of the rotor, a selfexciting circuit including amplifier means for amplifying said position signal and the electromotive forces induced in said armature coils in accordance with the rotation of said rotor for supplying the amplified power to said field coils thus causing the rotor to rotate continuously, and means for connecting a position signal and an armature coil to an amplifier means as inputs and for connecting an amplifier means output to a field coil, the improvement which comprises: means having an armature coil as an input for detecting a signal indicating only the forward rotation of said rotor and providing an output; means for converting the output of said signal detecting means into a continuous signal; and means for supplying said continuous signal to said self-exciting circuit at the end of a predetermined period starting with a point of time at which the signal indicating said forward rotation is detected, thereby effecting the selective operation of said self-exciting circuit so as to amplify only the voltage induced in said armature coils.
Claim 2
Dependent Claim
247 words
In a self-exciting direct current motor of the type comprising a rotor having a plurality of magnetic poles in the form of a permanent magnet, a stator positioned about said rotor and having a plurality of magnetic poles respectively wound with field coils and armature coils, starting position detecting means positioned adjacent said rotor and including a plurality of position detecting elements to detect the angular position of the rotor for producing a position signal of the rotor, a selfexciting circuit including amplifier means for amplifying said position signal and the electromotive forces induced in said armature coils in accordance with the rotation of said rotor for supplying the amplified power to said field coils thus causing the rotor to rotate continuously, and means for connecting a position signal and an armature coil to an amplifier means as inputs and for connecting an amplifier means output to a field coil, the improvement which comprises: means having an armature coil as an input for detecting a signal indicating only the forward rotation of said rotor and providing an output; means for converting the output of said signal detecting means into a continuous signal; and means for supplying said continuous signal to said self-exciting circuit at the end of a predetermined period starting with a point of time at which the signal indicating said forward rotation is detected, thereby effecting the selective operation of said self-exciting circuit so as to amplify only the voltage induced in said armature coils.
Claim 3
Dependent Claim
157 words
A self-exciting direct current motor according to claim 1 wherein said means for detecting a signal indicating only thE forward rotation comprises an AND gate circuit which detects the phase coincidence of the positive half cycles of the output of one of said position detecting elements and the positive half cycles of the output of one armature coil corresponding to said one position detecting element, said means for converting the output of said signal detecting means into said continuous signal comprises a smoothing circuit for smoothing the output of said AND gate circuit, and means for effecting said selective operation comprises a delay circuit for delaying the output of said smoothing circuit for said predetermined period, and means responsive to the output of said delay circuit for preventing from amplifying the positive half cycles of the outputs of said position detecting elements and for continuing the supply of said positive half cycles to said AND gate circuit.
Claim 4
Dependent Claim
147 words
A self-exciting direct current motor according to claim 2 wherein said means for preventing from amplifying the positive half cycles of the outputs of said position detecting elements and for continuing the supply of said positive half cycles comprises input resistors for applying the positive half cycles of the outputs of the respective position detecting elements to the input of said amplifier means through diodes, means for by-passing said positive half-cycles from the junctions between the respective input resistors and the respective diodes through a circuit including other diodes and a switching element, means responsive to the output of said delay circuit for maintaining said switching element in its conductive state, and means for supplying the positive half cycle output at the junction between one of said position detecting elements and one of said input resistors to one input of said AND gate circuit through a diode.
Claim 5
Dependent Claim
111 words
A self-exciting direct current motor according to claim 1 wherein said means for detecting a signal indicating only the forward rotation of the rotor comprises a forward rotation detecting circuit responsive to the output voltage of the first one of said armature coils and the output voltage of the second one of said armature coils which lags less than 180 electrical degrees than the output voltage of said first armature coil for producing output pulses indicating the forward rotation, means for converting said output pulses into a continuous signal, and means for supplying said continuous signal to said starting position detecting means for terminating the operation thereof after said predetermined period.
Claim 6
Dependent Claim
100 words
A self-exciting direct current motor according to claim 4 wherein said forward rotation detecting circuit comprises a first limiter which produces a rectangular wave in phase coincidence with the positive half cycles of the output of said first armature coil, a second limiter which produces a rectangular wave in phase coincidence with positive half cycles of the output of said second armature coil, a circuit for differentiating the output of said second limiter, and means for producing an output pulse each time when the positive pulse output of said differentiating circuit and the output of said first limiter occur simultaneously.
References Cited (Backward Citations)
US3290572A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |