Patent US361528A successfully refreshed from Google Patents.
Patent US3857077A successfully refreshed from Google Patents.
US3857077A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Speed and direction control apparatus for dc motors
Assignee: Magnetic Labor Inc
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Filing: 1973-04-27
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Granted: 1974-12-24
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Expires: 1993-04-27
Abstract
Abstract A speed and direction control apparatus for DC motors supplied from an AC power line. The control apparatus includes a triggerable bi-directional current conducting element selectively triggered to pass either positive or negative half cycles of the incoming AC signal to thereby control the direction of motor rotation. Triggering of the bi-directional current conducting element may be accomplished by using a photoelectric switch control circuit. In the specific embodiment of the invention the DC motor in combination with the control apparatus is adapted to operate as a servosystem.
Inventors
- 👤 T Kasmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:21
CPC Classifications
B; B66; B66B; B66B1/00; B66B1/34; B66B1/36; B66B1/40; G; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/18; H; H02; H02M; H02M1/00; H02M1/08; H02M1/088; H02M1/092; H02P; H02P25/00; H02P25/02; H02P25/10; H02P25/14; H02P7/00; H02P7/03; H02P7/05
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
257 words
A speed and direction control circuit for a DC motor comprising: triggerable bi-directional current conducting means connected in series with said DC motor and an AC power source, bi-directional breakdown means connected to trigger said triggerable bi-directional current conducting means when the breakdown voltage of said breakdown means is exceeded, RC timing circuit means connected to the AC power source and to said bi-directional breakdown means for controlling which half cycle and the time during that half cycle of the AC power source when said bi-directional current conducting means is triggered, said RC timing circuit means including a capacitor connected to discharge through said bi-directional breakdown means when the voltage across said capacitor exceeds said breakdown voltage, first series-connected photocell and diode circuit means and second series-connected photocell and diode circuit means, said first and second series-connected photocell and diode circuit means being connected in parallel to control the direction and rate of charging of said capacitor, the diodes in said first and second series-connected photocell and diode circuits means being oppositely poled with respect to one another, lamp means, and movable mask means interposed between said lamp means and the photocells in said first and second series-connected photocell and diode circuits means, said mask means having first and second varying transmissibility aperture means disposed with respect to one another along the direction of movement of said movable mask means each of said aperture means controlling the illumination of one of said photocells by said lamp means as a function of the movement of said mask means.
Claim 2
Dependent Claim
257 words
A speed and direction control circuit for a DC motor comprising: triggerable bi-directional current conducting means connected in series with said DC motor and an AC power source, bi-directional breakdown means connected to trigger said triggerable bi-directional current conducting means when the breakdown voltage of said breakdown means is exceeded, RC timing circuit means connected to the AC power source and to said bi-directional breakdown means for controlling which half cycle and the time during that half cycle of the AC power source when said bi-directional current conducting means is triggered, said RC timing circuit means including a capacitor connected to discharge through said bi-directional breakdown means when the voltage across said capacitor exceeds said breakdown voltage, first series-connected photocell and diode circuit means and second series-connected photocell and diode circuit means, said first and second series-connected photocell and diode circuit means being connected in parallel to control the direction and rate of charging of said capacitor, the diodes in said first and second series-connected photocell and diode circuits means being oppositely poled with respect to one another, lamp means, and movable mask means interposed between said lamp means and the photocells in said first and second series-connected photocell and diode circuits means, said mask means having first and second varying transmissibility aperture means disposed with respect to one another along the direction of movement of said movable mask means each of said aperture means controlling the illumination of one of said photocells by said lamp means as a function of the movement of said mask means.
Claim 3
Dependent Claim
56 words
The control circuit of claim 1, wherein said varying transmissibility apertures comprise shaped apertures positioned on said mask with respect to the position of said photocells and lamp means such that when light from said lamp means passes through one of said apertures to one of said photocells, substantially no light impinges on the other photocell.
Claim 4
Dependent Claim
29 words
The control circuit of claim 2 wherein the shaped apertures are triangular with their apices pointed in opposite directions along the direction of movement of said movable mask means.
Claim 5
Dependent Claim
75 words
The control circuit of claim 1 further comprising a resistor connected between said first capacitor and said bi-directional breakdown means and a second capacitor connected to the junction of said resistor and said bi-directional breakdown means and in parallel with said first capacitor, said resistor and said second capacitor serving to provide a time delay thereby extending the turn-on range of said circuit for applications where very slow running speeds of said motor are desired.
Claim 6
Dependent Claim
82 words
The control circuit of claim 1 further comprising third and fourth diodes respectively connected in shunt with the photocells in said first and second series-connected photocell and diode circuits means, said third and fourth diodes being oppositely poled to the diodes in their respective circuits and serving to provide conduction paths for any residual charge on said capacitor when the diodes in their respective circuits are non-conducting whereby very slow speeds of said motor are permitted thereby greatly extending the speed range.
Claim 7
Dependent Claim
32 words
The control circuit of claim 1 wherein said first and second series-connected photocell and diode circuit means are in turn connected in series with said capacitor and the source of AC power.
Claim 8
Dependent Claim
80 words
The control circuit of claim 6 further comprising a first resistor connected in shunt with the diode in said first series-connected photocell and diode circuit means and said capacitor, and a second resistor connected in shunt with the diode in said second series-connected photocell and diode circuit means and said capacitor, said first and second resistors having values selected so that the photocells operate in the large slope regions of their characteristic curves whereby more rapid response times are obtained.
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) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |