US3740631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voltage comparator controlled motor starting circuit
Assignee: ECC CORP US
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Filing: 1971-07-23
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Granted: 1973-06-19
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Expires: 1991-07-23
Abstract
Abstract A speed responsive motor starting circuit includes a pair of bilateral triode switches connected to the motor start system for controlling the current flow therethrough. A capacitor is connected to the control electrode of one of the triode switches for supplying enabling current thereto. Current supplied to the capacitor by an A. C. supply, the amount supplied being controlled by a comparator switch in accordance with the relative magnitudes of two voltages applied to the comparator switch. One such voltage is inversely proportional to the speed of the motor and is generated by a current-sensing transformer coupled in circuit with the motor run winding. The other such voltage is applied by the A. C. supply through a diode to the comparator switch. Various solid state devices may be utilized as the comparator switch.
Inventors
- 👤 D Fricker
- 👤 T Whittaker
- 👤 L Fink
- 👤 S Lam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:40
CPC Classifications
H; H02; H02P; H02P1/00; H02P1/16; H02P1/42
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
110 words
In a motor system including a run winding, a starting system, and an A.C. supply, a speed responsive motor starting circuit comprising: switching means connected in series with said starting system and responsive to gating current for supplying current from said A.C. supply to said starting system; current sensing means connected in series with said run winding and responsive to the current flowing therethrough for generating a first voltage; means connected in circuit with said A.C. supply for generating a second voltage; and means for supplying gating current to said switching means in response to said first voltage reaching a certain amplitude relatIve to the amplitude of said second voltage.
Claim 2
Dependent Claim
110 words
In a motor system including a run winding, a starting system, and an A.C. supply, a speed responsive motor starting circuit comprising: switching means connected in series with said starting system and responsive to gating current for supplying current from said A.C. supply to said starting system; current sensing means connected in series with said run winding and responsive to the current flowing therethrough for generating a first voltage; means connected in circuit with said A.C. supply for generating a second voltage; and means for supplying gating current to said switching means in response to said first voltage reaching a certain amplitude relatIve to the amplitude of said second voltage.
Claim 3
Dependent Claim
71 words
The circuit of claim 1 wherein said switching means comprises first and second bilateral triode switches, each having two power electrodes and a control electrode, the power electrodes of said first bilateral triode switch being connected in series with said starting system and the power electrodes of said second bilateral triode switch being connected in series with the control electrode of said first bilateral triode switch to supply gating current thereto.
Claim 4
Dependent Claim
33 words
The circuit of claim 1 wherein said current sensing means comprises a transformer having a first winding connected in series with said run winding and a second winding coupled to said supplying means.
Claim 5
Dependent Claim
43 words
The circuit of claim 1 wherein said supplying means comprises: a capacitor connected to said switching means; and a comparator switch for causing said capacitor to charge when said first voltage reaches a certain amplitude relative to the amplitude of said second voltage.
Claim 6
Dependent Claim
75 words
The circuit of claim 4 wherein said comparator switch comprises: a first resistor connected to said current sensing means; a second resistor connected to said second voltage generating means and in series with said first resistor; and a programmable unijunction transistor whose gate electrode is connected to the junction of said first and second resistors, whose cathode is connected to said second voltage generating means, and whose anode is connected to said A. C. supply.
Claim 7
Dependent Claim
75 words
The circuit of claim 4 wherein said comparator switch comprises: a first resistor connected to said current sensing means; a second resistor connected to said second voltage generating means and in series with said first resistor; and a silicon controlled rectifier whose gate electrode is connected to the junction of said first and second resistors, whose anode is connected to said second voltage generating means, and whose cathode is connected to said A. C. supply.
Claim 8
Dependent Claim
50 words
The circuit of claim 4 wherein said comparator switch comprises a unijunction transistors whose emitter is connected to said A. C. supply and one of whose base electrodes is connected to said current sensing means and the other of whose base electrodes is connected to said second voltage generating means.
Claim 9
Dependent Claim
72 words
The circuit of claim 4 wherein said comparator switch comprises: a first resistor connected to said current sensing means; a second resistor connected to said second voltage generating means and in series with said first resistors; and a transistor whose base is connected to the junction of said first and second resistors, whose collector is connected to said second voltage generating means, and whose emitter is connected to said A. C. supply.
Claim 10
Dependent Claim
65 words
The circuit of claim 4 wherein said comparator switch comprises: a first transistor whose base is connected to said current sensing means; and a second transistor whose base is connected to the collector of said first transistor, whose emitter is connected to the emitter of said first transistor and to said A. C. supply and whose collector is connected to said second voltage generating means.
Claim 11
Dependent Claim
203 words
In a motor system including a run winding, a starting system, and an A. C. supply, a speed responsive motor starting circuit comprising: first and second bilateral triode switches, each having two power electrodes and a control electrode, the power electrodes of said first bilateral triode switch being connected in series with said starting system and the power electrodes of said second bilateral triode switch being connected in series with the control electrode of said first bilateral triode switch for supplying gating current thereto; a first capacitor coupled to the control electrode of said second bilateral triode switch for supplying gating current thereto; means connected to a first terminal of said A. C. supply for generating a first voltage; means connected to said first voltage generating meaNs for charging said first capacitor; current sensing means responsive to current flowing through said run winding for generating a second voltage; a second capacitor connected to said current sensing means for storing said second voltage; and a comparator switch for conducting current from said charging means to a second terminal of said A. C. supply in response to certain relative amplitudes of said first and second voltages, to thereby inhibit the charging of said first capacitor.
Claim 12
Dependent Claim
203 words
In a motor system including a run winding, a starting system, and an A. C. supply, a speed responsive motor starting circuit comprising: first and second bilateral triode switches, each having two power electrodes and a control electrode, the power electrodes of said first bilateral triode switch being connected in series with said starting system and the power electrodes of said second bilateral triode switch being connected in series with the control electrode of said first bilateral triode switch for supplying gating current thereto; a first capacitor coupled to the control electrode of said second bilateral triode switch for supplying gating current thereto; means connected to a first terminal of said A. C. supply for generating a first voltage; means connected to said first voltage generating meaNs for charging said first capacitor; current sensing means responsive to current flowing through said run winding for generating a second voltage; a second capacitor connected to said current sensing means for storing said second voltage; and a comparator switch for conducting current from said charging means to a second terminal of said A. C. supply in response to certain relative amplitudes of said first and second voltages, to thereby inhibit the charging of said first capacitor.
Claim 13
Dependent Claim
28 words
The circuit of claim 10 further comprising a resistive means connecting said second capacitor to said second terminal of said A. C. supply for discharging said second capacitor.
Claim 14
Dependent Claim
27 words
The circuit of claim 11 wherein said first voltage generating means includes a resistor and a first diode connected in series for generating a direct current voltage.
Claim 15
Dependent Claim
25 words
The circuit of claim 12 further comprising a second diode for applying a direct current voltage from said current sensing means for said second capacitor.
Claim 16
Dependent Claim
33 words
The circuit of claim 13 wherein said current sensing means comprising a transformer having a first winding connected in series with said run winding and a second winding connected to said second diode.
Claim 17
Dependent Claim
91 words
The circuit of claim 10 wherein said comparator switch comprises: a first resistor connected to said first capacitor and said current sensing means; a second resistor connected to said first voltage generating means and said charging means and in series with said first resistor; and a programmable unijunction transistor whose gate electrode is connected to the junction of said first and second resistors, whose cathode is connected to said first voltage generating means and said charging means, and whose anode is connected to said second terminal of said A. C. supply.
Claim 18
Dependent Claim
91 words
The circuit of claim 10 wherein said comparator switch comprises: a first resistor connected to said second capacitor and said current sensing means; a second resistor connected to said first voltage generating means and said charging means and in series with said first resistor; and a silicon controlled rectifier whose gate electrode is connected to the junction of said first and second resistors, whose anode is connected to said first voltage generating means and said charging means, and whose cathode is connected to said second terminal of said A. C. supply.
Claim 19
Dependent Claim
60 words
The circuit of claim 10 wherein said comparator switch comprises a unijunction transistor whose emitter is connected to said second terminal of said A. C. supply and one of whose base electrodes is connected to said second capacitor and said current sensing means and whose other base electrode is connected to said first voltage generating means and said charging means.
Claim 20
Dependent Claim
81 words
The circuit of claim 10 wherein said comparator switch comprises: a first resistor connected to said second capacitor and said current sensing means; a second resistor connected to said first voltage generating means and said charging means; and a transistor whose base is connected to the junction of said first and second resistors, whose collector is connected to said first voltage generating means and said charging means, and whose emitter is connected to said second terminal of said A. C. supply.
Claim 21
Dependent Claim
77 words
The circuit of claim 10 wherein said comparator switch comprises: a first transistor whose base is connected to said second capacitor and said current sensing means; and a second transistor whose base is connected to the collector of said first transistor, whose emitter is connected to the emitter of said first transistor and to said second terminal of said A. C. supply, and whose collector is connected to said first voltage generating means and said charging means.
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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |