US3739192A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non oscillating arcless switching or inductive d.c. loads
Assignee: Individual
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Filing: 1971-11-24
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Granted: 1973-06-12
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Expires: 1991-11-24
Abstract
Abstract A circuit interrupter for arclessly interrupting current flow to an inductive D.C. load, comprising first and second switches which are functionally offset, in opening sequence, by a predetermined switching interval; during the switching interval, a like level of energy of polarity opposite to the energy stored in the magnetic field of the load is transferred to a capacitor connected in parallel with the first switch, whereupon both energy charges are simultaneously discharged into and thermally dissipated in a resistance connected in parallel with the capacitor. The switching interval corresponds to one-fourth cycle of the resonance frequency of the resonant circuit formed by the capacitor and the inductive load plus the RC and L/R time functions of the circuit; the resistance is selected, relative to the capacitor and the load inductance, to preclude oscillation of the load current during the time interval between the opening of the first and second switches. The capacitance is selected relative to the load inductance, to fix and limit the maximum voltages occurring in the course of the switching interval.
Inventors
- 👤 J Oswald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:03
CPC Classifications
H; H01; H01H; H01H33/00; H01H33/02; H01H33/59; H01H33/596
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
289 words
A non-oscillating, arcless interruptive control arrangement for an electric circuit comprising a direct-current power supply serving an inductive load: said interruptive control arrangement comprising a capacitance connected into the circuit in series relation with the said inductive load, a first closed switch means connected, in shunt relation, to the said capacitance and in series relation with the said inductive load, a second closed switch means connected serially between the said first closed switch means and the said direct-current power supply, a first resistance means connected, in shunt relation, to the said capacitance and the said first closed switch means; said first closed switch means operable to open and insert into the circuit capacitive reactance of the said capacitance to counter-act the inductive reaCtance of the inductive load to effect an interval of substantially zero-impedance and therefore substantially zero voltage-drop across the contacts of the said first switch means and to insert the said first resistance means into the circuit; the said first resistance means being dimensioned to provide that the inherent RC time character of the said capacitance and the said first resistance means is at least minimally lesser than the inherent L/R time character of the said inductive load and the said first resistance means to thus provide that the capacitance may not return energy to the inductive load subsequent to the initial voltage charge to the said capacitance; said second closed switch means operable to open, subject to suitable delay means and predetermined time interval, to interrupt the circuit subsequent to substantially complete and simultaneous discharge of the stored energy of the said capacitance and the said inductive load and upon reduction and stabilization of the load current to level prescribed by the said first resistance means.
Claim 2
Dependent Claim
289 words
A non-oscillating, arcless interruptive control arrangement for an electric circuit comprising a direct-current power supply serving an inductive load: said interruptive control arrangement comprising a capacitance connected into the circuit in series relation with the said inductive load, a first closed switch means connected, in shunt relation, to the said capacitance and in series relation with the said inductive load, a second closed switch means connected serially between the said first closed switch means and the said direct-current power supply, a first resistance means connected, in shunt relation, to the said capacitance and the said first closed switch means; said first closed switch means operable to open and insert into the circuit capacitive reactance of the said capacitance to counter-act the inductive reaCtance of the inductive load to effect an interval of substantially zero-impedance and therefore substantially zero voltage-drop across the contacts of the said first switch means and to insert the said first resistance means into the circuit; the said first resistance means being dimensioned to provide that the inherent RC time character of the said capacitance and the said first resistance means is at least minimally lesser than the inherent L/R time character of the said inductive load and the said first resistance means to thus provide that the capacitance may not return energy to the inductive load subsequent to the initial voltage charge to the said capacitance; said second closed switch means operable to open, subject to suitable delay means and predetermined time interval, to interrupt the circuit subsequent to substantially complete and simultaneous discharge of the stored energy of the said capacitance and the said inductive load and upon reduction and stabilization of the load current to level prescribed by the said first resistance means.
Claim 3
Dependent Claim
45 words
In a non-oscillating, arcless interruptive control arrangement according to claim 1, further providing an over-current protective device connected between the said first closed switch means and a common junction of the said capacitance, the said first resistance means and the said second closed switch means.
Claim 4
Dependent Claim
43 words
In a non-oscillating, arcless interruptive control arrangement according to claim 1, further providing an over-current protective device connected between the said first closed switch means and a common junction of the said capacitance, the said first resistance means and the said inductive load.
Claim 5
Dependent Claim
70 words
In a non-oscillating, arcless interruptive control arrangement according to claim 1, further providing a parallel combination of a second resistance means and a uni-directionally conductive device, said combination connected between a common junction of the said capacitance and said first resistance means and the common junction of the said first closed switch means and the said inductive load, said uni-directionally conductive device forward-biased in the direction of normal load-current flow.
Claim 6
Dependent Claim
61 words
In a non-oscillating, arcless interruptive control arrangement according to claim 1, further providing a parallel combination of a second resistance means and a uni-directionally conductive device, said combination connected between a common junction of the said capacitance and said first resistance means, and the said second closed switch mans, sai uni-directionally conductive device forward-biased in the direction of normal load-current flow.
Claim 7
Dependent Claim
249 words
A non-oscillating arcless interruptive control arrangement for an electric circuit comprising a direct-current power supply serving an inductive load: said interruptive control arrangement comprising a uni-directionally conductive device connected into the circuit in series relation with the said inductive load and forward-biased in the direction of normal load-current flow, a capacitance connected into the circuit in series relation with the said uni-directionally conductive device and the said inductive load, a first closed switch means, connected, in shunt relation, to the said capacitance, a second closed switch means connected serially between the said first closed switch means and the direct-current power supply, a resistance means connected, in shunt relation, to the said capacitance and the said first closed switch means; said first closed switch means operable to open and insert into the circuit capacitive reactance of the said capacitance to counter-act the inductive reactance of the said inductive load to effect an interval of substantially zero impedance and, therefore, substantially zero-voltage drop across the contacts of the said first switch means and to insert the said resistance means into the circuit, the said resistance means being dimensioned that the initial voltage charge into the said capacitance may not exceed the inverse-voLtage limitation of the said uni-directionally conductive device; said second closed switch means operable to open, subject to suitable delay means and predetermined time interval, to interrupt the circuit subsequent to reduction and stabilization of the load-current thru the said inductive load to level prescribed by the said resistance means.
Claim 8
Dependent Claim
249 words
A non-oscillating arcless interruptive control arrangement for an electric circuit comprising a direct-current power supply serving an inductive load: said interruptive control arrangement comprising a uni-directionally conductive device connected into the circuit in series relation with the said inductive load and forward-biased in the direction of normal load-current flow, a capacitance connected into the circuit in series relation with the said uni-directionally conductive device and the said inductive load, a first closed switch means, connected, in shunt relation, to the said capacitance, a second closed switch means connected serially between the said first closed switch means and the direct-current power supply, a resistance means connected, in shunt relation, to the said capacitance and the said first closed switch means; said first closed switch means operable to open and insert into the circuit capacitive reactance of the said capacitance to counter-act the inductive reactance of the said inductive load to effect an interval of substantially zero impedance and, therefore, substantially zero-voltage drop across the contacts of the said first switch means and to insert the said resistance means into the circuit, the said resistance means being dimensioned that the initial voltage charge into the said capacitance may not exceed the inverse-voLtage limitation of the said uni-directionally conductive device; said second closed switch means operable to open, subject to suitable delay means and predetermined time interval, to interrupt the circuit subsequent to reduction and stabilization of the load-current thru the said inductive load to level prescribed by the said resistance means.
Claim 9
Dependent Claim
38 words
In a non-oscillating, arcless interruptive control arrangement according to claim 6 and further providing that the said uni-directionally conductive device may be comprised of a plurality of rectifier diodes serially connected and provided with compatible inverse-voltage protective means.
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) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |