US3919622A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Commutation chopper circuit with independent trigger
Assignee: Kansas State University
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Filing: 1974-03-27
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Granted: 1975-11-11
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Expires: 1994-03-27
Abstract
Abstract A commutation chopper circuit is disclosed for supplying an alternating voltage from a constant voltage source, such as a battery, to a motor or the like. The battery is coupled to the motor by means of a controlled switch, such as a silicon control rectifier or thyristor. A secondary cutoff loop circuit is provided across the primary switch, including a secondary switch and a capacitor, the capacitor being connected in the negative terminal of the primary switch. When the primary switch is conducting, an independent source charges the capacitor to a polarity such that when the secondary switch conducts, the capacitor will be applied across the terminals of the primary switch to reverse bias it; and a load current will be shunted through the secondary switch and the capacitor in series. After the primary switch is cut off, the load current diminishes to zero, and the secondary switch is also non-conducting, and the cycle may be repeated.
Inventors
- 👤 Nema Mudhafar A Al
- 👤 Wellington W Koepsel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:26
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/02; H02M3/04; H02M3/10; H02M3/125; H02M3/135; Y; Y10; Y10S; Y10S388/00; Y10S388/907; Y10S388/917
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
185 words
A commutation chopper system for supplying energy from a constant voltage source to a load comprising: a primary gatable switch connected between said source and said load; a secondary gatable switch and a commutation capacitor connected in series across said first gatable switch; an independent source of voltage and unidirectional current conducting means connected in series circuit between said commutation capacitor and the junction between said first and second gatable switches and of a polarity so as to charge said commutation capacitor when said first gatable switch conducts; and trigger circuit means for applying a first trigger pulse to said first gatable switch to cause the same to conduct and for applying a second trigger pulse to said second gatable switch a predetermined time after said first switch conducts; whereby when said first switch conducts, said commutation capacitor is charged directly by said independent voltage source less only the voltage drops across said conducting first switch and said unidirectional current conducting means, and when said second switch conducts, said commutation capacitor is connected across said first gatable switch in a polarity to shut it off.
Claim 2
Dependent Claim
185 words
A commutation chopper system for supplying energy from a constant voltage source to a load comprising: a primary gatable switch connected between said source and said load; a secondary gatable switch and a commutation capacitor connected in series across said first gatable switch; an independent source of voltage and unidirectional current conducting means connected in series circuit between said commutation capacitor and the junction between said first and second gatable switches and of a polarity so as to charge said commutation capacitor when said first gatable switch conducts; and trigger circuit means for applying a first trigger pulse to said first gatable switch to cause the same to conduct and for applying a second trigger pulse to said second gatable switch a predetermined time after said first switch conducts; whereby when said first switch conducts, said commutation capacitor is charged directly by said independent voltage source less only the voltage drops across said conducting first switch and said unidirectional current conducting means, and when said second switch conducts, said commutation capacitor is connected across said first gatable switch in a polarity to shut it off.
Claim 3
Dependent Claim
16 words
The system of claim 1 wherein each of said gatable switches is a silicon control rectifier.
Claim 4
Dependent Claim
58 words
The system of claim 1 wherein said independent voltage source comprises transformer means and a diode connected in series between said commutation capacitor and the junction between said first and second switches and said voltage source for continuously supplying a voltage to charge said commutation capacitor when said first switch is conducting and said second switch is non-conducting.
Claim 5
Dependent Claim
57 words
The system of claim 3 wherein said independent voltage source further comprises a saturable reactor having first, second and third primary windings; a first switch coupled to said first winding; a second switch coupled to said second winding, and feedback circuitry coupled to said third primary winding for alternately causing said first and second switches to conduct.
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) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |