US3758877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power supply for carbon dioxide lasers
Assignee: Individual
•
Filing: 1972-05-09
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Granted: 1973-09-11
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Expires: 1992-05-09
Abstract
Abstract In a power supply for a CO2 laser tube including an A.C. source, a rectifier and a filter, an inductance connected in front of the rectifier provides a non-dissapative positive resistance effect for cancelling the negative differential resistance exhibited by the tube at frequencies below about 2kHz. The inductance replaces the ballast resistors usually used for the same purposes and provides a resultant increase in system efficiency. The frequency of the A.C. source is preferably in excess of 25 kHz thus taking advantage of the low amplitude and frequency fluctuations at high frequencies and enabling the use of a low value filter capacitor.
Inventors
- 👤 J Fletcher
- 👤 G Schiffner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:46
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/09; H01S3/097; Y; Y10; Y10S; Y10S315/00; Y10S315/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
119 words
In combination, a d.c. excited continuous wave CO2 gas laser discharge tube exhibiting a positive differential resistance at frequencies above a predetermined frequency and exhibiting a negative differential resistance at frequencies below said predetermined frequency, and a power supply for said tube comprising an a.c. voltage source for producing a supply voltage having a frequency greater than said predetermined frequency, a rectifier coupled to the output of said a.c. voltage source for producing a rectified d.c. output; a filter capacitor connected to said rectifier and in parallel with said discharge tube for filtering the output of the rectifier; and an inductance connected in front of said rectifier for stabilizing The output resistance of the power supply at low frequencies.
Claim 2
Dependent Claim
119 words
In combination, a d.c. excited continuous wave CO2 gas laser discharge tube exhibiting a positive differential resistance at frequencies above a predetermined frequency and exhibiting a negative differential resistance at frequencies below said predetermined frequency, and a power supply for said tube comprising an a.c. voltage source for producing a supply voltage having a frequency greater than said predetermined frequency, a rectifier coupled to the output of said a.c. voltage source for producing a rectified d.c. output; a filter capacitor connected to said rectifier and in parallel with said discharge tube for filtering the output of the rectifier; and an inductance connected in front of said rectifier for stabilizing The output resistance of the power supply at low frequencies.
Claim 3
Dependent Claim
20 words
The combination claimed in claim 1 wherein said a.c. source produces a voltage having a frequency in excess of 2kHz.
Claim 4
Dependent Claim
20 words
The combination claimed in claim 1 wherein said a.c. source produces a voltage having a frequency in excess of 25kHz.
Claim 5
Dependent Claim
30 words
The combination claimed in claim 2 wherein said power supply further comprises a transformer connected to said a.c. source, said inductance being connected on the primary side of said transformer.
Claim 6
Dependent Claim
30 words
The combination claimed in claim 2 wherein said power supply further comprises a transformer, said inductance being connected on the secondary side of said transformer in front of said rectifier.
Claim 7
Dependent Claim
121 words
In a system comprising a d.c. excited continuous wave CO2 laser tube exhibiting a positive differential resistance at frequencies above a predetermined frequency and exhibiting a negative differential resistance at frequencies below a predetermined frequency, and a power supply for said tube comprising an a.c. voltage source, a rectifier connected to said source and a filter for smoothing the output of said rectifier, the improvement comprising said a.c. source being a high frequency source for producing a voltage having a frequency above said predetermined frequency, and further including an inductance connected in series between said source and said rectifier for providing a non-dissapative positive resistance effect to cancel the negative differential resistance exhibited by said CO2 laser tube at low frequencies.
Claim 8
Dependent Claim
121 words
In a system comprising a d.c. excited continuous wave CO2 laser tube exhibiting a positive differential resistance at frequencies above a predetermined frequency and exhibiting a negative differential resistance at frequencies below a predetermined frequency, and a power supply for said tube comprising an a.c. voltage source, a rectifier connected to said source and a filter for smoothing the output of said rectifier, the improvement comprising said a.c. source being a high frequency source for producing a voltage having a frequency above said predetermined frequency, and further including an inductance connected in series between said source and said rectifier for providing a non-dissapative positive resistance effect to cancel the negative differential resistance exhibited by said CO2 laser tube at low frequencies.
Claim 9
Dependent Claim
25 words
A system as claimed in claim 6 wherein said high frequency a.c. source produces a supply voltage having a frequency in excess of 25 kHz.
Claim 10
Dependent Claim
40 words
A system as claimed in claim 7 wherein said power supply further comprises a transformer connected to said source and said inductance comprises an inductive element connected on the primary side of said transformer between said transformer and said source.
Claim 11
Dependent Claim
20 words
A system as claimed in claim 7 wherein said inductance comprises an inductive element connected in front of said rectifier.
Claim 12
Dependent Claim
27 words
A system as claimed in claim 9 wherein said filter comprises a filter capacitor connected to the output of said rectifier in parallel with said laser tube.
References Cited (Backward Citations)
US3356891A
Cited
US3688123A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |