US3858087A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit for prolonging the life of fluorescent lamps
Assignee: CML Macarr Inc
•
Filing: 1973-06-19
•
Granted: 1974-12-31
•
Expires: 1993-06-19
Abstract
Abstract A circuit for extending the life of fluorescent tubes driven from a power source subject to interruptions, which includes a uni-directional conducting elements inserted in the line from the power source, a separately powered power source of substantially lower voltage than the main power source but of sufficient voltage to maintain the fluorescent tube in conduction, a second uni-directional device connected between the secondary power source and the common junction of the first uni-directional device and the load. Further, the circuit may include a voltage sensor to determine whether or not the power is present on the primary power source, a timer to time the length of time during which power is missing, and means of disconnecting the secondary power source when such time is excessive.
Inventors
- 👤 H Tomsky
- 👤 H Parke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:47
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/46
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
197 words
A circuit for prolonging the life of fluorescent lamps operated from a main source of direct current operating potential subject to random, unwanted interruption, comprising input means adapted to be connected at an input terminal with the source; output means adapted to be connected at an output terminal with the lamps; First unidirectional means connected at one end to said input terminal and at the other end to said output terminal for supplying said lamps with operating potential from said main source for normal operation; an auxiliary direct current power source having a voltage less than that of the main source but greater than the extinction voltage of the lamps; and second unidirectional means connected at one end of said auxiliary source and at the other end to said output terminal, said second unidirectional means cooperating with said first unidirectional means for supplying full operating potential to the lamps when the main source is operative and for supplying said lesser operating potential to the lamps from said auxiliary source in response to the occurrence of a random, unwanted interruption of said main source whereby the lamps are precluded from becoming extinguished upon interruption of the main source.
Claim 2
Dependent Claim
197 words
A circuit for prolonging the life of fluorescent lamps operated from a main source of direct current operating potential subject to random, unwanted interruption, comprising input means adapted to be connected at an input terminal with the source; output means adapted to be connected at an output terminal with the lamps; First unidirectional means connected at one end to said input terminal and at the other end to said output terminal for supplying said lamps with operating potential from said main source for normal operation; an auxiliary direct current power source having a voltage less than that of the main source but greater than the extinction voltage of the lamps; and second unidirectional means connected at one end of said auxiliary source and at the other end to said output terminal, said second unidirectional means cooperating with said first unidirectional means for supplying full operating potential to the lamps when the main source is operative and for supplying said lesser operating potential to the lamps from said auxiliary source in response to the occurrence of a random, unwanted interruption of said main source whereby the lamps are precluded from becoming extinguished upon interruption of the main source.
Claim 3
Dependent Claim
39 words
The invention according to claim 1 further including voltage sensing means connected between said input means and said auxiliary direct power source and responsive to interruptions in operating potential supplied by the main source to actuate said auxiliary source.
Claim 4
Dependent Claim
39 words
The invention according to claim 2 further including timing means coupled with said voltage sensing means such that said voltage sensing means deactuates said auxiliary source after a predetermined time delay has elapsed following interruption of the main source.
Claim 5
Dependent Claim
15 words
The invention according to claim 3 wherein said timing means includes a capacitance discharge network.
Claim 6
Dependent Claim
32 words
The invention according to claim 4 wherein said voltage sensing means includes a monostable transistor network responsive to said timing means to control said auxiliary source after said time delay has elapsed.
Claim 7
Dependent Claim
20 words
The invention according to claim 2 wherein said voltage sensing means includes a plurality of transistor switches coupled in series.
References Cited (Backward Citations)
US825847A
Cited
US3059146A
Cited
US3262018A
Cited
US3324304A
Cited
US3280366A
Cited
US3566186A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |