Patent US4988889A successfully refreshed from Google Patents.
US4988889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power source for emergency lighting systems
Assignee: SELF-POWERED LIGHTING Inc
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Filing: 1989-07-03
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Granted: 1991-01-29
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Expires: 2009-07-03
Abstract
Abstract A buck/boost converter is driven by a high frequency dc-to-dc flyback converter to provide substantially constant output power, independent of the output voltage, to an inductor to provide current to a load having a v-i characteristic that is suitable for use with a current power source, such as a plurality of parallely-connected LEDs. The flyback converter repetitively generates a battery-simulated output voltage that is current-limited and which may be used to charge a battery as well as to provide power to the buck/boost converter. The buck/boost converter includes a switching circuit for repetitively transferring current to the load and a current sensor circuit operating in conjunction with the switching circuit to change the state of the buck/boost converter to repetitively open the switching means and initiate release of the current to the load.
Inventors
- 👤 George W. Oughton, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:20
CPC Classifications
H; H02; H02J; H02J9/00; H02J9/04; H02J9/06; H02J9/062; H02J9/065; H05; H05B; H05B45/00; H05B45/30; H05B45/37; H05B45/3725; H05B45/385; H05B45/40; H05B45/44; H05B45/46
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
141 words
In a power source for a battery operated system, the combination comprising: dc power source means for providing a battery-simulating voltage a high frequency dc-to-dc input converter means for supplying power to said dc power source means; a substantially constant current demand load; second converter means for repetitively transferring current from said dc power source means to said load and including an inductor means and a capacitor parallely connected to said load and a diode electrically connecting said inductor and said capacitor, switching means for alternately storing and releasing current from said inductor means to said load and connected in series with said inductor; and battery means in parallel with said dc power source means for maintaining the voltage on said dc power source means and operating said second converter means in the absence of power by said input converter means.
Claim 2
Dependent Claim
141 words
In a power source for a battery operated system, the combination comprising: dc power source means for providing a battery-simulating voltage a high frequency dc-to-dc input converter means for supplying power to said dc power source means; a substantially constant current demand load; second converter means for repetitively transferring current from said dc power source means to said load and including an inductor means and a capacitor parallely connected to said load and a diode electrically connecting said inductor and said capacitor, switching means for alternately storing and releasing current from said inductor means to said load and connected in series with said inductor; and battery means in parallel with said dc power source means for maintaining the voltage on said dc power source means and operating said second converter means in the absence of power by said input converter means.
Claim 3
Dependent Claim
73 words
The power source as claimed in claim 1, wherein the dc power source means includes a capacitor connected across said second converter means and said high frequency dc-to-dc input converter means includes a transformer having a primary winding connected across the input of said high frequency dc-to-dc input converter means and a secondary winding connected across said capacitor for transferring current to charge said capacitor and provide power to said second converter means.
Claim 4
Dependent Claim
18 words
The power source as claimed in claim 1, wherein said second converter means operates as an oscillator means.
Claim 5
Dependent Claim
38 words
The power source as claimed in claim 1, wherein said second converter means further includes current sensor means operative with said switching means closed to change the state of said second converter means to open said switching means.
Claim 6
Dependent Claim
16 words
The power source as claimed in claim 1, wherein said load includes a plurality of LEDs.
Claim 7
Dependent Claim
17 words
The power source as claimed in claim 5, wherein said plurality of LEDs are connected in parallel.
Claim 8
Dependent Claim
65 words
The power source as claimed in claim 1, wherein said battery means includes second normally closed switching means interconnecting said battery means in parallel with said dc power source means, and the combination further comprising battery low voltage drop-out means sensing the voltage of said battery means and opening said second switching means when the voltage of said battery means falls below a predetermined voltage.
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) | 1994-01-28 | 1994-07-30 | 1995-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-28 | 1998-07-30 | 1999-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-28 | 2002-07-30 | 2003-01-29 | $7700.00 | Window Closed / Lapsed |