US4749934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intrinsically safe battery circuit
Assignee: BankBoston NA
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Filing: 1986-11-07
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Granted: 1988-06-07
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Expires: 2006-11-07
Abstract
Abstract An intrinsically safe battery circuit for connection between a battery and a load, such as a hand held transceiver, referred to as "HT's". The circuit includes a minor current path through a switching transistor and a major current path through a SCR. The circuit is a hybrid circuit which includes an integrated circuit timer which provides a delay in establishing the major current path subsequent to the minor current path being established, and mounts on a small printed circuit board.
Inventors
- 👤 Richard Alexander
- 👤 Dennis Kindschuh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:55
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/60; H02J7/663; Y; Y10; Y10S; Y10S320/00; Y10S320/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
128 words
An safe battery output circuit comprising: a. battery means b. circuit means for connecting said battery means to a load means; c. said circuit means for connecting including a minor current path means passing current from said battery means to said load means, timing circuit means, and switch means, having a control gate means, for providing a low impedance path from said battery to a load; and, d. said timing circuit means including an RC network with rapid decay being connected to said minor current path means to develop an output signal after a predetermined time interval triggering said control gate means for switching in a major current path of low resistance through said switch means between said battery means and load means after said predetermined time interval.
Claim 2
Dependent Claim
128 words
An safe battery output circuit comprising: a. battery means b. circuit means for connecting said battery means to a load means; c. said circuit means for connecting including a minor current path means passing current from said battery means to said load means, timing circuit means, and switch means, having a control gate means, for providing a low impedance path from said battery to a load; and, d. said timing circuit means including an RC network with rapid decay being connected to said minor current path means to develop an output signal after a predetermined time interval triggering said control gate means for switching in a major current path of low resistance through said switch means between said battery means and load means after said predetermined time interval.
Claim 3
Dependent Claim
11 words
Circuit of claim 1 wherein said switching means is an SCR.
Claim 4
Dependent Claim
13 words
Circuit of claim 1 wherein said timing means is a 555 integrated circuit.
Claim 5
Dependent Claim
36 words
Circuit of claim 1 including a diode connected across said resistor of said RC network to provide a reverse current path for rapid discharge of said capacitor of said RC network upon disconnection of a load.
Claim 6
Dependent Claim
16 words
Circuit of claim 1 including a current activated switch connected in series with said battery means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-07 | 1991-12-07 | 1992-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-07 | 1995-12-07 | 1996-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-07 | 1999-12-07 | 2000-06-07 | $7700.00 | Window Closed / Lapsed |