Patent US770600A successfully refreshed from Google Patents.
US3710134A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power supply for alarm system
Assignee: Alarm Device Manufacturing Co
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Filing: 1971-05-10
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Granted: 1973-01-09
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Expires: 1991-05-10
Abstract
Abstract A power supply for alarm systems. Under normal power conditions the disclosed circuit rectifies A.C. house current and provides 6 volt D.C. power to the alarm protective and signal circuits. Rechargeable batteries are disposed in the supply circuit so as to be kept at full potential by a constant trickle charge, and if house current fails the batteries are automatically available to power the alarm system. Intermittent switching and delay means are provided in the circuit and function such that if the batteries are placed under load, as by ringing an alarm bell, the batteries are intermittently removed from the load circuit thereby prolonging their life and the period during which alerting by the alarm system is possible.
Inventors
- 👤 L Guthart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:57
CPC Classifications
H; H02; H02J; H02J9/00; H02J9/04; H02J9/06; H02J9/061
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
144 words
A power supply for a burglar alarm system, comprising in combination: input circuit means connectable to line power at the premises protected by said system; voltage reduction means for reducing the potential of said line power; means for rectifying the reduced potential line current; a set of rechargeable batteries connected to receive constant trickle charging from said rectifying means; output circuit means for powering said alarm system, connectable to receive the outputs of said rechargeable batteries and said rectifying means; and switch operating and delay circuit means connected to sense the potential of said batteries upon said batteries being placed under substantial load by line power failure and subsequent activation of alarm signalling devices, to provide power for intermittent on and off periods, thereby extending the functional life of the powering batteries and the period during which said alarm system may provide battery-powered protection.
Claim 2
Dependent Claim
144 words
A power supply for a burglar alarm system, comprising in combination: input circuit means connectable to line power at the premises protected by said system; voltage reduction means for reducing the potential of said line power; means for rectifying the reduced potential line current; a set of rechargeable batteries connected to receive constant trickle charging from said rectifying means; output circuit means for powering said alarm system, connectable to receive the outputs of said rechargeable batteries and said rectifying means; and switch operating and delay circuit means connected to sense the potential of said batteries upon said batteries being placed under substantial load by line power failure and subsequent activation of alarm signalling devices, to provide power for intermittent on and off periods, thereby extending the functional life of the powering batteries and the period during which said alarm system may provide battery-powered protection.
Claim 3
Dependent Claim
47 words
Apparatus in accordance with claim 1, wherein normally closed switch means are connected between said output circuit means and the outputs of said batteries and said rectifying means, and are opened by said switch means for a delay period upon said potential dropping below a predetermined level.
Claim 4
Dependent Claim
69 words
Apparatus in accordance with claim 2, wherein said switch means is solonoid operated, and said switch operating and delay circuit means includes a first branch connected across the outputs from said batteries and said rectifier means, said branch having in series a normally on transistor switching means and the coil for said solonoid, said transistor switching means being turned off in response said sensed potential drop at said batteries.
Claim 5
Dependent Claim
60 words
Apparatus in accordance with claim 3, wherein said switch operating and delay circuit means further includes a second branch connected in parallel with said first branch for sensing said potential drops, said second branch having a voltage reference diode and resistor in series therewith, voltage drops in said branch being coupled to said transistor switching means to effect said turn-off.
Claim 6
Dependent Claim
30 words
Apparatus in accordance with claim 4, further including RC delay circuit means at said transistor switching means, for delaying turn-on of said switching means for a predetermined period following turn-off.
Claim 7
Dependent Claim
26 words
Apparatus in accordance wIth claim 1 wherein said rectifying means comprises a single diode connected between one side of said transformer means and said rechargeable batteries.
Claim 8
Dependent Claim
14 words
Apparatus in accordance with claim 6, wherein said batteries are of the nickel-cadmium type.
References Cited (Backward Citations)
US3603973A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |