US3681613A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Timing circuit
Assignee: Berkey Photo Inc
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Filing: 1970-05-28
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Granted: 1972-08-01
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Expires: 1990-05-28
Abstract
Abstract Timing circuit including a R-C circuit connected in parallel with a voltage divider across a direct current supply. Voltage sensing means is connected between the midpoints of the R-C circuit and the voltage divider. Upon the occurrence of equal voltages at these points the timed interval is completed. The circuit is operative under variations in magnitude of the supply voltage.
Inventors
- 👤 Robert A Flieder
- 👤 Louis L Weisglass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:21
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/28; H03K17/292; H03K17/51; H03K17/56; H03K17/72; H03K17/725
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
170 words
A timing circuit comprising a source of direct current, capacitor means, resistor means connected in series with said capacitor means and foRming therewith a series circuit, said series circuit forming a first reference point between said resistor means and said capacitor means, voltage divider means having a tap and connected in parallel with said series circuit across said source of direct current, said voltage divider means forming at said tap a second reference point, control means responsive to substantially equal voltages at said reference points and connected between said reference points, and starting means for starting a timing sequence; said starting means including closeable connector means connected across said capacitor means for discharging said capacitor means when closed, switch means actuated by said control means responsive to substantially equal voltages between said reference points for closing said connector means when actuated and for opening said connector means when unactuated, and manually operable bypass means for closing and then opening said connector means regardless of the actuation of said switch means.
Claim 2
Dependent Claim
170 words
A timing circuit comprising a source of direct current, capacitor means, resistor means connected in series with said capacitor means and foRming therewith a series circuit, said series circuit forming a first reference point between said resistor means and said capacitor means, voltage divider means having a tap and connected in parallel with said series circuit across said source of direct current, said voltage divider means forming at said tap a second reference point, control means responsive to substantially equal voltages at said reference points and connected between said reference points, and starting means for starting a timing sequence; said starting means including closeable connector means connected across said capacitor means for discharging said capacitor means when closed, switch means actuated by said control means responsive to substantially equal voltages between said reference points for closing said connector means when actuated and for opening said connector means when unactuated, and manually operable bypass means for closing and then opening said connector means regardless of the actuation of said switch means.
Claim 3
Dependent Claim
26 words
A timing circuit as in claim 1, further comprising network means having a line, said connector means including regulator means for opening and closing the line.
Claim 4
Dependent Claim
24 words
A timing circuit as in claim 1, wherein said connector means comprises a relay having a normally open contact connected across said capacitor means.
Claim 5
Dependent Claim
22 words
A timing circuit as in claim 3, wherein said relay includes a normally closed contact connected in a line to a load.
Claim 6
Dependent Claim
22 words
A timing circuit as in claim 3, wherein said switch means includes a bistable device which when actuated remains actuated until commuted.
Claim 7
Dependent Claim
36 words
A timing circuit as in claim 3, wherein said bypass means is connected to commute said switch means when said bypass means is closed and to release said switch means when said bypass means is open.
Claim 8
Dependent Claim
36 words
A timing circuit as in claim 1, wherein said connector means includes a relay having a coil connected in series with said switch means, said relay having a normally open contact connected across said capacitor means.
Claim 9
Dependent Claim
23 words
A timing circuit as in claim 7, wherein said relay further includes normally closed contact means connected in a line to a load.
Claim 10
Dependent Claim
22 words
A timing circuit as in claim 7, wherein said switch means includes a bistable device which when actuated remains actuated until commuted.
Claim 11
Dependent Claim
36 words
A timing circuit as in claim 7, wherein said bypass means is connected to commute said switch means when said bypass means is closed and to release said switch means when said bypass means is open.
Claim 12
Dependent Claim
26 words
A timing circuit as in claim 10, wherein said switch means includes thyristor means and said bypass means includes a contactor connected across said thyristor means.
Claim 13
Dependent Claim
19 words
A timing circuit as in claim 11, wherein said actuator means includes a differentiating circuit for pulsing said thyristor.
Claim 14
Dependent Claim
33 words
A timing circuit as in claim 1, further comprising switching means for turning said source on and off, and actuator means responsive to said source being turned on for actuating said switch means.
Claim 15
Dependent Claim
22 words
A timing circuit as in claim 13, wherein said switch means includes a bistable device which when actuated remains actuated until commuted.
Claim 16
Dependent Claim
21 words
A timing circuit as in claim 14, wherein said bypass means is connected to commute said switch means when turned on.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |