US3794857A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulsating timer
Assignee: Individual
•
Filing: 1972-02-07
•
Granted: 1974-02-26
•
Expires: 1992-02-07
Abstract
Abstract A pulsating timer consists of two timers - first one produces repeatedly a short pulse at the end of its timing period, the second one produces a pulse at the end of the desired time period. Pulses from the first timer are fed through a diode and a resistor into a storage capacitor. Since the storage capacitor is charged with current pulses at time intervals as first timer dictates, many pulses are needed to charge it sufficiently to trigger a voltage sensing means. Said resistor, storage capacitor, and voltage sensing means form said second timer which will produce its first pulse after a long time interval and in synchronism with said first timer. Both timers are temperature compensated to assure longer and more accurate time intervals.
Inventors
- 👤 S Milovancevic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:45
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/28; H03K17/292
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
518 words
A pulsating timer for producing accurate, adjustable time intervals over wide ambient temperature range, immune to false triggering, and comprising: a DC power source having negative terminal connected to a common lead, and a positive terminal connected to the common terminal of a power switch, whose normally open terminal is connected to a supply lead, a series connection of two resistors, one resistor, being variable to adjust said time intervals, connected to said supply lead and having its remaining end connected to a first current limiting resistor whose other end is connected to one plate of a first storage capacitor having remaining plate connected to said common lead, a first programmable unijunction transistor (PUT) having an anode, anode-gate, and a cathode electrode, said anode electrode being connected to the interconnection of said first current limiting resistor and said first storage capacitor to sense the potential across it, while said cathode electrode is connected to a first cathode resistor having its remaining end connected to said common lead, a voltage divider consisting of a first and a second resistor, said first resistor is connected to said common lead, while its other end is connected to said second resistor whose remaining end is connected to said supply lead, first diode having anode electrode connected to the interconnection of said first and said second resistor, its cathode electrode is connected to an anode-gate resistor connected by its other end to said anodegate electrode of said first PUT, a biasing resistor connected to said common lead and having its remaining end connected to the interconnection of said cathode electrode of said first diode, and said anode-gate resistor, for purpose of allowing conduction of the biasing current through said first diode, and forming of the reference potential for said first PUT, second diode connected by its anode electrode to said interconnection of said first PUT and said first cathode resistor, its cathode electrode is connected to a second current limiting resistor having its other end connected to one plate of a second storage capacitor having remaining plate connected to said common lead, second programmable unijunction transistor (PUT), used as the voltage sensing means across said second storage capacitor, having anode, anode-gate, and cathode electrode, said anode electrode being connected to the interconnection of said second current limiting resistor and said second storage capacitor, to sense the potential across the last one, anode-gate electrode being connected to the interconnection of said anode-gate resistor, said biasing resistor and said cathode electrode of said first diode, to receive said reference potential and enable said second PUT to trigger in synchronism with said first PUT, and also to receive the compensating voltage for its anode - anode-gate junction voltage variance due to ambient temperature, cathode electrode of said second PUT is connected to one end of the second cathode resistor, having its remaining end connected to said common lead, used to develop a positive going voltage pulse due to discharge current from said second storage capacitor through said second PUT, at the end of the timing interval, said positive going voltage pulse used to control other devices.
Claim 2
Dependent Claim
518 words
A pulsating timer for producing accurate, adjustable time intervals over wide ambient temperature range, immune to false triggering, and comprising: a DC power source having negative terminal connected to a common lead, and a positive terminal connected to the common terminal of a power switch, whose normally open terminal is connected to a supply lead, a series connection of two resistors, one resistor, being variable to adjust said time intervals, connected to said supply lead and having its remaining end connected to a first current limiting resistor whose other end is connected to one plate of a first storage capacitor having remaining plate connected to said common lead, a first programmable unijunction transistor (PUT) having an anode, anode-gate, and a cathode electrode, said anode electrode being connected to the interconnection of said first current limiting resistor and said first storage capacitor to sense the potential across it, while said cathode electrode is connected to a first cathode resistor having its remaining end connected to said common lead, a voltage divider consisting of a first and a second resistor, said first resistor is connected to said common lead, while its other end is connected to said second resistor whose remaining end is connected to said supply lead, first diode having anode electrode connected to the interconnection of said first and said second resistor, its cathode electrode is connected to an anode-gate resistor connected by its other end to said anodegate electrode of said first PUT, a biasing resistor connected to said common lead and having its remaining end connected to the interconnection of said cathode electrode of said first diode, and said anode-gate resistor, for purpose of allowing conduction of the biasing current through said first diode, and forming of the reference potential for said first PUT, second diode connected by its anode electrode to said interconnection of said first PUT and said first cathode resistor, its cathode electrode is connected to a second current limiting resistor having its other end connected to one plate of a second storage capacitor having remaining plate connected to said common lead, second programmable unijunction transistor (PUT), used as the voltage sensing means across said second storage capacitor, having anode, anode-gate, and cathode electrode, said anode electrode being connected to the interconnection of said second current limiting resistor and said second storage capacitor, to sense the potential across the last one, anode-gate electrode being connected to the interconnection of said anode-gate resistor, said biasing resistor and said cathode electrode of said first diode, to receive said reference potential and enable said second PUT to trigger in synchronism with said first PUT, and also to receive the compensating voltage for its anode - anode-gate junction voltage variance due to ambient temperature, cathode electrode of said second PUT is connected to one end of the second cathode resistor, having its remaining end connected to said common lead, used to develop a positive going voltage pulse due to discharge current from said second storage capacitor through said second PUT, at the end of the timing interval, said positive going voltage pulse used to control other devices.
Claim 3
Dependent Claim
122 words
A pulsating timer as claimed in 1, and further including a silicon controlled rectifier (SCR) having anode, cathode, and gate electrode in which said gate electrode is connected to the interconnection of said second cathode electrode and said second cathode resistor, said SCR cathode electrode is connected to an SCR cathode resistor whose other end is connected to said common lead and used to develop a control voltage once SCR is conductive, SCR anode resistor connected to said SCR anode electrode and having its remaining end connected to said supply lead in order to limit the current through said SCR (along with said SCR cathode resistor) and develop a voltage drop, while said SCR is conductive, for purpose of controlling other devices.
References Cited (Backward Citations)
CA792905A
Cited
US2873388A
Cited
US3031583A
Cited
US3340460A
Cited
US3158757A
Cited
US3204153A
Cited
GB1120111A
Cited
US3378698A
Cited
US3456554A
Cited
US3636379A
Cited
US3700914A
Cited
US3706890A
Cited
US3705417A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |