US3833824A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiation hardened flip-flop
Assignee: United States Department of the Army
•
Filing: 1972-09-06
•
Granted: 1974-09-03
•
Expires: 1992-09-06
Abstract
Abstract Two inductors are inserted in series with the controlling transistors'' paths to ground, and diodes shunt the inductors. Further diodes are back connected between the base circuits of the controlling transistors and ground. A third inductor shunted by a diode is connected between the base circuits of the toggle transistors and ground. The time constants of these circuits are selected such that the flip-flop returns to its initial state after a high radiation level has subsided due to the stored energy in one of the inductors.
Inventors
- 👤 K Parks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:54
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/26; H03K3/28; H03K3/281; H03K3/286; H03K3/287; H03K3/01; H03K3/011; H03L; H03L1/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
423 words
In a flip-flop having first and second transistors which control the state of the flip-flop; the improvement comprising first and second inductors; first and second diodes connected respectively in shunt with said first and second inductors to form first and second parallel combinations; the first and second parallel combinations being connected respectively in series with said first and second transistors and having predetermined time constants so that when the flip-flop circuit is subjected to a high level radiation it will retain its initial state after the radiation has subsided when the time constants of the parallel combinations are greater than the length of the radiation; a toggling circuit; third inductor and third diode connected in shunt to form a third parallel combination; said third parallel combination being connected in said toggling circuit so that when a toggle signal is interrupted due to a short lived high radiation, the signal will continue when the time constant of the third parallel combination is greater than the length of the radiation; first and second resistors having first and second sides; voltage input connections; said first sides of each of said resistors being connected to one of said voltage input connections; the second side of said first and second resistors being connected respectively to one side of said first and second transistors; another side of said first and second transistors being connected respectively through said first and second parallel combinations to a second one of said voltage connections; crossover connections comprising third and fourth resistors; said third resistor being connected between a control input of said first transistor and the second side of said second resistor; said fourth resistor being connected between a control input of said second transistor and the second side of said first resistor; fourth and fifth diodes connected respectively between the control inputs of said first and second transistors and said second one of the voltage connections; said fourth and fifth diodes being connected such that they oppose normal current flow; first and second output terminals of the flip-flop connected respectively to the second side of said first and second resistors; said toggling circuit further comprising third and fourth transistors connected respectively between the respective crossover connections and respective junctions between said first and second transistors and said first and second inductors; a toggle pulse input connected to the control inputs of said third and fourth transistors; and said third combination being connected in parallel between the control inputs of said third and fourth transistors and said second one of said voltage connections.
Claim 2
Dependent Claim
423 words
In a flip-flop having first and second transistors which control the state of the flip-flop; the improvement comprising first and second inductors; first and second diodes connected respectively in shunt with said first and second inductors to form first and second parallel combinations; the first and second parallel combinations being connected respectively in series with said first and second transistors and having predetermined time constants so that when the flip-flop circuit is subjected to a high level radiation it will retain its initial state after the radiation has subsided when the time constants of the parallel combinations are greater than the length of the radiation; a toggling circuit; third inductor and third diode connected in shunt to form a third parallel combination; said third parallel combination being connected in said toggling circuit so that when a toggle signal is interrupted due to a short lived high radiation, the signal will continue when the time constant of the third parallel combination is greater than the length of the radiation; first and second resistors having first and second sides; voltage input connections; said first sides of each of said resistors being connected to one of said voltage input connections; the second side of said first and second resistors being connected respectively to one side of said first and second transistors; another side of said first and second transistors being connected respectively through said first and second parallel combinations to a second one of said voltage connections; crossover connections comprising third and fourth resistors; said third resistor being connected between a control input of said first transistor and the second side of said second resistor; said fourth resistor being connected between a control input of said second transistor and the second side of said first resistor; fourth and fifth diodes connected respectively between the control inputs of said first and second transistors and said second one of the voltage connections; said fourth and fifth diodes being connected such that they oppose normal current flow; first and second output terminals of the flip-flop connected respectively to the second side of said first and second resistors; said toggling circuit further comprising third and fourth transistors connected respectively between the respective crossover connections and respective junctions between said first and second transistors and said first and second inductors; a toggle pulse input connected to the control inputs of said third and fourth transistors; and said third combination being connected in parallel between the control inputs of said third and fourth transistors and said second one of said voltage connections.
References Cited (Backward Citations)
US3731119A
Cited
US3700930A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-02 | 1978-03-04 | 1978-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-02 | 1982-03-04 | 1982-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-02 | 1986-03-04 | 1986-09-03 | $7700.00 | Window Closed / Lapsed |