Radiation hardened r-l flip-flop circuit

Claim 1

In a flip-flop circuit having first and second controlled switching means which are controlled by first and second crossover paths; the improvement comprising first and second inductors connected respectively in the first and second cross-over paths 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; a parallel combination of a resistor and a diode connected in series with the inductor of each cross-over path; said first and second switching means are first and second transistors; said transistors each having first and second load electrodes and a base electrode; first and second resistors having first and second sides; a voltage input connection; said first sides of each resistor being connected to said voltage input connection; the second side of said first and second resistors being connected respectively to the first load electrodes of said first and second transistors; the second load electrodes of said first and second transistors being connected to a common point; said first inductor and one of said parallel combination of resistor and diode being connected in series between the second side of said second resistor and the base electrode of said first transistor; the second inductor and the other parallel combination of said resistor and diode being connected in series between the base electrode of said second transistor and the second side of the second resistor; said diodes being connected such that they oppose the current flow from the voltage input connection; said diodes producing a photocurrent when subjected to said high radiation which will be in the same direction as any current that may be flowing in the inductor of its cross-over path; and first and second output indicating means connected respectively to the second side of said first and second resistors so as to indicate the state of the flip-flop circuit.