Thyratron safety circuit

Claim 2

In combination with a firing circuit having a gas-tube thyratron, an electronic safing circuit For maintaining the firing circuit safe in the presence of a nuclear explosion without permanently dudding the firing circuit for use after the explosion is over; said firing circuit comprising in addition to said thyratron: means applying a cut-off bias to said thyratron, means for applying an input signal to overcome said bias and fire said thyratron, a firing capacitor, means for charging said capacitor to a voltage sufficient to fire said thyratron, and a load, said thyratron, capacitor and load being connected so that the firing of said thyratron by said input signal causes said capacitor to discharge through said thyratron to activate said load; said safing circuit comprising; a second gas-tube thyratron located so as to be at least as sensitive to firing by a nuclear explosion as is the gas-tube thyratron of said firing circuit, means biasing said second thyratron to cut-off, and means connecting said second thyratron effectively in parallel with said firing capacitor; the occurrence of a nuclear explosion thereby causing said second thyratron to fire no later than simultaneously with the thyratron of said firing circuit, whereupon said second thyratron effectively shorts out said capacitor so that substantially no energy flows to said load, said firing capacitor recharging to ready the firing circuit for later firing after the nuclear explosion is over.

Claim 3

In combination with a firing circuit having a gas-tube thyratron, an electronic safing circuit for maintaining the firing circuit safe in the presence of a nuclear explosion without permanently dudding the firing circuit for use after the explosion is over, said thyratron having at least a plate, a grid and a cathode, said firing circuit comprising in addition to said thyratron: means applying a cut-off bias between the grid and cathode of said thyratron, means applying an input signal to said grid to overcome said bias and fire said thyratron, a firing capacitor, means for charging said capacitor to a voltage sufficient to fire said thyratron, and a load, said thyratron, capacitor and load being connected so that the firing of said thyratron when said input signal is applied to said grid causes said capacitor to discharge through said thyratron between the plate and cathode thereof to activate said load; said safing circuit comprising: a second gas-tube thyratron having a plate, a grid and a cathode located so as to be at least as sensitive to firing by a nuclear explosion as is the gas-tube thyratron of said firing circuit, means applying a cut-off bias between the grid and cathode of said second thyratron, a protective resistor in series with the plate and cathode of said second thyratron, said resistor being of a very much lower value than the resistance of said load, and means connecting the series combination of said resistor and the plate and cathode of said second thyratron in parallel with said firing capacitor; the occurrence of a nuclear explosion thereby causing said second thyratron to fire no later than simultaneously with the thyratron of said firing circuit, whereupon most of the energy in said capacitor passes through said second thyratron and said resistor so that substantially no energy flows to said load, said firing capacitor recharging to ready the firing circuit for later firing after the nuclear explosion is over.

Claim 4

In combination with a firing circuit having a gas-tube thyratron, an electronic safing circuit for maintaining the firing circuit safe in the presence of a nuclear explosion without permanently dudding the firing circuit for use after the explosion is over, said thyratron having at least a plate, a grid and a cathode, said firing circuit comprising in addition to said thyratron: means applying a cut-off bias between the grid and cathode of said thyratron, means applying an input signal to said grid to overcome said bias and fire said thyratron, a firing capacitor, means for charging said capacitor to a voltage sufficient to fire said thyratron, and a load, said thyratron, capacitor and load being connected so that the firing of said thyratron when said input signal is applied to said grid causes said capacitor to discharge through said thyratron between the plate and cathode thereof to activate said load; said safing circuit comprising: a second gas-tube thyratron having a plate, a grid and a cathode located so as to be at least as sensitive to firing by a nuclear explosion as is the gas-tube thyratron of said firing circuit, means applying a cut-off bias between the grid and cathode of said second thyratron, a protective resistor in series with the plate and cathode of said second thyratron, said resistor being of a very much lower value than the resistance of said load, and means connecting the series combination of said resistor and the plate and cathode of said second thyratron in parallel with said firing capacitor; the occurrence of a nuclear explosion thereby causing said second thyratron to fire no later than simultaneously with the thyratron of said firing circuit, whereupon most of the energy in said capacitor passes through said second thyratron and said resistor so that substantially no energy flows to said load, said firing capacitor recharging to ready the firing circuit for later firing after the nuclear explosion is over.

Claim 5

A firing circuit protected against premature detonation due to nuclear explosions comprising: a firing tube and a protective tube in parallel connection, a firing capacitor connected in parallel with said protective and firing tubes, voltage means connected to said firing capacitor for charging said capacitor to some predetermined value, biasing means connected to said protective tube for rendering the protective tube normally nonconducting, a detonator connected to said firing tube, means for causing said protective tube to ionize at the same time or before the firing tube ionizes in the presence of a nuclear explosion, and means for causing said firing capacitor to dischaRge through said protective tube rather than said firing tube when both of said tubes are ionized.

Claim 6

A firing circuit protected against premature detonation due to nuclear explosions comprising: a firing tube and a protective tube in parallel connection, a firing capacitor connected in parallel with said protective and firing tubes, voltage means connected to said firing capacitor for charging said capacitor to some predetermined value, biasing means connected to said protective tube for rendering the protective tube normally nonconducting, a detonator connected to said firing tube, means for causing said protective tube to ionize at the same time or before the firing tube ionizes in the presence of a nuclear explosion, and means for causing said firing capacitor to dischaRge through said protective tube rather than said firing tube when both of said tubes are ionized.