Laser initiated three electrode type triggered vacuum gap device

Claim 2

A triggered vacuum gap device comprising: an evacuated envelope; a first main arcing electrode disposed within said evacuated envelope; a second main arcing electrode disposed within said evacuated envelope facing said first main arcing electrode, and spaced therefrom to form a first arcing gap therebetween; a trigger electrode in close proximity to said second main electrode but electrically insulated therefrom by an open vacuum space, to form a second arcing gap therebetween; a voltage source connected between said trigger electrode and said second main electrode to form an electric field therebetween which has a value lower than the breakdown potential between said trigger electrode and said second main electrode; a gas-saturated metal piece located near said trigger electrode; laser means for heating said gas-saturated metal piece to release a gas in the second arcing region between said trigger electrode and said second main electrode to initiate a lowpower arc therebetween; and, magnetic means comprising said second main arcing electrode and said trigger electrode disposed with respect to said second main arcing electrode to form a current loop through said lowpower arc causing a magnetic force on said low-power arc for moving said low-power arc into the first arcing gap region between said first main contact and said second main contact to initiate a main power arc therebetween.

Claim 3

The apparatus as claimed in claim 1 wherein said triggering voltage source comprises a direct current supply and a current limiting resistor.

Claim 4

A triggered vacuum gap device as claimed in claim 1 wherein said trigger voltage source comprises an alternating current voltage supply, a voltage clipping device to limit peak value of said alternating voltage supply and a current limiting means.

Claim 5

A triggered vacuum gap device as claimed in claim 1 wherein a hollow conducting tube supports said first main arcing electrode, a transparent window supported in said hollow conducting tube, a laser beam projected from said laser means passing through said transparent window and said hollow conducting tube to impinge on said gas-saturated piece causing a gas to be released and initiating arcing between said trigger electrode and said second main arcing electrode.

Claim 6

A triggered vacuum gap as claimed in claim 4 comprising a second hollow conducting tube supporting said second main arcing electrode, a portion of said trigger electrode passing internal of said hollow conducting tube, insulating means for insulating said trigger electrode from said second hollow conducting tube, and said gas-saturated piece being attached to the end of said trigger electrode disposed within said hollow conducting tube.

Claim 7

A triggered vacuum gap as claimed in claim 5 wherein a portion of said insulating means in close proximity to said gas-saturated piece is of a smaller diameter than said hollow conducting tube to form a gap between a portion of said insulating means and the inner diameter of said second hollow conducting tube so that arc-generated metallic vapors and particles cannot condense on the solid dielectric between said trigger electrode and said second hollow conducting tube to cause a shorting path therebetween.

Claim 8

A triggered gap vacuum device as claimed in claim 1 wherein a bevel is formed on the inner diameter portion of said second main arcing electrode, said gas-saturated piece being mounted around said beveled portion of said second main arcing electrode so that when said laser means heats said gas-saturated piece, a low-power arc is formed between said beveled portion of said second main arcing electrode and said trigger electrode.

Claim 9

A triggered vacuum gap as claimed in claim 1, comprising: insulating means for supporting said trigger electrode, said gas-saturated piece comprises a metal disc that is saturated with hydrogen, said metal disc mounted at the end of said insulating means, said trigger electrode extending from said insulating means and passing through said gas-saturated metallic disc.

Claim 10

A triggered vacuum gap as claimed in claim 8 wherein said insulating means in the vicinity of said gas-saturated metallic disc is undercut to form a gap between said insulating means and said second main arcing electrode so that arc-generated metallic vapors and particles cannot coat the surface and form a shorting pass between said trigger electrode and said second main arcing electrode.

Claim 11

A triggered vacuum gap device comprising: an evacuated envelope; a first main arcing electrode disposed within said evacuated envelope; a first hollow support being formed from a conducting material for supporting said first main arcing electrode; a second main arcing electrode disposed within said evacuated envelope facing said first main arcing electrode and spaced therefrom to form first arcing gap therebetween; a second hollow support being formed from a conducting material for supporting said second main arcing electrode; a trigger electrode disposed within said second hollow support but electrically insulated therefrom to form a second arcing gap therebetween; a voltage source connected between said trigger electrode and said second main arcing electrode to form an electric field therebetween which has a value lower than the breakdown potential between said trigger electrode and said second main electrode; a gas-saturated metal piece located in close proximity to said trigger electrode; laser means for heating said gas-saturated metal piece to release a gas in the second arcing gap between said trigger electrode and said second hollow support to initiate a low power arc therebetween; and, said second hollow support and said trigger electrode being formed so that the magnetic field generated by the current flow when the low poWer arc is initiated forces the low power arc into the first arcing gap between said first main arcing electrode and said second main arcing electrode to initiate a main power arc therebetween.

Claim 12

A triggered vacuum gap device comprising: an evacuated envelope; a first main arcing electrode disposed within said evacuated envelope; a first hollow support being formed from a conducting material for supporting said first main arcing electrode; a second main arcing electrode disposed within said evacuated envelope facing said first main arcing electrode and spaced therefrom to form first arcing gap therebetween; a second hollow support being formed from a conducting material for supporting said second main arcing electrode; a trigger electrode disposed within said second hollow support but electrically insulated therefrom to form a second arcing gap therebetween; a voltage source connected between said trigger electrode and said second main arcing electrode to form an electric field therebetween which has a value lower than the breakdown potential between said trigger electrode and said second main electrode; a gas-saturated metal piece located in close proximity to said trigger electrode; laser means for heating said gas-saturated metal piece to release a gas in the second arcing gap between said trigger electrode and said second hollow support to initiate a low power arc therebetween; and, said second hollow support and said trigger electrode being formed so that the magnetic field generated by the current flow when the low poWer arc is initiated forces the low power arc into the first arcing gap between said first main arcing electrode and said second main arcing electrode to initiate a main power arc therebetween.

Claim 13

A trigger vacuum gap device as claimed in claim 10 wherein: said first hollow support comprises a hollow metallic tube extending through said evacuated envelope; said laser means is disposed external to said evacuated envelope and directs a laser beam into said evacuated envelope through said first hollow support; and including, a transparent member disposed within said hollow metallic tube through which the laser beam can pass and forming a vacuum tight seal with the inner surface of said hollow metallic tube.