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US 4,636,907 AGranted
Arcless circuit interrupter
AssigneeGeneral Electric Company
InventorEdward K. Howell
Life of this patent
Estimating the term…
Abstract
Arcless circuit interruption from metallic contacts is accomplished by the combination of a solid state current interrupter with a control circuit and an impedance circuit. The impedance circuit diverts the contact circuit current through the solid state current interrupter prior to initiating contact separation. The contacts then open without sufficient current transfer to establish an arc.
Claims22
A circuit interrupter comprising:
- a pair of separable contacts connected in series within an electric circuit;
- first and second circuit means connected within said electric circuit for preventing arc formation between said contacts upon separation;
- said second circuit means connected in series with said contacts for causing a circuit current to transfer to said first circuit means prior to separating said contacts;
- said first circuit means connected across the series combination of said contacts and said second circuit for conducting circuit current away from said contacts for a predetermined period of time before interrupting said circuit current;
- and
- operating means for separating said contacts while said first circuit means is conducting said circuit current.
3 more elements
A circuit interrupter comprising:
- a pair of separable contacts within a protected circuit under control of an operating mechanism for interrupting predetermined current through said circuit;
- a transformer having an input winding connected in series with said contacts having an output winding connected in parallel with a power transistor;
- a solid state switch connected in parallel with the series connection of said contacts and said transformer for conducting said current away from said contacts and for transferring said current to a voltage dependent element for causing said current to decrease to a predetermined low value;
- and
- means for applying drive signal to said power transistor to keep said transformer output winding at a first voltage while said contacts are in a closed condition and for removing drive signal to said power transistor immediately prior to separating said contacts said contacts to increase said transformer output winding to a second voltage greater than said first voltge.
2 more elements
A method for providing circuit interruption comprising the steps of:
- connecting a pair of separable contacts in series with first circuit means within an electric circuit;
- arranging second circuit means across said contacts and said first circuit means;
- operating said first circuit means for causing some of said circuit current to transfer to said second circuit means prior to opening said contacts;
- opening said contacts to interrupt remaining current flow through said contacts;
- and
- operating said second current circuit means for decreasing said transferred circuit current to a predetermined low value.
3 more elements
Dependencies are inferred from the claim text.