Alternating-current electric grinding method for conductive contact surfaces

The invention discloses an alternating-current electric grinding method for conductive contact surfaces, which includes the following steps that: (1) alternating-current pulse current is applied on the closing contact of a working surface to be cleaned, and generates voltage drop on a resistor, and charging voltage is generated at both ends of equivalent capacitors formed by dirt and local air clearance; (2) when the charging voltage is higher than the withstood breakdown voltage of the equivalent capacitors of the stained surface and the withstood voltage of the equivalent diodes of copper oxide, the stained surface and the oxidized layer are broken down by the current, so that electric sparks are discharged, and thereby the attached dirt and copper oxide can be cleaned up by the electric sparks. The invention has the following remarkable characteristics that: conductive contact surfaces can be ground on line, so that the dismounting and disassembly of equipment parts are dispensed with, consequently, the efficiency and reliability of repair are greatly increased, and in particular, the invention overcomes the defect that the direct-current pulse current grinding method cannot effectively treat copper-oxidized films.