Patent ID: 8143550

Claim:
A device for depositing an electrically conductive electrode material in the form of a rod onto a surface of an electrically conductive work piece by electrical discharges, the device comprising: a capacitance bank for charging and discharging current pulses of predetermined durations and amplitudes; an electrically conductive electrode connected to the capacitance bank, the electrically conductive electrode acting as an anode; a vibro excitor configured to hold the anode on a work piece acting as a cathode, the surface of the cathode is desired to be coated; a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) having a drain that is connected to the capacitance bank; a protection circuit being connected between the drain and source of the MOSFET to protect the MOSFET against surge currents; a tuning circuit having a first terminal connected to the gate of the MOSFET to control the rate of discharge of the current pulses of predetermined durations and amplitudes; a rotary switch connected to a second terminal of the tuning circuit for selecting predetermined pulses generated by the tuning circuit; an alternating current transformer having a primary winding and three secondary windings, the primary winding connected to an AC source, each secondary winding being connected to a rectifier, one secondary winding being connected to the vibro excitor through a device for generating and controlling frequency and amplitude of the vibro excitor, another secondary winding being connected to the tuning circuit; an integrated circuit switch (I.C. switch) connected to a third terminal of the tuning circuit through a timing capacitor, the I.C. switch acting as a multiplexer and being connected to a set of variable resistors through a pulse tuning device for controlling on and off time of pulses that drive the MOSFET; means for applying a plurality of current pulses between the electrically conductive electrode and the work piece, wherein each pair of adjacent current pulses is separated in time by a pause during which no current flows between the electrically conductive electrode and the work piece; and means for controlling a duration of each current pulse and a duration of each pause between adjacent current pulses such that the duration of each pause is between two and five times a duration of the current pulse immediately preceding the pause, wherein a positive and a negative supply is fed to the variable resistors for charging and discharging pulses from the tuning circuit.