A method for electrical discharge machining a work piece using rectangular processing pulses includes forming the rectangular processing pulses by discharging one or multiple discrete delay lines that comprise multiple storage elements. The storage elements are arranged as part of a feed line to a spark gap on a section of the feed line near the spark gap. The discrete delay lines are connected to a guide head by an electrode-side contact unit and are connected to the work piece by a work piece-side contact unit.

A wire electrical discharge machine includes: a supporting member for relatively moving a wire electrode relative to a measurement target; servomotors for moving the supporting member; a setting changer for changing the setting of a directive speed; and a motor controller that controls the servomotors in performing move-and-contact detection for detecting contact between the wire electrode and the measurement target by moving the two relative to each other, so that the wire electrode is moved relative to the measurement target based on the directive speed changed and specified by the setting changer.

Circuitry for driving a variable capacitive load comprising: a variable capacitive load; a digital control circuit configured to generate a digital drive signal; and a drive circuit configured to convert the digital drive signal into an analogue drive signal, the analogue drive signal forming a drive waveform for charging the variable capacitive load, the drive circuit comprising a slewing circuit configured to drive a time dependent voltage component of the drive waveform; wherein the digital control circuit is configured to modify the digital drive signal for each charging cycle so as to match the time dependent voltage component of the drive waveform to the variable capacitive load.

A method of detecting the state of a gap between an electrode and a workpiece in electrical discharge machining (EDM) equipment, the method including the steps of: prior to generating an electrical discharge to remove material from the workpiece, applying a low energy checking pulse across the gap during a checking phase period (T.sub.c); and inferring a short circuit gap state when the gap current exceeds a current threshold (I.sub.T).

A machining power supply device for an electric discharge machine performs control to turn on a first semiconductor switching element, which is arranged in series between a DC power supply and a capacitor connected in parallel with a machining gap between an electrode and a workpiece, to charge the capacitor, and turn on a second semiconductor switching element, which is arranged in parallel with the capacitor and connected to a rectifier element, within a period in which the first semiconductor switching element is off.

A method for controlling a wire electrical discharge machining process, wherein the method comprises the following steps: dividing a workpiece height H.sub.WP into a number N.sub.S of vertical sections S of the workpiece, setting a defined observation period T.sub.M, N.sub.DTM, with each discharge Di, determining a discharge position of each discharge, counting the number of discharges determining any numbers of discharges and adjusting at least one process parameter.

A wire electrical discharge machining apparatus capable of improving the shape precision of a continuous corner part includes a corner speed coefficient calculation device calculating a machining speed ratio between a middle corner section and a straight part from a machining volume ratio between the straight part and the middle corner section in which machining volume becomes a constant value. A corner speed coefficient interpolation device interpolates a speed coefficient calculated by the corner speed coefficient calculation device in a pre-corner section and a post-corner section. A speed reference calculation device calculates a machining speed reference based on a representative speed and the corner speed coefficient, and a drive control device controls a drive device. A continuous corner detection device determines whether continuous corner sections overlap each other when the length of the straight part connecting two corner parts is shorter than the length of the pre-corner section.

A portable movable discharge processing system by short electric arc, including a power supply cooling water tank, a short electric arc cutting power supply, a ring current device a feeding mechanism, a hanging bracket and a pneumatic ring current tool mounted on the hanging bracket, which are successively and cooperatively mounted on a horizontal plane; an air compressor and a sewage pump, which are successively connected to the feeding mechanism; a self-priming pump and a movable short-electric arc cutting device control cabinet, which are successively connected to the air compressor; an anode device which is connected to the movable short-electric arc cutting device control cabinet through an anode cable; a cathode device which is connected to the movable short-electric arc cutting device control cabinet through a cathode cable; and a water pump which is connected to the anode device through a pipeline.

A machining method for three-dimensional open flow channel using high-speed arc discharge layered sweep, which arranges an axial line of an installation shaft of a tool electrode with six degrees of freedom to be perpendicular to an axial line of a to-be machined work piece in an arc discharge process, with the tool electrode sweeping in a closed path in a plane or a curved surface perpendicular to the installation shaft, wherein the path of the sweeping satisfies: a space of an enveloped space being formed by the tool electrode moving in the path and being coincident with a removed portion of the work piece does not exceed a preset machined cavity of the flow channel. The present invention is based on high-speed arc discharge of hydrodynamic arc breaking and realized layered milling and surface machining for three-dimensional open flow channels.

An electric discharge machine includes a DC power supply, a main switching element, a polarity switching circuit, a pulse generator, a detector, and a discharge controller. The DC power supply supplies a current to a machining gap. The pulse generator switches the main switching element and one of a positive switching element and a reverse switching element of the polarity switching circuit at a predetermined switching frequency. The detector detects an interpolar voltage in the machining gap. The discharge controller includes a storage that stores a coefficient indicating a removal quantity per discharge count for each operation pattern, and a calculator that calculates the discharge count from the interpolar voltage and estimates the removal quantity from the discharge count and the coefficient according to the operation patterns.