Abstract: A wire electrical discharge machine includes: a voltage application unit for repeatedly applying a voltage to an electrode gap between the workpiece and the wire electrode at a predetermined cycle; a switching element connected in parallel with the electrode gap and configured to short-circuit the electrode gap; and a control section for controlling the switching element so as to short-circuit the electrode gap in a pause period during which the voltage is not applied. The control section adjusts a short-circuiting period in which the electrode gap is short-circuited according to the machining shape specified by a machining program.

Abstract: Systems for operating a rectifier are provided. Aspects include a rectifier including a set of bridge structures configured to receive an input current of a power supply, wherein each bridge structure in the set of bridge structures includes a set of diodes and a set of active switches, wherein each active switch in the set of active switches is configured to provide a parallel path around each diode in the set of diodes when in a PWM state, a controller configure to determine a threshold current for the rectifier and operate one or more active switches in the rectifier in a PWM state based on the input current being less than the threshold current.

Abstract: The disclosed technology generally relates to electrical overstress protection devices, and more particularly to electrical overstress monitoring devices for detecting electrical overstress events in semiconductor devices. In one aspect, a device configured to monitor electrical overstress (EOS) events includes a pair of spaced conductive structures configured to electrically arc in response to an EOS event, wherein the spaced conductive structures are formed of a material and have a shape such that arcing causes a detectable change in shape of the spaced conductive structures, and wherein the device is configured such that the change in shape of the spaced conductive structures is detectable to serve as an EOS monitor.

Abstract: An electric discharge machine performs a hole machining on a workpiece by applying a voltage between an electrode and the workpiece to generate an electric discharge therebetween and moving the electrode to a position of a command depth. The electric discharge machine comprises: a storage unit; a current-coordinate detection unit; an electric-discharge-voltage detection unit a penetration detection unit; and a calculation unit. The storage unit stores therein a penetration determination voltage, a penetration determining duration, and a first projecting amount. The current-coordinate detection unit detects a current position of the electrode. The electric-discharge-voltage detection unit detects a minimum voltage of the electric discharge for each predetermined period. The penetration detection unit determines the electrode has penetrated through the workpiece.

Abstract: An electric discharge machine is provided with a rotary table disposed in a working tank and fitted with an object to be machined. The rotary table is provided with a working fluid penetration detection unit configured to detect penetration of a working fluid into the rotary table body.

Abstract: An electrical device for performing a particular function includes a system circuit for performing the function, and a dedicated power supply for providing power to the circuit. Both the system circuit and the power supply are hermetically sealed within a housing. The device within the housing is intended to be sterilized using high temperature, reaching a sterilization temperature. According to the invention, the device includes a thermal switch which is electrically connected between the system circuit and the power supply. The thermal switch is switchable between an open position wherein the system circuit is electrically isolated from the power supply and receives no power therefrom and a closed position wherein the system circuit is electrically connected to the power supply and receives power therefrom. The thermal switch switches from its closed position to its open position in response to the temperature within the housing rising to a predetermined switch-open temperature value.

Abstract: A wire inserting method comprises a pipe inserting step of inserting one pipe (5) into all through-holes (11) under the state where the plurality of through-holes (11) are arranged on the same axis, a wire inserting step carried out after, or in parallel with, the pipe inserting step, for inserting the electrode wire (2) through the pipe (5), and a pipe removing step of pulling out only the pipe (5) from the through-holes (11) after the wire insertion step.

Abstract: For specifying a cause of generation of a water level abnormality alarm in a wire-cut electric discharge machine, stopping supply of a machining liquid to a machining tank when the alarm is generated, draining the liquid; measuring an amount of change in the water level per unit time that is detected by the water level detecting unit; and displaying a question to an operator about the measured amount of change in water level and the state of a water level adjusting mechanism. The operator manually inputs an answer to the displayed question, and specifies, from the answer input by means of the inputting unit, a part which causes the generation of the alarm.

Abstract: A lower arm is passed through a slot in a machining tank. The slot of the machining tank is provided with a seal section for sealing with a plate-shaped seal member. The movable table is moved by a servomotor. The machining tank and a workpiece are fixed on the movable table. At the seal section, a seal member on the machining tank side slides with respect to the plate-shaped seal member, thereby generating a sliding resistance. This sliding resistance increases as a sludge produced by electric discharge adheres to the seal section, thereby distorting the lower arm and influencing the machining accuracy. Accordingly, a load that acts on the servomotor is detected, and a sliding resistance load at the seal section is obtained. When a reference load is exceeded by the detected resistance load, arrival of the seal section at the timing for maintenance is displayed and notified.

Abstract: A method and apparatus for electrical discharge machining of a workpiece wherein an erosion pulse is applied on the tool electrode. During the time of the erosion pulse the voltage (Ue) set on the electrode is acquired, and the erosion pulse is interrupted, after an asymptotic behavior of the acquired voltage (Ue) or a value derived therefrom has been acquired. Before the interruption of the erosion pulse an increase of current may occur.

Abstract: An electrical discharge machining apparatus includes a simulator. The simulator calculates machining information relating to machining shape at each of several simulated machining depths, when the electrode is moved into a workpiece, until an input machining depth is obtained, based on the shape of the electrode input, the shape of the workpiece, and the machining depth of the workpiece, and determines a shape obtained by subtracting the machining shape from the shape of the workpiece, as a new shape of the workpiece, at each simulated machining depth.

Abstract: In a power supply apparatus for discharge surface treatment which uses a green compact electrode as a discharge electrode, allows a pulse-type discharge to take place between said discharge electrode and a workpiece, and forms a film, which is made of an electrode material or a material obtained when the electrode material reacts to a discharge energy, on a surface of the workpiece following three measures are taken. (1) When a discharge voltage detected by the voltage detection means is less than or equal to discharge detection voltage set value which is slightly lower than a power supply voltage, the electric current cut-off means forcibly cuts off an output of the oscillator so that long-time pulse is prevented. (2) A capacitor is connected in parallel with an oscillation circuit of the oscillator, and the long-time pulse is prevented by capacitor discharge. (3) Time that the discharge takes place once is controlled by a timer so that the long-time pulse is prevented.

Abstract: An electrode discharge machining apparatus includes a first holder for holding a workpiece to be subjected to electro discharge machining, an electrode provided opposing the workpiece held by the first holder, a capacitor for supplying electric charge to the electrode and the workpiece so as to generate pulse electro discharge between the workpiece and the electrode, a power source for applying a voltage to the capacitor, a switching element provided between the capacitor, and at least one of the electrode, the workpiece and the power source, a switch controller for controlling on and off of the switching element, a current detecting element for detecting a current flowing between the workpiece and the electrode, and a control unit for, based on the current detected by the current detecting element, judging whether or not a short circuit occurs between the workpiece and the electrode.

Abstract: In an electric discharge machining apparatus for performing machining while relatively rocking an electrode (18) and a workpiece (W) in a plane vertical to a machining feed direction, there is provided an electric discharge state detection device (20) for detecting an electric discharge state by detecting a short-circuit frequency between the electrode and the workpiece, a defective electric discharge frequency and a position of the electrode, and a rocking function setting device (23) for setting parameters about a rocking function according to the electric discharge state detected by the electric discharge state detection device (20). A parameter setting about a rocking function according to the detected electric discharge state is automatically made without compelling an operator to make the parameter setting about the rocking function, and improvement in machining efficiency and stabilization of the machining can be achieved.

Abstract: An electro discharge machining apparatus comprises a first holder for holding a workpiece to be subjected to electro discharge machining, an electrode provided opposing the workpiece held by the first holder, a capacitor for supplying electric charge to the electrode and the workpiece so as to generate pulse electro discharge between the workpiece and the electrode, a power source for applying a voltage to the capacitor, a switching element provided between the capacitor, and at least one of the electrode, the workpiece and the power source, a switch controller for controlling on and off of the switching element, a current detecting element for detecting a current flowing between the workpiece and the electrode, and a control unit for, based on the current detected by the current detecting element, judging whether or not a short circuit occurs between the workpiece and the electrode.

Abstract: A power supply for an electric discharge machine which provides electrical power intermittently for discharge machining in a machining gap formed between an electrode and a work piece. The power supply comprises a direct current power source, a switching element connected between the direct current power source and the processing gap, a gate pulse generating circuit which generates a gate pulse signal for energizing the switching element and a protection network connected between the switching element and the gate pulse generating circuit.

Abstract: An apparatus for electrochemically machining of a workpiece by means of an electrode has an actuator for setting a gap between the electrode and the workpiece. The apparatus further has a channel for flushing the gap with an electrolyte and a container for containing the electrolyte. Power cords and are provided for feeding an electric current I supplied by a power supply through the electrolyte in the gap. Near the gap an antenna is provided to pick up electromagnetic waves radiated from the gap. The antenna is connected to a band-pass filter which passes signals in a frequency band of 40 to 100 MHz to a level detector. The level detector compares the amplitude of the filtered signal with a threshold value and supplies a stop signal to the control unit when the amplitude exceeds the threshold value. The control unit is programmed to open a switch in the power supply in response to the stop signal.

Abstract: An apparatus and method is provided for generating an electric discharge in an alternating direction on a workpiece for line cutting of the workpiece. In particular, the apparatus and method allows the benefits of preventing the workpiece from being cut apart due to excessive power and also preventing electrolysis that can degrade the surface quality of the workpiece. The apparatus includes a negative ignition voltage source, a positive ignition voltages source, a discharging voltage source, and a pulse generator, which are constructed on an all-transistor architecture.