DD150169A1 - CIRCUIT ARRANGEMENT FOR GENERATING REVERSE VOLTAGE PULSE FOR ELECTROSIVE METAL WORKING - Google Patents

Abstract

The invention relates to a circuit arrangement for achieving Zuendspannungsimpulsen without dasz a high supply voltage is necessary by a series circuit switching transistor spark gap when blocking the transistor, a capacitor is charged, the entlaedt when restarting the transistor via a Impulsuebertrager, wherein the the secondary side of the transmitter resulting voltage pulse is connected in series with the primary voltage source, so dasz is applied to the spark gap, the sum voltage.

Description

Title of the invention

Circuit arrangement for generating ignition voltage pulses for electrical discharge machining

Application of the invention

The invention relates to a circuit arrangement for generating ignition pulses within a pulse generator for electrical discharge machining, in which the switching element is in series with the spark gap.

Characteristic of the known technical solutions

In order to obtain a large gap between the electrode and the workpiece necessary for the removal of the abrasive particles, it is common practice for a low-power starting pulse to be superimposed on a low-power ignition pulse at the beginning of the working pulse In addition, a plurality of circuit variants with different supply voltages coupled independently of one another and coupled by diodes are common, the circuit variant for generating the ignition pulse voltage being both a conventional series circuit with high supply voltage corresponding to the ignition pulse voltage and circuit variants operating at the same supply voltage from the startup

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or off edge of the power pulse can derive the ignition voltage can be ·

Object of the invention

The aim of the invention is to avoid the disadvantages of the known embodiments and to find a technical solution to obtain the advantages of gap widening by obtaining a Zündspannungsimpulses without high Yersorgungsspannung ·

Presentation of the essence of the invention.

The object is to achieve the ignition voltage pulses by means of transistors with low collector voltage and continue to meet the desire, the ignition voltage. The object is achieved with the invention in that a capacitor connected in parallel with the spark gap via a resistor and a decoupling diode is connected in parallel with a capacitor which is charged when the transistor is turned off is recharged via a pulse transformer when switched on again and that the voltage pulse arising on the secondary side of the pulse transformer is connected in series with the primary voltage source and is supplied to the spark gap.

embodiment

The circuit arrangement according to the invention will be explained in more detail below using an exemplary embodiment. The accompanying drawings show:

Figo 1 block diagram

Pig «, 2 voltage and current profiles

~ 3 ~ 220656

In Pig. 1 is shown a basic circuit of a pulse generator in series connection of a switching transistor to the spark gap with the Zündpulsvariante invention. In this case, the proportion of the pulse generator from the spark gap 1, the primary voltage source 2 with voltage Uo, a current limiting resistor 5 and a switching transistor 3 with pulse generation 4 and a Überspannungsableitdiode 6 «The Zündpulsschaltung consists of a decoupling diode 10 and a storage capacitor 11, the transformer 8, the Once resistor 9 for setting the ignition current level and «width and a decoupling diode 7 ·

The operation of the Zündpulsschaltung is the following: When blocking the S ehalt transistor 3 is charged via an additional decoupling diode 10, a storage capacitor 11 to the voltage Uo of the primary voltage source 2 · When switching on the switching transistor 3, the storage capacitor 11 via a pulse transformer 8 and a resistor 9 is discharged , the negative voltage pulse produced on the secondary side of the transformer 8 at the coupling diode 7 is connected in series with the primary voltage source 2, so that the sum voltage is applied thereto at the spark gap 1.

FIG. 2 illustrates the voltage and current profiles according to the circuit arrangement.

Claims (3)

1 «circuit arrangement for generating Zündspannungsimpulsen for electrical discharge machining, characterized in that to a resistor (9) and decoupling diode (10) connected in series with the spark gap switching transistor (3), a capacitor (11) is connected in parallel, the blocking of the Switching transistor (3) is charged and discharged when restarting via a pulse transformer (8) and that. the secondary side of the pulse transformer (8) resulting voltage pulse in series with the primary voltage source (2) is connected and the spark gap is supplied. 2. Circuit arrangement according to item 1, characterized in that the pulse height and width are predetermined and adjustable by the passive components (9, 11, 5) » - »- 2 20656 invention claims 3 · Circuit arrangement according to items 1 and 2, characterized. in that the maximum voltage applied to the switching transistor (3) is less than the starting voltage. See drawings!