SU1261065A1 - Source of rectangular voltage pulses - Google Patents

Abstract

The invention relates to a converter technique and can be used as a source for electroerosive and electroerosometic treatment of metals. The aim of the invention is to improve the accuracy of electroerosive and electroerosive-chemical processing. The device contains a voltage stabilization unit (BSN) connected between the filter choke I and the filter capacitor 8. BSN consists of thyristor 2, accumulative droplets 3, discharge diode 4, charge thyristor 5 and accumulative capacitor 6. Load 24 is connected through an injected diode limiter 23 to the cathodes of valves 21, 22 included in the diagonals of the alternating current of thyristor bridges. Protective chokes 9, 10 are included in the anodic v circuits of the cathode group of thyrioters 13, 14. The thyristor 5 is turned on during a pause, transferring the energy accumulated in choke I to capacitor 6. The thyristor 2 is turned on simultaneously with the bridge thyristors, feeding the capacitor 8 with chokes 1 and 3, with the result that rectangular pulses with a steep leading front and stiffness of the external characteristic increases. 2 pcs. / c 1 Od Od 01

Description

The invention relates to a converter technique, in particular to autonomous inverters, and can be used as a source for electroerosive and electroerosometic processing of metals.

The aim of the invention is to improve the accuracy in EDM and EDM processing by generating square voltage pulses with a steep leading edge and increasing the rigidity of the external characteristic of the source.

FIG. a diagram of a source of rectangular voltage pulses of adjustable duration and frequency for electroerosive and electroerosive metal processing; Fig. 2 shows the curves of the currents i 5 flowing through the thyristors i, i, j, the reverse diodes i, g of the first bridge and the currents i of the second bridge, as well as voltage pulses U, on the load.

The source contains a filter choke 1, to which a voltage stabilizing unit is connected, consisting of input thyristor 2, accumulative throttle 3, discharge diode 4 of charge thyristor 5, storage capacitor 6, discharge resistor 7, to this unit is connected capacitor 8 of filter , two thyristor bridges consisting of k, ajQ

One of the protective chokes 9 and 10, thyristors 11-14 with reverse diodes 15-18, capacitor 19 and oscillator throttles 20 / .C-circuit, oncoming valves (.c) 21 and 22 diode current limiter 23 is connected to the load 24.

The source of rectangular voltage pulses operates as follows.

When the thyristors 11 and 13 are turned on, the load 24 through the diode 21 and the diode limiter 23 instantly applies the voltage of the filter capacitor 8. The rise time of the leading edge of the pulse depends on the turn-on speed of the thyristor 11 and diode 21,

The oscillatory current flows through the thyristor II, capacitor 19, inductors 10 and 20, thyristor 13 and filter capacitor 8. At the same time, the load voltage 24 is formed at the load 24.

610652

coal form. When counter-diodes 15 and 17 operate, the voltage across the load does not change its shape and polarity.

5 When the counter diodes I 15 and 17 are turned off, the thyristors 12 and 14 are turned on, the whole process is repeated, but now the diode 22 is working and the voltage of the capacitor B of the filter of constant polarity and magnitude is still applied to the load. The same happens when the oncoming diodes 16 and 18 are turned on. As a result, when the inverter is operated on the load 24, square voltage pulses are generated, the duration and frequency of which can be regulated by the inverter control system within wide limits.

20 To obtain a rectangular pulse, the source of rectangular pulses contains at least two bridges operating alternately. When the thyristors 11 (13) of the first bridge are turned off, the thyristors 1I, 13 (12.14) of the other bridge are turned on. A continuous voltage pulse is generated in the load.

Elements 3-7 form a voltage stabilization unit on the filter capacitor 8. The thyristor 5 is turned on during pause, transferring energy, accumulated in choke 1, to capacitor 6. During the generation of pulses, the thyristor 2 is turned on simultaneously with thyristors 1.13. The current accumulated by choke 3 in the process of charge-discharge of capacitor 6, together with input current i

40 throttles 1 feed the capacitor 8, the voltage stiffness on which determines the stiffness of the external power supply characteristic.

Claims (1)

45 claims The source of rectangular voltage pulses 5 containing connected to the input terminals through the choke 50 filter thyristor bridges with reverse diodes, the diagonal of the alternating current of each of which includes a commutating, mutating LC circuit, shunted by two counter-sequential 55 connected valves, the connection point of the cathodes of which is connected to the load circuit connected to the negative input terminal, as well as the filter capacitor, that is, with the fact that, in order to improve the accuracy of electroerosive and electroerionic processing by forming voltage pulses of a rectangular shape with a steep leading front and increasing the rigidity of the external characteristic of the source, it supplied with block | Kom voltage stabilization on a capacitor filter Compiler I. Zherebina Mr. edactor L. Veselvska Tekhred L. Oliynyk. Korrektor.A.Zimokosov - V LJ J4: i -П-1 t I I II 11 I | I Order 5241/55 Circulation 631 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 pa, the diode limiter and the throttles included in the iodine circuits of the thyristors of the cathode groups of bridges, the voltage stabilization unit connected between the output choke and the filter capacitor connected in parallel to the bridges, and between the cathodes of the valves and the load circuit the diode limiter is turned on. FIG. 2