SU1591166A1 - Power supply system for electroplating bath - Google Patents

Description

The invention relates to electrical engineering and can be used as a power source with periodically varying direction and magnitude of current with adjustable duration. The purpose of the invention is to increase reliability. The device consists of a reverse transducer, made on two groups of thyristors connected to the stars of the secondary windings

The invention relates to electrical engineering, in particular to power sources, and can be used in electroplating to provide various electrolysis modes, as well as <in automatic control systems that require periodic changes in direction and magnitude of current with adjustable duration for this program.

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power transformer. The thyristor control electrodes are connected via the corresponding relay contacts to the output of the phase control unit, which is powered from a source including diodes connected to the secondary windings of the power transformer according to a rectifier circuit. Between the zero point of the windings and the cathodes of the thyristors are included the windings of the surge reactor, additionally equipped with a winding, bypass relay. Between the phases of the primary winding, the coils of the additional double-winding relay are connected. The contacts of the additional input of the indicated relays are connected in series with the circuit of the start and reset buttons and the magnetic starter. A reset button is included between the input pins to connect two adjacent phases of the mains supply. The introduction of a shunted winding into an equalization reactor and two additional relays provide protection against breakdown and failure of thyristors of the reversing converter. 3 il.

The purpose of the invention is to increase reliability.

FIG. 1 shows the electrical circuit of the system; in fig. 2 - electrical circuit of the sawtooth generator, which is part of the phase control thyristor unit of the reversing converter; ka fig.Z electrical circuit switching unit.

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The power supply system for the electroplating bath contains a power transformer 1 with star-operated 2-4 primary and secondary 5-13 $ included

windings, magnetic starter 14 with closing contacts 15 - 17 and a blocking contact 18 connected in parallel. the start button 19, the reset button 20, the current relay with in series connecting windings 21 and 22 and the disconnecting contact 23, the first group of thyristors 24–26, the second group of thyristors 27–29 reversing converter, switch unit 30 galvanic bath 31, diodes 32–34 of the power source of a three-channel thyristor phase control unit, a balancing reactor with the first 35, second 36 and third additional 37 windings.

In addition, four electromagnetic relays are included in the system: the first relay 38, the disconnecting contact 39 of which is connected in series with the winding .'5 of the second relay 40, having three opening 41 - 43 and three closing 44-46 contacts, the third relay 47, the winding of which is turned on parallel to the third

 the (additional) winding 37 of the equilibrium reactor, and its break contact 48 is connected in series with

breaking contact 23 current

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a relay with coils 21 and 22, a reset button 20, a start button 19, and a coil of a magnetic starter 14 between one of the phases and the common wire.

As the fourth relay, a current (adjustable) two-winding relay (coils) 21 and 22 is used. One 40 winding (coil) 22 is connected between the same-named terminals of the primary windings 3 and 4 of the specified transformer. Other same conclusions of the primary windings. 2-4 last 45 through the closure ^ contacts 15 - 17 of the magnetic starter 14 are connected to the phases of the network.

In this case, between the listed elements is the following electrical connection. The ends of the secondary windings 5 - 13 are electrically combined in groups of three, and their beginnings are connected respectively to the anodes of the thyristors 24 - 29 and the anodes of the diodes

"32 - 34, the cathodes of which are also electrically combined into groups of three, with the cathodes of thyristors 24 - 26 through series-connected windings

35 and 36 surge reactor connected to the ends of the secondary windings 8-10 of the power transformer 1, and the cathodes of the second group of thyristors 27 - 29 through the terminals of the ends of the secondary windings 5 - 7 connected to one of the conclusions of the plating bath 31, the other input of which is connected to a common point electrical connection of windings 35 and 36 of the equalization reactor. The common connection point of the secondary windings 11 - 13 of the power transformer 1 and the combined cathodes of the diodes 32 - 34 are connected to the power supply lines of the thyristor phase control system.

The phase control unit of each thyristor 24-29 consists of three identical channels 49 - 51, each of which includes a series 52 sawtooth voltage, Schmidt trigger 53, differentiating chain 54 and power amplifier 55, each input of channels 49 - 51 is connected to the beginnings, respectively, of the secondary windings 1113 of the power transformer 1, and the output is connected to the common terminals of the opening contacts 41 - 43 and then to the control electrode of the corresponding thyristor 24 - 26.

The sawtooth voltage generator 52 (FIG. 2) contains a limiting resistor 56, a divider of resistors 57 and 58 in the base circuit of transistor 59, the emitter of which is directly connected to the power bus, and the other bus is connected to the collector of this transistor through resistors 60 and 61. The specified collector through the capacitor 62 is also connected to the positive power supply bus.

Schmidt's trigger is made on transistors 63 and 64, in whose collector circuits resistors 65 and 66 are connected, resistor 67 in their emitters circuit, transistor 64 base is connected to transistor 63 via resistor 68, and via positive power bus 69 through resistor 69.

The collector of transistor 64 through a differentiating circuit (capacitor 70, resistor 71) is connected to the base of transistor 72, in the collector circuit of which

resistor 73 is turned on, and the emitter is nepos5 159116

rarely associated with a positive power bus.

At the same time, the collector of transistor 72 is connected via an opening contact 43 (FIG. 2) to the control electrode of the thyristor 26, the base of the transistor 63 and the collector of transistor 59 are connected directly, and its base is connected to the beginning of the secondary winding 13 of the power transformer via the limiting resistor 56 1, being a source of synchronizing voltage.

Switch unit 30 D1I (Fig., 3) contains 15 first 38 and second 40 electromagnetic relays, 'as well as a full-wave rectifier 74, the input of which is connected to the terminals of windings 9 and 10 of the power transformer 1, and the output - 20

to the filter consisting of resistor 75 and capacitor 76, limiting resistors 77 and 78, timers (resistors 79 and 80), microcircuit 81, functional purpose - timer KR-1006 type VI-1-, conclusions: a - common , b - start, in - output, d - reset, d - control of the divider, e - actuation, g - positive.

The capacitor 82 is connected to the pins d, b, and the chips 81 and the resistor 78 and to the common minus. The capacitor 83 is connected to the terminals of the capacitor 82 and the output of 'g of the chip 81 and the minus of the capacitor to the common minus of the circuit. The first electromagnetic relay 38 is connected to the output in the microcircuit 81 and the circuit negative, the second electromagnetic relay 40, duplicating the first, is switched on by means of the disconnecting contact 39 of the relay 38 for a voltage displacement of 220 V.

The terminals of the fixed parts 84-86 of the contacts of the second relay 40 are connected to the collectors of the transistors 72 of the power amplifiers of the thyristor phase control system. These elements form the element 87 adjustable time delay (Fig. 1).

The device also contains a KS filter (resistor 88-capacitor 89) connected between the anodes of diodes 32 to 34 and the common end output (zero point) of the secondary windings 11 to 13. This filter serves as a secondary power source for the thyristor phase control unit.

There is also a resistor 90 that controls the time of switching on the thyristors (depending on the requirements of the technology; 6

mode), resistors 91 ¹ and 92, designed for decoupling the control circuits called thyristors.

The system works as follows.

The duration of the supply to the galvanic bath 31 of the operating current in one or another polarity is established by means of the switching unit 30, which can operate in both static and cyclic modes. In the position indicated in FIG. 3, the coil of the relay 40 is energized for a certain (in accordance with the requirements of the technology) set time and during this period the second group of thyristors 27 - 29 is used, since the control signals from the thyristor phase control unit will (according to FIG. 3) thyristor group. Due to this, the working current is supplied to the galvanic bath of the SG of the working current in one direction.

In a cyclic mode (this is provided by the switching unit 30), the first relay 38 alternately turns into either switched on or in a de-energized state, therefore in this case the first relay 38 de-energizes in the next period of time, by disconnecting the second relay 40 from the power supply through opening contact 39. As a result, the contacts of the relay 40 will occupy the position indicated in FIG. 3. The control signals from the thyristor phase control unit will begin post-. on the first group of thyristors 2729, and the operating current through the galvanic bath 31 will change direction.

If the rated current consumed by this device exceeds the rated current, the current (fourth) two-winding relay 21,22 will operate and disconnect the coil of the magnetic starter 14 from the network with its opening contact 23.

During normal operation of all thyristors in cyclic mode, the pulsating currents in windings 35 and 36 of the surge reactor are the same, therefore the voltage on its third winding 37 is insignificant and the third relay 47 is de-energized, because the surge reactor is magnetized by a pulsating load current, and the variable component on its windings is small .

In the case of breakdown of one of the thyristors in the winding (35-37) equalizing

reactor associated with emergency corpse7

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Thyristors, an alternating short-circuit current will begin to flow, which in the conditions of bias of the surge reactor will cause a significant increase in the voltage on the third winding 37 of the latter and, as a result, the operation of the third relay 47.

As a result, its breakaway circuit 48 will also disconnect the magnetic starter 14 from the power source, i.e. The device as a whole is de-energized.

A resistor (potentiometer) 90 sets the tennological current and voltage.

Claims (1)

Claim Power system: 0 to ₂ Coy galvanic baths, comprising a three-phase magnetic switch, three-phase power transformer with three secondary windings in each phase, three-phase primary winding of which one 25 conclusions through the closing contacts. The specified magnetic starter is connected to the input terminals for connecting the corresponding phases of a three-phase network, a switching unit comprising an adjustable time delay element with two relays, a single-phase source, a switching unit power supply, start and reset buttons connected in series with the starter coil to form a chain connected between the input terminals for connecting two adjacent phases of the supply network, a two-winding reactor, a reversive thyristor converter consisting of two groups of other thyristors, a Phase unit th control thyristors in the form of three identical channels, each of which consists of. a series of sawtooth voltage generator, Schmidt trigger, a differentiating chain and a power amplifier connected in series, with the beginning of the first and second secondary windings of the power transformer connected to the anodes of the thyristors of the respective groups, the cathodes of the thyristors of each of the groups (combined into a common point, the free pins of the secondary windings in each phase are combined into a common zero point, while the zero $$ point of the first secondary winding is connected to the cathodes of the second thyristors: the group and forms the first one output for connecting galvanic Baths, the cathodes of the thyristors of the first group are connected to one of the conclusions of the first winding of the surge reactor, one of the conclusions of the second winding of which is connected to the zero point of the second secondary winding of the power transformer, the free ends of the two windings of the surge reactor are combined into a common point forming the second output terminal for connection galvanic bath, the beginning of the third secondary winding of a three-phase power transformer connected to the inputs of the sawtooth generator of the respective channels indicated o Phase thyristor control unit of the above groups and to the anodes of the diodes, the cathodes of which are combined into a common point connected through a QC filter with the zero point of the third, secondary winding connected through the first and second resistors, to the cathodes of the thyristors of the first and second groups, respectively, and the total the connection point of the resistor and capacitor of the KC filter and the zero point of the third secondary winding are connected to the power inputs of the specified phase control unit, the beginning of the two phases of the second secondary winding of the power transformer are connected the input of the single-phase power supply of the switching unit, the output of which is connected to the input of an element of adjustable time delay, the output of which is connected to the coil of the first relay, the disconnecting contact of which is connected to the corresponding phase of the supply network, the control electrode of each thyristor of the first group through one of the three disconnecting contacts of the second relay with the output of the power amplifier of the corresponding channel of the phase control unit, and the control electrode of each thyristor of the second group is connected to the output of the force The power of the corresponding channel of the phase control unit through one of the three closing contacts of the second relay, distinguished by the fact that, in order to improve reliability, the surge reactor is additionally equipped with a third winding, a shunt coil of the additionally introduced third electromagnetic relay, free terminals of the windings of the two extreme phases the primary winding of the power transformer is connected to the free output winding of the middle phase through the first and second coils respectively 9 1591166 ten additionally entered fourth relay, and the opening contacts of the third and fourth relays included sequentially into the coil circuit of the magnetic starter between the reset button and the corresponding input terminal. Fig1 I 1591166 Phi3.2 Fiz.Z