SU864409A1

SU864409A1 - Device for limiting on-no load voltage of welding transformer

Info

Publication number: SU864409A1
Application number: SU782683182A
Authority: SU
Inventors: Федор Егорович Хрущев
Original assignee: За витель
Priority date: 1978-11-09
Filing date: 1978-11-09
Publication date: 1981-09-15

Description

Изобретение относится к электротехнике и может быть использовано для питания электродуговой сварки при необходимости уменьшения напряжения холостого хода сварочного трансформатора. 5The invention relates to electrical engineering and can be used to power an electric arc welding, if necessary, to reduce the open circuit voltage of the welding transformer. 5

Известно устройство для снижения напряжения холостого хода сварочного трансформатора, содержащее блоки управления логики тиристоров и трансформаторов. В режиме холостого хода тиристоры пропускают в первичную обмотку сварочного трансформатора часть полуволн тока, ограничивая тем самым величину напряжения холостого хода. Увеличение тока первичной обмотки сварочного трансформатора при замыкании электродов вызывает срабатывание блока ,5 логики и полное открытие тиристоров [1].A device is known for reducing the open circuit voltage of a welding transformer, comprising control units for thyristor and transformer logic. In idle mode, the thyristors pass part of the half-waves of current into the primary winding of the welding transformer, thereby limiting the value of the open circuit voltage. An increase in the current of the primary winding of the welding transformer when the electrodes are closed causes the unit to trip, 5 logic and full opening of the thyristors [1].

Недостатком данного устройства является его значительная сложность.The disadvantage of this device is its significant complexity.

Наиболее близким по технической сущности к предлагаемому является устройство, содержа- jq щее сварочный трансформатор, первичная обмотка которого через контакты контактора подключена к питающей сети вместе с первичной обмоткой промежуточного трансформатора. Вто2 ричная обмотка последнего последовательно с дросселем, конденсатором и обмоткой реле подключена к вторичной обмотке сварочного трансформатора. Замыкающий контакт реле помещен в цепи обмотки контактора [2].The closest in technical essence to the proposed is a device containing jq welding transformer, the primary winding of which is connected through the contacts of the contactor to the mains together with the primary winding of the intermediate transformer. The secondary winding of the latter is connected in series with the inductor, capacitor and relay coil to the secondary winding of the welding transformer. The relay contact is placed in the contactor winding circuit [2].

Недостатком данного устройства является сложность, обусловленная наличием реле, конденсатора и дросселя.The disadvantage of this device is the complexity due to the presence of a relay, capacitor and inductor.

Цель изобретения — упрощение устройства.The purpose of the invention is to simplify the device.

Указанная цель достигается тем, что в устройстве для ограничения напряжения холостого хода сварочного трансформатора, содержащем контактор, два замыкающих контакта которого присоединены к шинам питающей сети вместе с первичной обмоткой промежуточного трансформатора, вывод первичной обмотки сварочного трансформатора соединен с одним из замыкающих контактов контактора, контактор выполнен с двумя обмотками, первая из которых подключена между вторым выводом первичной обмотки сварочного трансформатора и вторым замыкающим контактом контактора, а вторая обмотка контактора последовательно с вторичной обмоткой промежуточного трансформаторг через размыкающие контакты контактора подключена к его замыкающим контактам со стороны сварочного трансформатора.This goal is achieved by the fact that in the device for limiting the open circuit voltage of the welding transformer containing a contactor, two make contacts of which are connected to the busbars of the mains together with the primary winding of the intermediate transformer, the output of the primary winding of the welding transformer is connected to one of the make contacts of the contactor, the contactor is made with two windings, the first of which is connected between the second terminal of the primary winding of the welding transformer and the second make contact to contactors, and the second coil of the contactor in series with the secondary winding of the intermediate transformatorg through the break contacts of the contactor is connected to its normally open contacts from welding transformer.

На чертеже представлена схема устройства.The drawing shows a diagram of the device.

Устройство содержит промежуточный трансформатор 1 с первичной обмоткой, присоединенной к шинам питающей сети, к которой через замыкающие контакты 2 контактора и его обмотку 3 подключена первичная обмотка сварочного трансформатора 4. Вторичная обмотка промежуточного трансформатора 1 с последовательно соединенной обмоткой 5 контактора через его размыкающие контакты 6 присоединена к контактам 2.The device comprises an intermediate transformer 1 with a primary winding connected to the busbars of the supply network, to which a primary winding of the welding transformer 4 is connected through the make contacts 2 of the contactor and its winding 3. The secondary winding of the intermediate transformer 1 with a series-connected winding 5 of the contactor is connected through its opening contacts 6 to pins 2.

Устройство работает следующим образом.The device operates as follows.

В режиме хрлостого хода сварочный трансформатор 4 питается через промежуточный понижающий трансформатор 1, напряжение холостого хода невелико, а ток первичной обмотки сварочного трансформатора недостаточен для удержания контактора в сработанном состоянии. После замыкания сварочных электродов ток первичной обмотки сварочного трансформатора возрастает, что приводит к срабатыванию контактора, замыканию его контактов 2 и размыканию контактов 6. После окончания процесса сварки ток’первичной обмотки сварочного трансформатора 4 снижается до тока холостого хода,' контактор возвращается и сварочный трансформатор снова питается от промежуточного понижающего трансформатора 1.In idle mode, the welding transformer 4 is powered through an intermediate step-down transformer 1, the open circuit voltage is low, and the primary current of the welding transformer is insufficient to keep the contactor in operation. After the welding electrodes are closed, the current of the primary winding of the welding transformer increases, which leads to the contactor tripping, closing of its contacts 2 and opening of contacts 6. After the welding process is completed, the current of the primary winding of the welding transformer 4 decreases to no-load current, the contactor returns and the welding transformer again powered by an intermediate step-down transformer 1.

Положительный эффект применения изобретения заключается в ограничении напряжения холостого хода сварочного трансформатора-The positive effect of the application of the invention is to limit the open circuit voltage of the welding transformer -

Claims

The invention relates to electrical engineering and can be used to power electric arc welding, if necessary, to reduce the no-load voltage of a welding transformer. A device for reducing the no-load voltage of a welding transformer is known, which contains control units for thyristor logic and transformers. In the idling mode, the thyristors pass into the primary winding of the welding transformer a part of the half-current, thereby limiting the value of the no-load voltage. The increase in the current of the primary winding of the welding transformer when the electrodes are closed causes the operation of the logic unit and the full opening of the thyristors 1. The disadvantage of this device is its considerable complexity. The closest in technical essence to the present invention is a device containing a welding transformer, the primary winding of which is connected to the supply network through the contacts of the contactor along with the primary winding of the intermediate transformer. The secondary winding of the latter is connected in series with the choke, the capacitor and the relay winding are connected to the secondary winding of the welding transformer. The closing contact of the relay is placed in the winding circuit of the contactor 2. The disadvantage of this device is the complexity due to the presence of the relay, capacitor and throttle. The purpose of the invention is to simplify the device. This goal is achieved by the fact that in the device for limiting the no-load voltage of a welding transformer containing a contactor, two closing contacts of which are connected to the supply mains along with the primary winding of the intermediate transformer, the output winding of the welding transformer is connected to one of the closing contacts of the contactor, the contactor You are “complete with two windings, the first of which is connected between the second output of the primary winding of the welding transformer and the second closing contact contactor, the contactor and the second winding in series with the secondary winding of the transformer promezhztochnogo through the break contacts of the contactor is connected to its normally open contacts from welding transformer. The drawing shows a diagram of the device. The device contains an intermediate transformer 1 with a primary winding connected to the mains supply, to which the primary winding of the welding transformer 4 is connected via the make 2 contacts of the contactor and its winding 3. The secondary winding is pro. interstitial transformer 1 with a series-connected grounding of the contactor 5 through its opening contacts 6 is connected to contacts 2. The device operates as follows. In the idle mode, the welding transformer 4 is fed through the intermediate step-down transformer 1, the no-load voltage is low, and the primary current of the welding transformer is insufficient to keep the contactor in the actuated state. After the welding electrodes are closed, the current of the primary winding of the welding transformer increases, which leads to actuation of the contactor, closing its contacts 2 and opening the contacts 6. After the welding process is finished, the primary current of the welding transformer 4 decreases to the idling current is returned to the contactor again and the welding transformer is powered by an intermediate step-down transformer 1. The positive effect of the use of the invention is to ograshgchenii idling voltage of the welding transformer. Apparatus of the Invention A device for limiting the no-load voltage of a welding transformer comprising a contactor, two closing contacts of which are connected to the mains of the supply network together with the primary winding of the intermediate transformer, the output of the primary winding of the welding transformer is connected to one of the closing contacts of the contactor, characterized in that In order to simplify, the contactor is made with daum windings, the first of which is connected between the second output of the primary winding of the welding transformer and the second m the closing contact of the contactor, and the second winding of the contactor in series with the secondary winding of the intermediate transformer through the disconnecting contacts of the contactor is connected to its closing contacts from the side of the welding transformer. Sources of information taken into account during the examination 1. Device for reducing the no-load voltage of welding transformers USNT-0542. Technical description.

2. Author's certificate of the USSR N 102843, cl. H 02 H 7/04, 1964.

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