Блок питания с регулировкой тока и напряжения своими руками

Всем известно, что мощный регулируемый блок питания с регулировкой напряжения и тока самое популярное и востребованное электронное устройство, с изготовления которого начинают свой творческий путь начинающие радиолюбители. Схем очень много, какую выбрать и с чего начинать многие просто теряются. Одним нужен простой лабораторный блок питания с регулировкой напряжения и тока, другим мощное зарядное устройство для зарядки автомобильного аккумулятора, а я предлагаю вам собрать своими руками простой универсальный блок питания с регулировкой напряжения и тока, который можно использовать для выполнения любых задач, питания электронных самоделок и зарядки автомобильного аккумулятора. Все, что от вас потребуется это усидчивость, минимальные знания электроники и умение пользоваться паяльником. А если возникнут вопросы, задавайте их в комментариях, я вам обязательно помогу.

Хватит слов приступим к делу!

На этом рисунке изображена схема блока питания с регулировкой напряжения и тока от 2.4В до 28В и силой тока до 30А.

Схема блока питания с регулировкой тока и напряжения от 2.4В до 28В 30А

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Важным элементом данной схемы является регулируемый стабилизатор напряжения микросхема TL431 или, как ее еще называют управляемый стабилитрон позволяющий плавно регулировать напряжение от 2.4 вольта до 28 вольт. Благодаря четырем силовым транзисторам, установленным на больших радиаторах, блок питания может выдержать ток до 30А. Также имеется регулировка тока и защита от переполюсовки, поэтому блок питания можно и даже нужно использовать, как зарядное устройство для автомобильного аккумулятора.

Делитель напряжения, построенный на мощном 5 Вт резисторе R1 и переменном резисторе Р1 ограничивает  ток на катоде и на управляющем электроде стабилитрона TL431. Вращением ручки переменного резистора Р1 задается выходное напряжение стабилитрона, стабилизатор напряжения TL431, автоматически стабилизирует напряжение заданное переменным резистором Р1. С микросхемы TL431 ток поступает на базу транзистора Т1. Транзистор  выполняет роль ключа и управляет двумя мощными биполярными транзисторами Т2 и Т3 соединенных параллельно для увеличения выходной мощности. В выходной каскад транзисторов установлены уравнительные резисторы R2 и R3. Далее ток поступает на плюсовую клейму блока питания.

Как работает регулировка тока?

В данной схеме реализована функция ограничения тока на двух мощных полевых транзисторах Т4 и Т5 соединенных параллельно. Давайте рассмотрим, как это работает. С диодного моста ток поступает на стабилизатор  напряжения L7812CV, напряжение снижается до 12В, это безопасное значение для затворов транзисторов. Далее ток поступает на делитель напряжения собранный на переменном резисторе Р2 и постоянном резисторе R4. С движка переменного резистора Р2 ток проходит через тока ограничительные резисторы R5 и R6 открывая затворы полевых транзисторов Т4 и Т5. Транзисторы проводят через себя определенное количество тока в зависимости от сопротивления переменного резистора Р2. В данной схеме ток регулируется при любом выходном напряжении.

Также предусмотрена защита от переполюсовки, состоящая из двух светодиодов. Зеленый светодиод сигнализирует о правильном подключении автомобильного аккумулятора к выходу блоку питания, а красный светодиод, о ошибке подключения. Резисторы R7 и R8 ограничивают ток для светодиодов.

А, вот и печатная плата!

На этом рисунке изображена печатная плата блока питания с регулировкой тока и напряжения от 2.4В до 28В 30А

Печатная плата блока питания с регулировкой тока и напряжения от 2.4В до 28В 30А

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Печатную плату вы можете изготовить с помощью лазерно утюжной технологии для продвинутых, а также навесным монтажом этот способ больше подходит для начинающих радиолюбителей и они о нем прекрасно знают. Для изготовления печатной платы вам понадобиться фольгированный стеклотекстолит размером 100х83 мм. Большинство деталей устанавливаются на печатной плате за исключением транзисторов Т2, Т3, Т4, Т5, а также стабилизатор напряжения L7812CV и резисторы R2, R3, Р1, Р2. Биполярные транзисторы Т2 и Т3 устанавливаются на отдельном радиаторе без изоляционных прокладок, потому, что коллекторы транзисторов все равно по схеме соединяются вместе. Полевые транзисторы Т4, Т5 надо тоже установить на отдельном радиаторе без изоляции.

На этом рисунке изображены два радиатора с установленными транзисторами. Между собой радиаторы скреплены двумя лентами двухстороннего автомобильного скотча выполняющего роль электро изоляции. Сверху к радиаторам прикручена винтами пластиковая скрепляющая пластина, придающая жесткость конструкции. К ней будет крепиться дополнительная пластина с печатной платой и вентилятор.

Поскольку уравнительные резисторы R2 и R3 довольно большого размера для их предусмотрена специальная печатная плата, которая изображена на этом рисунке. Размер печатной платы 85х40 мм.

Печатная плата блока резисторов

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Стабилизатор напряжения L7812CV надо закрепить на отдельный радиатор от компьютерного блока питания, потому, что в процессе работы он сильно нагревается. На этой картинке он находится в самом низу на радиаторе от компьютерного блока питания. С правой стороны вы увидите плату с уравнительными резисторами R2 и R3. Транзистор Т1 установлен на маленький радиатор. Переменные резисторы Р1 и Р2 тоже вынесены на верхнюю панель. Диодная сборка установлена на отдельном радиаторе, при большой нагрузке она очень сильно греется.

Для охлаждения радиаторов к установленному в блоке питания стабилизатору напряжения L7812CV я подключил вентилятор размером 120х120 мм, он отлично справляется со своей задачей.

Если вы хотите подключить вентилятор от дополнительной обмотки трансформатора, тогда вам надо поставить дополнительный стабилизатор напряжения по этой схеме.

Схема подключения вентилятора

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Как подключить Китайский вольтметр амперметр?

При подключении Китайских электронных вольтметров амперметров возникает очень много различных проблем, то показания скачут, то завышает, то занижает, кому то бракованный прислали, вообщем качество Китайских приборов оставляет желать лучшего. Китайцы продают на АлиЭкспресс две модели чудо приборов. Первая модель имеет два тонких провода красный и черный, три толстых, красный, черный и синий. У второй модели три тонких провода, красный, черный, желтый и два толстых, красный и черный. Чтобы это Китайское чудо правильно работало и не искажало показания, надо знать простое правило, питание у прибора должно быть отдельное потому, что у прибора нет гальванической развязки и поэтому питание на Китайский вольтметр амперметр обязательно надо брать с дополнительной обмотки трансформатора или дополнительного источника питания, для этих целей идеально подойдет зарядка от телефона.

А лучше всего сделать выбор в сторону Китайских стрелочных аналоговых приборов класса точности 2.5. Поставить отдельно вольтметр и амперметр будет намного проще и точнее. Выбор остается за вами.

На этом рисунке изображена схема подключения Китайского вольтметра амперметра.

Схема подключения китайского вольтметра амперметра к блоку питания

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Испытания блока питания

Пришло время испытать блок питания в деле. У микросхемы TL431 есть такая особенность, нижний порог напряжения 2.4 вольта, поэтому в блоке питания напряжение регулируется от 2.4 вольта до 27.4 вольта. Без нагрузки я выставил напряжение 12.5 вольт и подключил галогеновую лампу Н4. Напряжение под нагрузкой упало до 12.3 вольта, просадка составила всего 0.2 вольта при силе тока 4.88 ампера. Это очень хороший результат. Микросхема TL431 прекрасно стабилизирует  напряжение. Как работает ограничение тока смотрите в видеоролике.

Как заряжать автомобильный аккумулятор?

Ну и самое интересное, это использование блока питания в качестве зарядного устройства для автомобильного аккумулятора. При выключенном блоке питания подключаем аккумулятор. Если горит зеленый светодиод, значит все подключено правильно. Что будет если поменять клеймы местами? А, ничего… Просто загорится красный светодиод, означающий ошибку в подключении.

Далее отключаем минусовую клейму, включаем блок питания и выставляем на блоке 14.5 вольт. Подключаем минусовую клейму к аккумулятору. И ручкой регулировки тока выставляем в начале зарядки ток не более 6 ампер для 60 амперного аккумулятора. К концу зарядки ток упадет до 0.1 ампера, а напряжение поднимется до 14.5 вольт. Это будет говорить о том, что аккумулятор полностью заряжен.

Для любителей «чем проще, тем лучше,» предлагаю собрать упрощенную схему блока питания на 15А

Данная схема регулируемого блока питания с регулировкой напряжения и тока рассчитана на максимальный ток до 15А. В ней отсутствуют дополнительные силовые транзисторы и уравнительные резисторы, что немного упрощает схему и делает её более бюджетной по сравнению со схемой на 30А.

Схема блока питания с регулировкой тока и напряжения 2.4…28В 15А

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Печатная плата блока питания с регулировкой тока и напряжения от 2.4В до 28В. Размер платы 100х60 мм.

Печатная плата блока питания с регулировкой тока и напряжения от 2.4В до 28В 15А

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Радиодетали для сборки

Регулируемый блок питания с регулировкой тока и напряжения 30А

• Регулируемый стабилитрон (микросхема) TL431
• Диодный мост на 50А KBPC5010
• Конденсаторы С1, С2 4700 мкФ 50В
• Резисторы R1 1 кОм 5Вт, R2, R3 0.1 Ом 20 Вт, R4 100 Ом, R5, R6 47 Ом, R7, R8 2.7 кОм 0.25Вт, Р1 5 кОм, Р2 1 кОм.
• Радиатор 100х63х33 мм 2шт, радиатор KG-487-17 (HS 077-30) 1шт, радиатор от компьютерного блока питания 1шт
• Стабилизатор напряжения L7812CV
• Транзисторы Т1 TIP41C, КТ805, КТ819, Т2, Т3 TIP35C, КТ 867А, Т4, Т5 IRFP250, IRFP260
• Светодиоды LED1, LED2 на 3В зеленый и красный

Регулируемый блок питания с регулировкой тока и напряжения 15А

• Регулируемый стабилитрон (микросхема) TL431
• Диодный мост на 25А KBPC2510
• Конденсаторы С1, С2 4700 мкФ 50В
• Резисторы R1 1 кОм 5Вт, R2 100 Ом, R3 47 Ом, R4, R5 2.7 кОм 0.25Вт, Р1 5 кОм, Р2 1 кОм.
• Радиатор 100х63х33 мм 1шт, радиатор KG-487-17 (HS 077-30) 1шт, радиатор от компьютерного блока питания 1шт
• Стабилизатор напряжения L7812CV
• Транзисторы Т1 TIP41C, КТ805, КТ819, Т2 TIP35C, КТ 867А, Т3 IRFP250, IRFP260
• Светодиоды LED1, LED2 на 3В зеленый и красный

Чем заменить микросхему TL431?

Аналогом микросхемы TL431 является регулируемый стабилитрон КА431, из советских КР142ЕН19А, К1156ЕР5Х

Друзья, желаю вам удачи и хорошего настроения! До встречи в новых статьях!

Рекомендую посмотреть видеоролик о том, как сделать блок питания с регулировкой тока и напряжения своими руками

Простой регулируемый блок питания 0-30в

Всем давно известно, что без нормального регулируемого блока питания не возможно запустить ни один девайс сделанный своими руками. Ведь блок питания это основа радиолюбительской лаборатории, поэтому в этой статье я расскажу, как сделать простой регулируемый блок питания из доступных деталей всего на двух транзисторах. На этом рисунке изображена простая для изготовления схема регулируемого блока питания.

Схема регулируемого блока питания на транзисторах

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Эта схема очень неприхотлива в радиодеталях по этому, собрать её может каждый начинающий радиолюбитель практически из того, что имеется под рукой. Диодный мост Br1 пойдет практически любой с силой тока не менее 3А. Если нет диодного моста, замените его подходящими диодами. Конденсатор С1 можно заменить любым от 1000 мкФ до 10 000 мкФ. Переменный резистор Р1 от 5 до 10 кОм. Транзистор Т1 КТ815, BD137, BD139 транзистор Т2 КТ805, КТ819, TIP41, MJE13009 и многие другие советские и импортные аналоги, подбираются согласно требуемой нагрузке и мощности источника питания.

Диод D1 с силой тока не менее 3А, можно вообще заменить перемычкой, он защищает конденсатор C2 от переполюсовки при подключении к блоку питания аккумулятора. Источником питания для этой схемы может служить любой трансформатор от 12 до 30 вольт. Для своего блока питания я использовал тороидальный трансформатор от музыкального центра с двумя последовательно соединенными обмотками по 13,5В и силой тока 3,5А. После выпрямления напряжения на выходе получилось 30 вольт.

Все детали блока питания я, как всегда разместил на печатной плате размером 6,5 на 4,5 см. При установке транзисторов обратите внимание на цоколевку. Например у транзистора КТ819 ножки располагаются так ECB, а у транзистора MJE13009 так BCE, по этому транзисторы лучше всего соединить с платой небольшими кусочками провода и тогда у вас не возникнет проблем с правильной установкой транзисторов на радиаторе.

Печатная плата регулируемого блока питания 0-30В

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Два транзистора установите на одном радиаторе без изоляционных прокладок потому, что коллекторы транзисторов на схеме соединяются вместе. Не забудьте места крепления транзисторов смазать термопастой. Диодную сборку желательно закрепить на небольшом радиаторе, она тоже не слабо нагревается. Для контроля выходных характеристик желательно установить универсальный китайский измерительный прибор (УКИП) обозначенный на схеме V/A1.

Все компоненты блока питания я разместил в стандартном корпусе от компьютерного блока питания. Только из за большого размера тороидального трансформатора от музыкального центра вентилятор пришлось разместить снаружи, но это на технические характеристики блока питания особо не влияет.

Благодаря мощному 3,5 амперному тороидальному трансформатору этот универсальный регулируемый блок питания я использую для питания различных самоделок и в качестве зарядного устройства для небольших аккумуляторов.

Друзья, желаю вам удачи и хорошего настроения! До встречи в новых статьях!

Рекомендую посмотреть видеоролик о том как работает регулируемый блок питания.

90000 Designing Power Supply Circuits — Simplest to the Most Complex 90001 90002 The post details how to design and build a good work bench power supply circuit right from the basic design to the reasonably sophisticated power supply having extended features. 90003 90004 Designing a Workbench Power Supply is Indispensable 90005 90002 Whether it’s an electronic noob or an expert engineer, all require this indispensable piece of equipment called the power supply unit. 90003 90002 This is because no electronics can run without power, to be precise a low voltage DC power, and a power supply unit is a device which is specifically meant for fulfilling this purpose.90003 90002 If this equipment is so important, it becomes imperative for all in the field to learn all the nitty-gritties of this important member of the electronic family. 90003 90002 Let’s begin and learn how to design a power supply circuit, a simplest one first, probably for the noobs who would find this information extremely useful. 90013 A basic power supply circuit will fundamentally require three main components for providing the intended results. 90013 A transformer, a diode and a capacitor.The transformer is the device which has two sets of windings, one primary and the other one is the secondary. 90003 90002 Mains 220v or 120v is fed to the primary winding which is transferred to the secondary winding to produce a lower induced voltage there. 90003 90002 The low stepped down voltage available at the secondary of the transformer is used for the intended application in electronic circuits, however before this secondary voltage can be used, it needs to be first rectified, meaning the voltage needs to be made into a DC first.90003 90002 For example if the transfornmer secondary is rated at 12 volts then the acquired 12 volts from the transformer secondary will be a 12 volt AC acros the relevant wires. 90003 90002 Electronic circuit can never work with ACs and therefore this voltage should be transformed into a DC. 90003 90002 A diode is one device which effectively converts an AC to DC, there are three configurations through which basic power supply designs may be configured. 90003 90004 Using a single diode: 90005 90002 The most basic and crude form of power supply design is the one which uses a single diode and a capacitor.Since a single diode will rectify only one half cycle of the AC signal, this type of configuration requires a large output filter capacitor for compensating the above limitation. 90003 90002 A filter capacitor makes sure that after rectification, at the falling or decreasing sections of the resultant DC pattern, where the voltage tends to dip, these sections are filled and topped by the stored energy inside the capacitor. 90003 90002 The above compensation act done by the capacitors stored energy helps to maintain a clean and ripple free DC output which would not be possible just by the diodes alone.90003 90002 For a single diode power supply design, the transformer’s secondary winding just needs to have a single winding with two ends. 90003 90002 However the above configuration can not be considered an efficient power supply design due to its crude half wave rectification and limited output conditioning capabilities. 90003 90004 Using two diodes: 90005 90002 Using a couple of diodes for making a power supply requires a transformer having a center tapped secondary winding. The diagram shows how the diodes are connected to the transformer.90003 90002 Though, the two diodes work in tandem and tackle both the halves of the AC signal and produce a full wave rectification, the employed method is not efficient, because at any instant only one half winding of the transformer is utilized. This results in poor core saturation and unnecessary heating of the transformer, making this type of power supply configuration less efficient and an ordinary design. 90003 90004 Using four diodes: 90005 90002 It’s the best and universally accepted form of power supply configuration as far as the rectification process is concerned.90003 90002 The clever use of four diodes makes things very simple, only a single secondary winding is all that is required, the core saturation is perfectly optimized resulting in an efficient AC to DC conversion. 90003 90002 The figure shows how a full wave rectified power supply is made using four diodes and a relatively low value filter capacitor. 90003 90002 This type of diode configuration is popularly know as the bridge network, you may want to know how to construct a bridge rectifier.90003 90002 All the above power supply designs provide outputs with ordinary regulation and therefore can not be considered perfect, these fail to provide ideal DC outputs, and therefore are not desirable for many sophisticated electronic circuits. Moreover these configurations does not include a variable voltage and current control features. 90003 90002 However the above features may be simply integrated to the above designs, rather with the last full wave power supply configuration through the introduction of a single IC and a few other passive components.90003 90004 Using the IC 317 or LM338: 90005 90002 The IC LM 317 is a highly versatile device which is normally incorporated with power supplies for obtaining well regulated and variable voltage / current outputs. A few power supply example circuits using this IC 90003 90002 Since the above IC can only support a maximum of 1.5 amps, for greater current outputs another similar device but with higher ratings may be used. The IC LM 338 works exactly like the LM 317 but is capable of handling up to 5 amps of current.A simple design is shown below. 90003 90064 90065 90002 For obtaining fixed voltage levels, 78XX series ICs may be employed with the above explained power supply circuits. The 78XX ICs are comprehensively explained for your refernce 90003 90002 Nowadays transformerless SMPS power supplies are becoming the favorites among the users, due to their high efficiency, high power delivering features at amazingly compact sizes. 90013 Though building an SMPS power supply circuit at home is surely not for the novices in the field, engineers and enthusiasts with comprehensive knowledge about the subject can go about building such circuits at home.90003 90002 You can also learn about a neat little switch mode power supply design. 90003 90002 There are a few other forms of power supplies which can be rather built by even the new electronic hobbyists and does not require transformers. Though very cheap and easy to build, these types of power supply circuits can not support heavy current and are normally limited to 200 mA or so. 90003 90075 Transformerless Power Supply Design 90076 90002 Two concepts of the above transformer less type of power supply circuits are discussed in the following couple of posts: 90003 90002 By Using High Voltage Capacitors, 90003 90002 By Using Hi -End ICs and FET 90003 90083 Feedback from One of the Dedicated Readers of this Blog 90084 90002 Dear Swagatam Majumdar, 90003 90002 I wish to make a psu for a micro-controller and its dependent components… 90003 90002 I want to get a stable + 5V out and + 3.3V out from the psu, I’m not sure of the amp-age but I think a 5A total should be enough, there will also be 5V Mouse and 5V Keyboard and 3 x SN74HC595 IC’s too and 2 x 512Kb SRAM … So I really dont know the amp-age to aim for …. 90003 90002 I guess 5Amp is enough? …. My MAIN question is which TRANSFORMER to use and which DIODES to use? I have chosen The transformer after reading somewhere online that the bridge rectifier cause a VOLT DROP of 1.4V in general and in your blog above you state the bridge recitfier will cause the voltage to go up? … 90003 90002 SO I am unsure (I am unsure anyway being new to electronics) ….. The FIRST transformer I chose was this one. Please advise me which one is BEST for my needs and which DIODES to use too …. I would like to use the PSU for a board very similar to this …. 90003 90002 Please help and guide me the best way to make a suitable MAINS 220 / 240V PSU which gives me STABLE 5V and 3.3V for use with my design.Thank You In Advance. 90003 90075 How to Get Constant 5V, and 3V from Power Supply Circuit 90076 90002 Hello, you can achieve that simply through a 7805 IC for getting the 5V and by adding a couple 1N4007 diodes to this 5V for getting approximately 3.3V. 90003 90002 5 amp looks too high and I do not think you would require this much high current unless you are also using this supply with an external driver stage carrying higher loads such as a high watt LED or a motor etc. 90003 90002 So I am sure that your requirement can be easily fulfilled through the above mentioned procedures.90003 90002 for powering MCU through the above procedure you can use a 0-9V or a 0-12V trafo with 1amp current, diodes could be 1N4007 x 4nos 90003 90002 The diodes will drop 1.4V when the input is a DC but when it’s an AC like from a trafo then the output will be raised by a factor of 1.21. 90003 90002 make sure to use a 2200uF / 25V cap after the bridge for the filtration 90003 90002 I hope the info will enlighten you and answer your queries. 90003 90002 The following image shows how to get 5V and 3.3V constant from a given power supply circuit. 90003 90083 Getting 9V variable output from IC 7805 90084 90002 Normally, the IC 7805 is considered as a fixed 5 V voltage regulator device. However, with a basic workaround, the IC could be turned into a 5 V to 9 V variable regulator circuit, as shown above. Here, we can see that a 500 ohm preset is added with the central ground pin of the IC, which allows the IC to produce a lifted output value up to 9 V, with a current of 850 mA. The preset could be adjusted o get outputs in the range of 5 V to 9 V.90003 90075 Making a Fixed 12V Regulator Circuit 90076 90002 In the above diagram we can see how an ordinary 7805 regulator IC could be used for creating a fixed 5V regulated output. 90003 90002 In case you wanted to achieve a fixed 12V regulated power supply, the same configuration could be applied for getting the required results, as shown below: 90003 90075 12V, 5V Regulated Power supply 90076 90002 Now suppose you had circuit applications which needed a dual supply in the range of 12V fixed and also 5V fixed regulated supplies.90003 90002 For such applications the above discussed design could be simply modified by using a 7812 IC and then subsequently a 7805 IC for getting the required 12V and 5V regulated power supply output together, as indicated below: 90003 90083 About Swagatam 90084 90002 I am an electronic engineer (dipIETE), hobbyist, inventor, schematic / PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials.90013 If you have any circuit related query, you may interact through comments, I’ll be most happy to help! 90003.90000 How to Use Resistors with LED, Zener and Transistor 90001 90002 In this post we learn how to use resistors while designing an electronic circuits using LEDs, zener diodes, or transistors. This article can be very useful for the new hobbyists who normally get confused with the resistor values ​​to be used for a specific component and for the desired application. 90003 90004 What is a Resistor 90005 90002 A resistor is a passive electronic component which might look quite unimpressive in a electronic circuit compared to the other active and advanced electronic components such as BJTs, mosfets, ICs, LEDs etc.90003 90002 However contrary to this feeling resistors are one of the most important parts in any electronic circuit and imagining a PCB without resistors may look strange and impossible. 90003 90002 Resistors are basically used for controlling voltage and current in a circuit which becomes highly crucial for operating the various active, sophisticated components. 90003 90002 For example, a BJT such as a BC547 or similar may need a properly calculated resistor across its base / emitter in order to function optimally and safely.90003 90002 If this is not followed, the transistor may simply blow off, and get damaged. 90003 90002 Similarly we have seen how resistors become so essential in circuits which involve ICs such as a 555 or a 741 etc. 90003 90002 In this article we’ll learn how to calculate and use resistors in circuits while designing a particular configuration. 90003 90020 How to use Resistors for driving Transistors (BJTs). 90021 90002 A transistor requires a resistor across its base and emitter and this is the one of the most important relation between these two components.90003 90002 A NPN transistor (BJT) needs a specified amount of current to flow from its base to its emitter rail or ground rail in order to actuate (pass) a heavier load current from its collector to its emitter. 90003 90002 A PNP transistor (BJT) needs a specified amount of current to flow from its emitter or positive rail to its base in order to actuate (pass) a heavier load current from its emitter to its collector. 90003 90002 In order to control the load current optimally, a BJT needs to have a properly calculated base resistor.90003 90002 You may want to see an related example article for making a relay driver stage 90003 90002 The formula for calculating the base resistor of a BJT can be seen below: 90003 90002 90035 R = (Us — 0.6) .Hfe / Load Current, 90036 90003 90002 Where R = base resistor of the transistor, 90039 Us = Source or the trigger voltage to the base resistor, 90039 Hfe = Forward current gain of the transistor. 90003 90002 The above formula will provide with the correct resistor value for operating a load through a BJT in a circuit.90003 90002 Although the above formula may look crucial and imperative for designing a circuit using BJTs and resistors, the results actually need not be so much accurate. 90003 90002 For example suppose we want to drive a 12V relay using a BC547 transistor, if the relay’s operating current is around 30mA, from the above formula, we may calculate the base resistor as: 90003 90002 R = (12 — 0.6). 200 / 0.040 = 57000 ohms that’s equal to 57K 90003 90002 The above value could be assumed to be extremely optimal for the transistor such that the transistor will operate the relay with maximum efficiency and without dissipating or wasting excess current.90003 90002 However practically you would find that in fact any value between 10K and 60k works well for the same implementation, the only marginal drawback being the transistor dissipation which may be slightly more, may be around 5 to 10mA, that’s absolutely negligible and does not matter at all. 90003 90002 The above conversation indicates that although calculating the value of the transistor may be recommended but it’s not entirely essential, as any reasonable value may do the job for you equally well.90003 90002 But that said suppose in the above example if you chose the base resistor below 10K or above 60k, then certainly it would start causing some adverse effects to the results. 90003 90002 Below 10k the transistor would begin getting warmer and dissipating significantly..and above 60K you would find the relay stuttering and not triggering tightly. 90003 90020 Resistors for driving Mosfets 90021 90002 90063 In the above example we noticed that a transistor crucially depends on a decently calculated resistor across its base for executing the load operation correctly.90003 90002 This is because a transistor base is a current dependent device, where the base current is directly proportional to its collector load current. 90003 90002 90035 If the load current is more, the base current will also need to be increased proportionately. 90036 90003 90002 90063 Contrary to this mosfets are entirely different customers. These are voltage dependent devices, meaning a mosfet gate does not depend on current rather on voltage for triggering a load across its drain and source.90003 90002 As long as the voltage at its gate is over or around 9V, the mosfet will fire the load optimally regardless of its gate current which could be as low as 1mA. 90003 90002 Because of the above feature a mosfet gate resistor does not require any crucial calculations. 90003 90002 However the resistor at a mosfet gate must be as low as possible but much greater than a zero value, that is anywhere between 10 and 50 ohms. 90003 90002 Although the mosfet would still trigger correctly even if no resistor was introduced at its gate, a low value is strictly recommended for countering or restricting transients or spikes across the gate / source of the mosfet.90003 90020 90035 Using a resistor with a LED 90036 90021 90002 Just like a BJT, using a resistor with an LED is essential and could be done using the following formula: 90003 90002 90035 R = (Supply voltage — LED fwd voltage) / LED current 90036 90003 90002 Again, the formula results are only for acquiring absolute optimal results from the LED brightness. 90003 90002 For example suppose we have a LED with specs of 3.3V and 20mA. 90003 90002 We want to illuminate this LED from a 12V supply.90003 90002 Using the formula tells us that: 90003 90002 R = 12 — 3.3 / 0.02 = 435 ohms 90003 90002 That implies that a 435 ohm resistor would be required for obtaining the most efficient results from the LED. 90003 90002 However practically you would find that any value between 330 ohm and 1K would render satisfactory results from the LED, so its just about little experience and some practical knowledge and you could easily get across these hurdles even without any calculations. 90003 90020 90035 Using resistors with zener diodes 90036 90021 90002 Many a times we find it essential to include a zener diode stage in an electronic circuit, for example in opamp circuits where an opamp is used like a comparator and we intend to employ a zener diode for fixing a reference voltage across one of the inputs of the opamp.90003 90002 One may wonder how a zener resistor can be calculated ?? 90003 90002 It’s not difficult at all, and is just identical to what we did for the LED in the previous discussion. 90003 90002 That is simply use the following formula: 90003 90002 90035 R = (Supply voltage — Zener voltage) / load current 90036 90003 90002 No need to mention that the rules and parameters are identical as implemented for the LED above, no critical issues will be encountered if the selected zener resistor is slightly less or significantly above the calculated value.90003 90020 90035 How to use Resistors in Opamps 90036 90021 90002 Generally all ICs are designed with high input impedance specs and low output impedance specs. 90003 90002 Meaning, the inputs are well protected from inside and are not current dependent for the operational parameters, but contrary to this the outputs of most IC will be vulnerable to current and short circuits. 90003 90002 Therefore calculating resistors for the input of an IC may not be critical at all, but while configuring the output with a load, a resistor may become crucial and may need to be calculated as explained in our above conversations.90003 90134 90035 Using resistors as current sensors 90036 90137 90002 In the above examples, especially for the LeDs and the BJTs we saw how resistors could be configured as current limiters. Now let’s learn how a resistor may be utilized as a current sensors: 90003 90002 You can also learn the same in this example article which explains how to build current sensing modules 90003 90002 As per Ohms law when current through a resistor is passed, a proportionate amount of potential difference develops across this resistor which can be calculated using the following Ohms law formula: 90003 90002 V = RxI, where V is the voltage developed across the resistor, R is the resistor in Ohms and I is the current passing through the resistor in Amps.90003 90002 Let’s say for example, a 1 amp current is passed through a 2 ohm resistor, solving this in the above formula gives: 90003 90002 V = 2×1 = 2 V, 90003 90002 If the current is reduced to 0.5 amps, then 90003 90002 V = 2×0.5 = 1 V 90003 90002 The above expressions show how the potential difference across the resistor varies linearly and proportionately in response to the flowing current through it. 90003 90002 This property of a resistor is effectively implemented in all current measuring or current protection related circuits.90003 90002 You may see the following examples for studying the above feature of resistors, all these designs have utilized a calculated resistor for sensing the desired current levels for the particular applications .. 90003 90002 Universal High Watt LED Current Limiter Circuit — Constant … 90003 90002 Cheap Current Controlled 12 Volt Battery Charger Circuit … 90003 90002 LM317 as a Variable Voltage Regulator and Variable … 90003 90002 Laser Diode Driver Circuit — Current Controlled | Homemade… 90003 90002 Make a Hundred Watt LED Floodlight Constant Current … 90035 90036 90003 90020 90063 Using resistors as Potential Divider 90021 90002 So far we saw how resistors can be applied in circuits for limiting current, now let us investigate how resistors can be wired for getting any desired voltage level inside a circuit. 90003 90002 Many circuits require precise voltage levels at specific points which become crucial references for the circuit for executing the intended functions.90039 90063 90035 90039 90036 90039 For such applications calculated resistors are used in series for determining the precise voltage levels also called potential differences as per the circuit’s requirement. The desired voltage references are achieved at the junction of the two selected resistors (see figure above). 90003 90002 The resistors which are used for determining specific voltage levels are called potential divider networks. 90003 90002 The formula for finding the resistors and the voltage references can be witnessed below, although it may be also simply achieved using a preset or a pot and by measuring its center lead voltage using a DMM.90003 90002 Vout = V1.Z2 / (Z1 + Z2) 90063 90039 90035 Have further questions? Please jot in your thoughts through your comments. 90036 90003 90134 About Swagatam 90137 90002 I am an electronic engineer (dipIETE), hobbyist, inventor, schematic / PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials. 90039 If you have any circuit related query, you may interact through comments, I’ll be most happy to help! 90003.90000 SMPS Welding Inverter Circuit | Homemade Circuit Projects 90001 90002 If you are looking for an option to replace conventional welding transformer, the welding inverter is the best choice. Welding inverter is handy and runs on DC current. The current control is maintained through potentiometer. 90003 90002 90005 By: Dhrubajyoti Biswas 90006 90003 90008 Using Two Switch Topology 90009 90002 When developing a welding inverter, I applied forward inverter with two switches topology. Here the input line voltage traverses through the EMI filter further smoothing with big capacity.90003 90002 However, as the switch-on current pulse tends to be high there needs the presence of softstart circuit. As the switching is ON and the primary filter capacitors charges via resistors, the power is further zeroed by turning the switching ON the relay. 90003 90002 The moment the power is switched, the IGBT transistors gets used and are further applied through TR2 forward gate drive transformer followed by shaping the circuit with the help of IC 7812 regulators. 90003 90016 Using IC UC3844 for PWM Control 90017 90002 The control circuit used in this scenario is UC3844, which is very much similar to UC3842 with pulse-width limit to 50% and working frequency to 42 kHz.90003 90002 The control circuit draws the power from an auxiliary supply of 17V. Due to high currents, the current feedback uses Tr3 transformer. 90003 90002 The voltage of 4R7 / 2W sensing register is more or less equal to the current output. The output current can be further controlled by P1 potentiometer. Its function is to measure the feedback’s threshold point and the threshold voltage of pin 3 of UC3844 stands at 1V. 90003 90002 One important aspect of power semiconductor is that it needs cooling and most of the heat generated is pushed out in output diodes.90003 90002 The upper diode which consists of 2x DSEI60-06A should have the capacity to handle the current at an average of 50A and loss till 80W. 90003 90002 The lower diode i.e. STTh300L06TV1 also should the average current of 100A and loss till 120W. On the other hand, the total max loss of the secondary rectifier is 140W. The L1 output choke is further connected with the negative rail. 90003 90002 This is a good scenario since the heat sink is barred from hi-frequency voltage. Another option is to use FES16JT or MUR1560 diodes.90003 90002 However, it is important to consider that the max current flow of the lower diode is twice the current to that of the upper diode. 90003 90016 Calculating IGBT Loss 90017 90002 As a matter of fact, calculating IGBT’s loss is a complex procedure since besides conductive losses switching loss is another factor too. 90003 90002 Also each transistor loses around 50W. The rectifier bridge also loses power till 30W and it is placed on the same heat sink as IGBT along with UG5JT reset diode.90003 90002 There is also the option to replace UG5JT with FES16JT or MUR1560. The loss of power of the reset diodes is also dependent upon the way Tr1 is constructed, albeit the loss is lesser compared to the loss of power from IGBT. The rectifier bridge also accounts to power loss of around 30W. 90003 90002 Furthermore when preparing the system it is important to remember to scale the maximum loading factor of the welding inverter. Based upon the measurement, you can then be ready to select the correct size of the winding gauge, heat sink etc.90003 90002 Another good option is to add a fan as this will keep a check on the heat. 90003 90016 Circuit Diagram 90017 90016 Transformer Winding Details 90017 90002 The Tr1 switching transformer is wounded two ferrite EE core and they both have the central column section of 16x20mm. 90003 90002 Therefore, the total cross section calculates to 16x40mm. Care should be taken to leave no air gap in the in the core area. 90003 90002 A good option would be to use 20 turns primary winding by wounding it with 14 wires of 0.5mm diameter. 90003 90002 The secondary winding on the other hand has six copper strip of 36×0.55mm. The forward drive transformer Tr2, which is designed on low stray inductance, follows trifillar winding procedure with three twisted insulated wire of 0.3 mm diameter and the windings of 14 turns. 90003 90002 The core section is made of h32 with the middle column diameter of 16mm and leaving no gaps. 90003 90002 The current transformer Tr3 is made of EMI suppression chokes. While the primary has only 1 turn, the secondary is wounded with 75 turns of 0.4 mm wire. 90003 90002 One important issue is to keep the polarity of the windings. While L1 has ferrite EE core, the middle column has the cross section of 16x20mm having 11 turns of copper strip of 36×0.5mm. 90003 90002 Furthermore, the total air gap and the magnetic circuit are set to 10mm and its inductance is 12uH cca. 90003 90002 The voltage feedback does not really hamper the welding, but it surely affects the consumption and the loss of heat when in idle mode. The use of voltage feedback is quite important because of high voltage of around 1000V.90003 90002 Moreover, the PWM controller is operating at max duty cycle, which increases the power consumption rate and also the heating components. 90003 90002 The 310V DC could be extracted from the grid mains 220V after rectification via a bridge network and filtration through a couple of 10uF / 400V electrolytic capacitors. 90003 90002 The 12V supply could be obtained from a ready-made 12V adapter unit or built at home with the help of the info provided 90073 here 90074: 90003 90008 Aluminum Welding Circuit 90009 90002 This request was submitted to me by one of the dedicated readers of this blog Mr.Jose. Here are the details of the requirement: 90003 90080 90002 My welding machine Fronius-TP1400 is fully functional and I have no interest in changing its configuration. This machine that has an age is the first generation of inverter machines. 90003 90002 It is a basic device for welding with coated electrode (MMA welding) or tungsten arc gas (TIG welding). A switch allows the choice. 90003 90002 This device only provides DC current, this is very appropriate for a large number of metals to be welded.90003 90002 There are a few metals such as aluminum that due to its rapid corrosion in contact with the environment, it is necessary to use pulsating AC current (square wave 100 to 300 Hz) this facilitates the elimination of corrosion in cycles with inverted polarity and turn the melting in the direct polarity cycles. 90003 90002 There is a belief that aluminum does not oxidize, but it is incorrect, what happens is that at the zero moment that it receives contact with air, a thin layer of oxidization is produced, and which from then on preserves it from next subsequent oxidization.This thin layer complicates the work of welding that’s why AC current is used. 90003 90002 My desire is make a device that be connected it betwen the terminals of my DC welding machine and the Torch to obtain that AC current in the Torch. 90003 90002 This is where I have difficulties, at the moment of building that CC to AC converter device. I am fond of electronics but not expert. 90003 90002 So I understand the theory perfectly, I look at the HIP4080 IC or similar datasheet seeing that it is possible to apply it to my project.90003 90002 But my great difficulty is that I do not do the necessary calculation of the values ​​of the components. Maybe there is some scheme that can be applied or be adapted, I not find it on internet and I do not know where to look, that’s why I ask for your help. 90003 90099 90002 90101 The Design 90102 90003 90002 In order ensure that the welding process is able to eliminate the oxidized surface of an aluminum and enforce an effective welding joint, the existing welding rod and the aluminum plate could be integrated with a full bridge driver stage , as shown below: 90003 90002 The Rt, Ct could be calculated with some trial and error to get the mosfets oscillating at any frequency between 100 and 500Hz.For the exact formula you could refer to this article. 90003 90002 Th 15V input could be supplied from any 12V or 15V AC to DC adapter unit. 90003 90110 About Swagatam 90111 90002 I am an electronic engineer (dipIETE), hobbyist, inventor, schematic / PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials. 90113 If you have any circuit related query, you may interact through comments, I’ll be most happy to help! 90003.90000 7 Simple Inverter Circuits you can Build at Home 90001 90002 These 7 inverter circuits may look simple with their designs, but are able to produce a reasonably high power output and an efficiency of around 75%. Learn how to build this cheap mini inverter and power small 220V or 120V appliances such drill machines, LED lamps, CFL lamps, hair dryer, mobile chargers, etc through a 12V 7 Ah battery. 90003 90004 What is a Simple Inverter 90005 90002 An inverter which uses minimum number of components for converting a 12 V DC to 230 V AC is called a simple inverter.A 12 V lead acid battery is the most standard form of battery which is used for operating such inverters. 90003 90002 Let’s begin with the most simplest in the list which utilizes a couple of 2N3055 transistors and some resistors. 90003 90004 1) Simple Inverter Circuit using Cross Coupled Transistors 90005 90002 The article deals with the construction details of a mini inverter. Read to know regrading the construction procedure of a basic inverter which can provide reasonably good power output and yet is very affordable and sleek.90003 90002 There may be a huge number of inverter circuits available over the internet and electronic magazines. But these circuits are often very complicated and hi-end type of inverters. 90003 90002 Thus we are left with no choice but just to wonder how to build power inverters that can be not only easy to build but also low cost and highly efficient in its working. 90003 90018 12v to 230v inverter circuit diagram 90019 90002 Well your search for such a circuit ends here. The circuit of an inverter described here is perhaps the smallest as far its component count goes yet is powerful enough to fulfill most of your requirements.90003 90004 Construction Procedure 90005 90002 To begin with, first make sure to have proper heatsinks for the two 2N3055 transistors. It can be fabricated in the following manner: 90003 90026 90027 Cut two sheets of aluminum of 6/4 inches each. 90028 90029 90026 90027 Bend one end of the sheet as shown in the diagram. Drill appropriate sized holes on to the bends so that it can be clamped firmly to the metal cabinet. 90028 90027 If you find it difficult to make this heatsink you can simply purchase from your local electronic shop shown below: 90028 90029 90026 90027 Also drill holes for fitting of the power transistors.The holes are 3mm in diameter, TO-3 type of package size. 90028 90027 Fix the transistors tightly on to the heatsinks with the help of nuts and bolts. 90028 90027 Connect the resistors in a cross-coupled manner directly to the leads of the transistors as per the circuit diagram. 90028 90027 Now join the heatsink, transistor, resistor assembly to the secondary winding of the transformer. 90028 90027 Fix the whole circuit assembly along with the transformer inside a sturdy, well ventilated metal enclosure.90028 90027 Fit the output and input sockets, fuse holder etc. externally to the cabinet and connect them appropriately to the circuit assembly. 90028 90029 90002 Once the above heatsink installation is over, you simply need to interconnect a few high watt resistors and the 2N3055 (on heatsink) with the selected transformer as given in the following diagram. 90003 90018 Complete Wiring Layout 90019 90002 After the above wiring is completed, it’s time to hook it up with a 12V 7Ah battery, with a 60 watt lamp attached at the transformer secondary.When switched ON the result would be an instant illumination of the load with an astonishing brightness. 90003 90002 Here the key element is the transformer, make sure the transformer is genuinely rated at 5 amp, otherwise you may find the output power a lot lesser than the expectation. 90003 90002 I can tell this from my experience, I built this unit twice, once when I was in college, and the second time recently in the year 2015. Although I was more experienced during the recent venture I could not get the awesome power that I had acquired from my previous unit.The reason was simple, the previous transformer was a robust custom built 9-0-9V 5 amp transformer, compared to the new one in which I had used probably a falsely rated 5 amp, which was actually only 3 amp with its output. 90003 90018 Parts List 90019 90002 You will require just the following few components for the construction: 90003 90026 90027 R1, R2 = 100 OHMS./ 10 WATTS WIRE WOUND 90028 90027 R3, R4 = 15 OHMS / 10 WATTS WIRE WOUND 90028 90027 T1, T2 = 2N3055 POWER TRANSISTORS (MOTOROLA).90028 90027 TRANSFORMER = 90072 9- 0- 9 VOLTS 90073/8 AMPS or 5 amps. 90028 90027 AUTOMOBILE BATTERY = 12 VOLTS / 10Ah 90028 90027 ALUMINUM HEATSINK = CUT AS PER THE REQUIRED SIZE. 90028 90027 VENTILATED METAL CABINET = AS PER THE SIZE OF THE WHOLE ASSEMBLY 90028 90029 90018 Video Test Proof 90019 90002 90085 90086 90003 90018 How to Test it? 90019 90026 90027 The testing of this mini inverter is done in the following method: 90028 90027 For testing purpose connect a 60 watt incandescent bulb to the output socket of the inverter.90028 90027 Next, connect a fully charged 12 V automobile battery to its supply terminals. 90028 90027 The 60 watt bulb should immediately light up brightly, indicating that the inverter is functioning properly. 90028 90027 This concludes the construction and the testing of the inverter circuit. 90028 90027 I hope from the above discussions you must have clearly understood how to build an inverter which is not only simple to construct but also very affordable to each of you. 90028 90027 It can be used to power small electrical appliances like soldering iron, CFL lights, small portable fans etc.The output power will lie in the vicinity of 70 watts and is load dependent. 90028 90027 The efficiency of this inverter is around 75%. The unit may be connected to your vehicles battery itself when outdoors so that the trouble of carrying an extra battery is eliminated. 90028 90029 90018 Circuit Operation 90019 90002 The functioning of this mini inverter circuit is rather unique and different from the normal inverters which involve discrete oscillator stage for powering the transistors. 90003 90002 However here the two sections or the two arms of the circuit operate in a regenerative manner.Its very simple and may be understood through the following points: 90003 90002 The two halves of the circuit no matter how much they are matched will always consist a slight imbalance in the parameters surrounding them, like the resistors, Hfe, transformer winding turns etc. 90003 90002 Due to this, both the halves are not able to conduct together at one instant. 90003 90002 Assume that the upper half transistors conduct first, obviously they will be getting their biasing voltage through the lower half winding of the transformer via R2.90003 90002 However the moment they saturate and conduct fully, the entire battery voltage is pulled through their collectors to the ground. 90003 90002 This sucks-out dry any voltage through R2 to their base and they immediately stop conducting. 90003 90002 This gives an opportunity for the lower transistors to conduct and the cycle repeats. 90003 90002 The whole circuit thus starts to oscillate. 90003 90002 The base Emitter resistors are used to fix a particular threshold for their conduction to break, they help to fix a base biasing reference level.90003 90002 The above circuit was inspired from the following design by Motorola: 90003 90132 90002 90072 UPDATE: You may also want to try this: 50 watt Mini Inverter Circuit 90073 90003 90132 90002 Output Waveform better than square wave (Reasonably suitable for all electronic appliances )) 90003 90140 90141 PCB Design for the above explained simple 2N3055 Inverter Circuit (Track Side Layout) 90142 90004 2) Using IC 4047 90005 90002 As shown above a simple yet useful little inverter can be built using just a single IC 4047.The IC 4047 is a versatile single IC oscillator, which will produce precise ON / OFF periods across its output pin # 10 and pin # 11. The frequency here could be determined by accurately calculating the resistor R1 and capacitor C1. These components determine the oscillation frequency at the output of the IC which in turn sets the output 220V AC frequency of this inverter circuit. It may set at 50Hz or 60Hz as per individual preference. 90003 90002 The battery, mosfet and the transformer can be modified or upgraded as per the required output power specification of the inverter.90003 90002 For calculating the RC values, and the output frequency please refer to the datasheet of the IC 90003 90141 90072 Video Test Results 90073 90142 90002 90156 90086 90003 90018 3) Using IC 4049 90019 IC 4049 pin details 90002 In this simple inverter circuit we use a single IC 4049 which includes 6 NOT gates or 6 inverters inside. In the diagram above N1 —- N6 signify the 6 gates which are configured as oscillator and buffer stages. The NOT gates N1 and N2 are basically used for the oscillator stage, the C and R can be selected and fixed for determining the 50Hz or 60 Hz frequency as per country specs 90003 90002 The remaining gates N3 to N6 are adjusted and configured as buffers and inverters so that the ultimate output results in producing alternating switching pulses for the power transistors.The configuration also ensures that no gates are left unused and idle, which may otherwise require their inputs to be terminated separately across a supply line. 90003 90002 The transformer and battery may be selected as per the power requirement or the load wattage specifications. 90003 90002 The output will be purely a square wave output. 90003 90002 90072 Formula for calculating frequency is given as: 90073 90003 90002 90072 f = 1 /1.2RC, 90073 90003 90002 where R will be in Ohms and F in Farads 90003 90004 4) Using IC 4093 90005 IC 4093 pin details 90002 Quite similar to the previous NOT gate inveter, the NAND gate based simple inverter shown above can be built using a single 4093 IC.The gates N1 to N4 signify the 4 gates inside the IC 4093. 90003 90002 N1, is wired as an oscillator circuit, for generating the required 50 or 60Hz pulses. These are appropriately inverted and buffered using the remaining gates N2, N3, N4 in order to finally deliver the alternately switching frequency across the bases of the power BJTs, which in turn switch the power transformer at the supplied rate for generating the required 220V or 120V AC at the output. 90003 90002 Although any NAND gate IC would work here, using the IC 4093 is recommended since it features Schmidt trigger facility, which ensures a slight lag in switching and helps creating a kind of dead-time across the switching outputs, making sure that the power devices are never switched ON together even for a fraction of a second.90003 90004 5) Another Simple NAND gate Inverter using MOSFETs 90005 90002 Another simple yet powerful inverter circuit design is explained in the following paragraphs which can be built by any electronic enthusiast and used for powering most of the household electrical appliances (resistive and SMPS loads) . 90003 90002 The use of a couple of mosfets influences a powerful response from the circuit involving very few components, however the square wave configuration does limit the unit from quite a few useful applications.90003 90018 Introduction 90019 90002 Calculating MOSFET parameters may seem to involve a few difficult steps, however by following the standard design enforcing these wonderful devices into action is definitely easy. 90003 90002 When we talk about inverter circuits involving power outputs, MOSFETs imperatively become a part of the design and also the main component of the configuration, especially at the driving output ends of the circuit. 90003 90002 Inverter circuits being the favorites with these devices, we would be discussing one such design incorporating MOSFETs for powering the output stage of the circuit.90003 90002 Referring to the diagram, we see a very basic inverter design involving a square wave oscillator stage, a buffer stage and the power output stage. 90003 90002 The use of a single IC for generating the required square waves and for buffering the pulses particularly makes the design easy to make, especially for the new electronic enthusiast. 90003 90018 Using IC 4093 NAND Gates for the Oscillator Circuit 90019 90002 The IC 4093 is a quad NAND gate Schmidt Trigger IC, a single NAND is wired up as an astable multivibrator for generating the base square pulses.The value of the resistor or the capacitor may be adjusted for acquiring either a 50 Hz or 60 Hz pulses. For 220 V applications 50 Hz option needs to be selected and a 60 Hz for the 120 V versions. 90003 90002 The output from the above oscillator stage is tied with a couple of more NAND gates used as buffers, whose outputs are ultimately terminated with the gate of the respective MOSFETs. 90003 90002 The two NAND gates are connected in series such that the two mosfets receive opposite logic levels alternately from the oscillator stage and switch the MOSFETs alternately for making the desired inductions in the input winding of the transformer.90003 90018 Mosfet Switching 90019 90002 The above switching of the MOSFETs stuffs the entire battery current inside the relevant windings of the transformer, inducing an instant stepping up of the power at the opposite winding of the transformer where the output to the load is ultimately derived. 90003 90002 The MOSFETs are capable of handling more than 25 Amps of current and the range is pretty huge and therefore becomes suitable driving transformers of different power specs. 90003 90002 It’s just a matter of modifying the transformer and the battery for making inverters of different ranges with different power outputs.90003 90141 Parts List for the above explained 150 watt inverter circuit diagram: 90142 90026 90027 R1 = 220K pot, needs to be set for acquiring the desired frequency output. 90028 90027 R2, R3, R4, R5 = 1K, 90028 90027 T1, T2 = IRF540 90028 90027 N1-N4 = IC 4093 90028 90027 C1 = 0.01uF, 90028 90027 C3 = 0.1uF 90028 90029 90002 TR1 = 0-12V input winding , current = 15 Amp, output voltage as per the required specs 90003 90002 90072 Formula for calculating frequency will be identical to the one described above for IC 4049.90073 90003 90002 f = 1 /1.2RC. where R = R1 set value, and C = C1 90003 90004 6) Using IC 4060 90005 90002 If you have a single 4060 IC in your electronic junk box, along with a transformer and a few power transistors, you are probably all set to create your simple power inverter circuit using these components. The basic design of the proposed IC 4060 based inverter circuit can be visualized in the above diagram. The concept is basically the same, we use the IC 4060 as an oscillator, and set its output to create alternately switching ON OFF pulses through an inverter BC547 transistors stage.90003 90002 Just like IC 4047, the IC 4060 requires an external RC components for setting up its output frequency, however, the output from the IC 4060 are terminated into 10 individual pinouts in a specific order wherein the output generate frequency at a rate twice that of its preceding pinout. 90003 90002 Although you may find 10 separate outputs with a rate of 2X frequency rate across the IC output pinouts, we have selected the pin # 7 since it delivers the fastest frequency rate among the rest and therefore may fulfil this using standard components for the RC network, which may be easily available to you no matter in which part of the globe you are situated in.90003 90002 90072 For calculating the RC values ​​for R2 + P1 and C1 and the frequency you can use the formula as described below: 90073 90003 90002 Or another way is through the following formula: 90003 90002 90072 f (osc) = 1 / 2.3 x Rt x Ct 90073 90003 90002 Rt is in Ohms, Ct in Farads 90003 90002 More info can be obtained from this article 90003 90002 Here’s yet another cool DIY inverter idea which is extremely reliable and uses ordinary parts for accomplishing a high power inverter design, and can be upgraded to any desired power level.90003 90002 Let’s learn more about this simple design 90003 90004 7) Simplest 100 Watt Inverter for the Newcomers 90005 90002 The circuit of a simple 100 watt inverter discussed in this article can be considered as the most efficient, reliable, easy to build and powerful inverter design. It will convert any 12V to 220V effectively using minimum components 90003 90018 Introduction 90019 90002 The idea was published many years back in one of the elecktor electronics magazines, I present it here so that you all can make and use this circuit for your personal applications.Let’s learn more. 90003 90002 The proposed simple 100 watt inverter circuit disign was published quite a long time ago in one of the elektor electronics magazines and according to me this circuit is one of the best inverter designs you can get. 90003 90002 I consider it to be the best because the design is well balanced, well calculated, utilizes ordinary parts and if done everything correctly would start working instantly. 90003 90002 The efficiency of this design is in the vicinity of 85% that’s good considering the simple format and low costs involved.90003 90018 Using an Transistor Astable as the 50Hz Oscillator 90019 90002 Basically the whole design is built around an astable multivibrator stage, consisting of two low power general purpose transistors BC547 along with the associated parts consisting of two electrolytic capacitors and some resistors. 90003 90002 This stage is responsible for generating the basic 50 Hz pulses required for initiating the inverter operations. 90003 90002 The above signals are at low current levels and therefore requires to be lifted to some higher orders.This is done by the driver transistors BD680, which are Darlington by nature. 90003 90002 These transistors receive the low power 50 Hz signals from the BC547 transistor stages and lift them at higher current levels so that it can be fed to the output transistors. 90003 90002 The output transistors are a pair of 2N3055 which receive an amplified current drive at their bases from the above driver stage. 90003 90018 2N3055 Transistors as the Power Stage 90019 90002 The 2N3055 transistors thus are also driven at high saturation and high current levels which gets pumped into the relevant transformer windings alternately, and converted into the required 220V AC volts at the secondary of the transformer.90003 90141 Parts List for the above explained simple 100 watt inverter circuit 90142 90026 90027 R1, R2 = 27K, 1/4 watt 5% 90028 90027 R3, R4, R5, R6 = 330 OHMS, 1/4 watt 5% 90028 90027 R7 , R8 = 22 OHMS, 5 WATT WIRE WOUND TYPE 90028 90027 C1, C2 = 470nF 90028 90027 T1, T2 = BC547, 90028 90027 T3, T4 = BD680, OR TIP127 90028 90027 T5, T6 = 2N3055, 90028 90027 D1, D2 = 1N5402 90028 90027 TRANSFORMER = 9-0-9V, 5 AMP 90028 90027 BATTERY = 12V, 26AH, 90028 90029 90018 Heatsink for the T3 / T4, and T5 / T6 90019 90002 90072 Specifications: 90073 90003 90331 90027 Power Output: 100 watts if single 2n3055 transistors are used on each channels.90028 90027 Frequency: 50 Hz, Square Wave, 90028 90027 Input Voltage: 12V @ 5 Amps for 100 Watts, 90028 90027 Output Volts: 220V or 120V (with some adjustments) 90028 90340 90002 From the above discussion you might be feeling thoroughly enlightened regarding how to build these 7 simple inverter circuits, by configuring a given basic oscillator circuit with a BJT stage and a transformer, and by incorporating very ordinary parts which may be already existing with you or accessible by salvaging an old assembled PC board.90003 90141 How to Calculate the Resistors and Capacitors for 50 Hz or 60 Hz Frequencies 90142 90002 In this transistor based inverter circuit, the oscillator design is built using a transistorized astable circuit. 90003 90002 Basically the resistors and capacitors associated with the bases of the transistors determine the frequency of the output. Although these are correctly calculated to produce approximately 50 Hz frequency, if you are further interested to tweak the output frequency as per own preference you can easily do so by calculating them through this 90072 Transistor Astable Multivibrator Calculator.90073 90003 90018 Universal Push-Pull Module 90019 90002 If you are interested to achieve a more compact an efficient design using a simple a 2 wire transformer push pull configuration, then you can try the following couple of concepts 90003 90002 The first one below uses the IC 4047, along with a couple of p channel and n channel MOSFETs: 90003 90002 If you wish to employ some other oscillator stage as per your preference, in that case you can apply the following universal design. 90003 90002 This will allow you to integrate any desired oscillator stage and get the required 220 V push pull output.90003 90002 Moreover it also has an integrated auto-changeover battery charger stage. 90003 90018 Advantages of Simple Push-Pull Inverter 90019 90002 The main advantages of this universal push-pull inverter design are: 90003 90026 90027 It uses a 2 wire transformer, which makes the design highly efficient, in terms of size and power output. 90028 90027 It incorporates a changeover with battery charger, which charges the battery when the mains is present, and during a mains failure changes over to inverter mode using the same battery to produce the intended 220 V from the battery.90028 90027 It uses ordinary p-channel and N-channel MOSFETs without any complex circuitry. 90028 90027 It is cheaper to build and more efficient than the center tap counterpart. 90028 90029 90072 UNIVERSAL PUSH PULL MOSFET MODULE WHICH WILL INTERFACE WITH ANY DESIRED OSCILLATOR CIRCUIT 90073 90018 For the Advanced Users 90019 90002 The above explained were a few straightforward inverter circuit designs, however if you think these are pretty ordinary for you, you can always explore more advanced designs which are included in this website.Here are a few more links for your reference: 90003 90132 90002 90072 More Inverter Projects for You with Full online Help! 90073 90003 90132 90141 About Swagatam 90142 90002 I am an electronic engineer (dipIETE), hobbyist, inventor, schematic / PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials. 90392 If you have any circuit related query, you may interact through comments, I’ll be most happy to help! 90003.