The ic has time dependent current limiting, thermal regulation and is available in 3 lead transistor package. We have 78xx 7805, 7806, 7812 etc series voltage regulators for positive power supply and 79xx for negative power supply. The circuit it uses known completed that is capable gives in the his exit, current in continuous operation 5a and 12a peak current. Dc circuit, electronics projects, shop layout, technology, labrador, audio, pdf. Above 15v differential, power dissipation is limited by internal protection circuitry. Power supply a device that provides electrical or other types of energy to an output load, and are capable of converting some other form of energy into electricity such as generators, fuel cells, and solar power.
Add a 350ma load and the power supply voltage slowly drops down and then out. Lm338 5a, 40v, lowiq, adjustable linear voltage regulator. I had thought that using a laptop power supply would have made more sense than a wall wart given the requirements of the laptop. That is why power supplies and voltage stabilizers are one of the most popular topics, enjoying uninterrupted interest. Mar 30, 2020 here is the lm338 adjustable dc power supply circuit, 1. In this tutorial ill show you how i built an lm317 linear positive regu. This simple power supply is built around the lm317lm338lm350 linear voltage regulator. The first working mode 220v ac current reveled by t1 to 30vac then rectified by four diodes d1,d2,d3. The circuit was designed based on two types of voltage regulator which utilizes three lm338 to produce a maximum 25v at 15a and one lm350 to produce a maximum of 25v at 3a terminology lm338 an adjustable 3terminal positive voltage regulator capable of supplying in excess of 5a used as battery chargers, constant current regulators, and. But motors like servo motors or pmdc motors which run on 12v or more, require a high current. Problem with voltage regulator lm338 electronics forum. Best dc power supply adjustable voltage to and, using and if you are looking for simple dual variable power supply. Using lm317 or lm338 as adjustable current limiter for atx lab power supply. Careful circuit design has resulted in outstanding load and line regulation comparable to many commercial power supplies.
Variable power supply circuit from fixed voltage regulator. Hi, i built a standard power supply from the datasheet for a lm338 regulator. This project provides a variable output voltage ranging from 1. When using lm338, i can get voltages ranging from 1. The meter is a perfect addition to any power supply, battery chargers and other electronic projects where voltage and current must be monitored. Lm338 adjustable power supply circuit electronics projects.
This kind of dc power supplies uses a pcb so you can use two case. Please practice handwashing and social distancing, and check out our resources for adapting to these times. Variable power supply kit is good soldering techniques. Lm8 lm338 5amp adjustable regulators datasheet catalog. Lm317 circuits projects 12 browse through a total of 12 lm317 circuits projects. It will deliver up to 600ma of current with current limiting. From all principles above, we have circuits applications, as shown in figure 4, if you want to add the iclm338, enabling them to be higher current for a transformer that can supply at least 30 amperes, and voltage secondary coil, should not be less than 18 volts. This v5a power supply is based on the famous lm338 ic from the st microelectronics. Lm317 lm338 lm350 voltage regulator calculator and. The problem im observing is very large voltage drop under load. The lm8 is rated for t j 55c to 150c, and the lm338 is rated for t j 0c to 125c. The main category is power supply projects that is about power supply projects and modifications for ham radio.
The circuit it uses known completed that is capable gives in the his exit. Dc power supply is often required to power electronic devices. Ic lm338 application circuits homemade circuit projects. Careful circuit design has resulted in outstanding load and line regulation comparable to many commercial power supplies the lm8 family is supplied in a.
So we are building here the regulated power supply of 3a current with the variable voltage between 0 to 24v. Lm338 datasheet, lm338 pdf, lm338 data sheet, lm338 manual, lm338 pdf, lm338, datenblatt, electronics lm338, alldatasheet, free, datasheet, datasheets, data sheet. After many years of employing this ugly and clumsy bench power supply, i decided it was time to build something better, smaller, and well prettier. Hello, i have problem with a voltage regulator lm338.
The presented power supply is an application of the popular lm338 regulator ic, which housed practically all elements of the high voltage regulator lm338. From all principles above, we have circuits applications, as shown in figure 4, if you want to add the ic lm338, enabling them to be higher current for a transformer that can supply at least 30 amperes, and voltage secondary coil, should not be less than 18 volts. I am building two of these, with one slotting into my main power station, the powerstation2. Circuit projects lm338 and lm350 dual power supply. High power dc regulator 420 volts 20 amps by lm338. Now that our display is ready let us start with the other circuits. Now, i also added a lm338 in series as an adjustable current limiter simpler version of the circuit mentioned by armandas, but the fact is that it uses a. I needed a simple power supply to power micro and op amp projects. Jan 22, 2016 variable power supply circuit from fixed voltage regulator. Lm338 datasheet adjustable power supply 5a and 10a elec.
The main advantage of this added complexity is that switched mode operation gives regulated dc supplies that can deliver more power for a given size, cost and weight of power unit. About lm338 power supply project the resource is currently listed in in a single category. While some require a regulated power supply, there are many applications where the output voltage needs to be varied. Lm338 adjustable power supply circuit publisher electronic circuit. As this is my very first instructable, i hope all of the instructables veterans arent too harsh when it comes to rating this howto. Aug 07, 2019 sir im refering to this first circuit l. The fixed voltage regulator is used to offer fixed voltage at the output terminal and does not depend upon the input voltage supplied. Some assorted useful lm317 application circuits from national semiconductor pdf datasheet has been discretely explained in this chapter through the relevant circuit illustrations. They can be an essential feature for a tight budget individual or company. Variable power supply is the one where we can adjust. Lm338 adjustable power supply 5a power supply circuit, circuit.
The lm317 is one of the most popular voltage regulators on the market, and for good reason. It began as a variable power supply based on an lm338 5a voltage regulator and external power adapter. It began as a variable power supply based on an lm338 5a voltage regulator with. Simple lm317 power supply with current limiting hackaday. The ic can easily supply well over 5a at an output voltage range between 1. In this tutorial we will show you how to get the variable regulated voltage from the lm317 ic. Each one ic lm338 can provide a variable output voltage of 030v and have a current capacity of up to 5a, so that. Types of power supplies elprocus electronic projects for. For most of our sensors and motors we use voltage levels like 3. Lm338 adjustable power supply circuit lm338 power supply. The power supply has a 120 to 28 vac transformer feeding a fullwave. Smps fullbridge pfc 4kva pcb layout pdf 4000w electronics projects, arduino. Using lm317 or lm338 as adjustable current limiter for atx lab power supply page 1. Board is supplied by 25v voltage and may be powered by a battery such as lithium ion cell, two aa cells, external power supply or usb power adapter.
Lm338 adjustable power supply circuit electronics projects circuits stay safe and healthy. The common dc voltages that are required to power up the devices are. Ic lm338 application circuits last updated on june 15, 2019 by swagatam 53 comments in this post we will try to analyze a few interesting ic lm338 based power supply circuits and related application circuits which can used by all hobbyists and professional for their day to day electronic circuits and experiments. Nearly all devices that we use in circuits require a dc source. Unless you change the input capacitorc2 has increased these. The meter uses pic16f876a microcontroller with 16x2 backlighted lcd. Use ic is a voltage regulator designed primarily for series and variable power supply project easy and cheap. Lm338 circuit 1,5v32v 3a s you know, every electronic circuit needs power. Lm317 lm338 lm350 current regulator calculator and. Lm338k is an adjustable 3 terminal positive voltage regulator capable of. I want to get 6v with up to 5a, im using a 15v 5a voltage supply some laptop acdc adapter. Lm338 an adjustable 3terminal positive voltage regulator capable of supplying in excess of 5a used as battery chargers.
Check for continuity using a multimeter every time before you power you circuit. Useful for electronics hobbyists, this linear workbench desktop power supply circuit converts a high input voltage 12v from. Here is the lm338 adjustable dc power supply circuit, 1. The circuit of variable power supply 030v 20a lm338 can provide output voltage can be set for 0 volts dc to 30 volts dc with a current capacity of 20 amperes. Lm8, lm338 snvs771c may 1998revised december 2016 lm8 and lm338 5amp adjustable regulators 1 1 features.
I will explain the circuit step by step as we go through our project. Lm317 lm338 lm350 current regulator calculator and circuits. But what if need to vary the power supply voltage, so here we have variable voltage regulator ic lm317. The circuit of variable power supply 030v 20a lm338 is built using the lm338 ic regulator 4 pieces arranged in parallel. With the advent of chips or ics like lm317, l200, lm338, lm723, configuring power supply circuits with variable voltage output with the above exceptional qualities has become very easy nowadays. Electronics projects, lm338 adjustable power supply circuit power electronic projects, power supply circuit, power supply project, date 20190804. Jun 19, 2018 building 024v 3a variable power supply circuit. Lm338 adjustable power supply circuit electronic circuit. Lcsc electronic components more asian brands, lower prices. It will come in handy to power up many electronic circuits when you are assembling or building any electronic devices. The part numbers in the lm8 series which have a suffix are packaged in a standard steel tocan package, while those with a suffix are packaged in a to220 plastic package. Hi, everyone im new here, and as you are about to see, my nic is pretty apt.
The following circuits show some of the basic uses of the lm317 lm338 lm350 series of voltage regulators when configured as a current regulator or constant current source ccs. The common dc voltages that are required to power up the devices are generally in the range of 3 vdc to 30 vdc. Power dissipation is specified at these values up to 15v inputoutput differential. Lm8 and lm338 5amp adjustable regulators datasheet. Lm338 and lm350 dual power supply circuit wiring diagrams. This is first time when im using a regulated voltage stabiliser. From now it is advisable to proceed with extra caution since we are dealing directly with ac mains and high current. A simple stabilized 9v regulated power supply built with ic 723, 2n3055 and a few external components. Almost all electronic devices used in electronic circuits need a dc source of power to operate. If you want to a lm338 variable dc voltage power supply circuit during 1.
Lm338k is an adjustable 3 terminal positive voltage regulator capable of supplying a maximum of 5a over a 1. I can put other peoples designs together, but ask me to create and i will look very blankly back at you. The transconductance and so essentially the speed of the npn series pass transistor in the lm338 is proportional to its output current, hence the asymmetry. How to use lm317 for making a variable power supply. Devices can be soldered onto the pcb as shown in figure 5. Switched mode designs a number of different design types are used. Look at high current adjustable voltage regulator to or easy and durable circuit.
One of the basic building blocks of electronics project is building your own dc power from an ac source of 110 vac or 220 vac. Build a 5 amp portable power supply with an lm338 regulator. Lm338 datasheet adjustable power supply 5a and 10a. Threeterminal 5 a adjustable voltage regulators stmicroelectronics. The first working mode 220v ac current reveled by t1 to 30vac then rectified by four diodes d1,d2,d3,and d4 and become less than 30vdc. The other one i am using to create a portable power station for my desk.
This project uses a lm338 adjustable 3 terminal regulator to supply a current of up to 5a over a variable output voltage of 2v to 25v dc. For this weeks project i have built a 5 amp variable voltage regulator using an lm338 serial regulator. Ive been using a lm317 circuit to get an 18v dc 1a input down to 9vdc. Volt ampere meter measures voltage of 070v or 0500v with 100mv resolution and current consumption 010a or more with 10ma resolution. Regulated power supplies usually refers to a power supply capable of supplying a variety of output voltages useful for bench testing electronic circuits, possibly with continuous variation of the output voltage, or just some preset voltages. A power supply is unquestionably an absolutely necessary equipment for any electronics lab or anyone who wants to do electronics projects, especially a variable power supply. Using lm317 or lm338 as adjustable current limiter for atx. Jun 15, 2019 ic lm338 application circuits last updated on june 15, 2019 by swagatam 53 comments in this post we will try to analyze a few interesting ic lm338 based power supply circuits and related application circuits which can used by all hobbyists and professional for their day to day electronic circuits and experiments. If you have used lm317 or lm350 they are similar, so easy to use with a few components. Unfortunately the day after that i tried it again but it constantly delivering 42v out, after checking each component i found that the lm338t vout and vin pins are shorted. Unfortunately the day after that i tried it again but it constantly delivering 42v out, after checking each. This link is listed in our web site directory since wednesday sep 9 2015, and till today lm338 power supply project has been followed for a total of 483 times. The ic lm317 promises countless interesting and useful power enhancement circuits, applicable in numerous fields where well dimensioned power supplies become crucially important.
Posted thursday, january 12, 2012 the circuit was designed based on two types of voltage regulator which utilizes three lm338 to produce a maximum 25v at 15a and one lm350 to produce a maximum of 25v at 3a. Variable power supply 030v 20a lm338 electrical note. Also, if anything at all isnt clarified by this howto, please comment with your constructive criticism. Low voltage battery level indicator jim keith 06112014. Here is the circuit producing variable voltage power supply designed using fixed voltage regulators. So to summarise, our bench power supply that we made from an old pc power supply unit in a previous tutorial can be converted to provide a variable voltage power supply by using a lm317t to regulate the voltage. Lm8 and lm338 5amp adjustable regulators datasheet rev. Its a circuit of adjustable 10a regulator, with the ic lm338. From the domestic user point of view, choosing an appropriate power supply is important. The heart of the circuit is a lm338k adjustable voltage regulator ic which is a good quality ic with many built in features like adjustable output, thermal regulation, current limit constant with temperature, short circuit protection etc. How to use lm317 for making a variable power supply circuit. Lm8 lm338 5amp adjustable regulators generaldescription the lm8 series of adjustable 3terminal positive voltage regulators is capable of supplying in excess of 5a over a 12v to 32v output range they are exceptionally easy to use and require only 2 resistors to set the output voltage careful circuit design has resulted in outstanding load and. Lm338 adjustable power supply circuit electronics projects circuits. Lm338 an adjustable 3terminal positive voltage regulator capable of supplying in excess of 5a used as battery chargers, constant current regulators, and adjustable power supplies due to its features such as protected output from short circuit, product enhancement tested, current limit constant with temperature, guaranteed thermal.
Sep 28, 2019 pcb of high power dc regulator420volts20amps. This ac to dc power supply can output 5a in continous operation and 12a peak current. Careful circuit design has resulted in outstanding load and line regulation, comparable to many commercial power supplies. The schematic and parts list are designed for a power supply. If you are starting to learn electronics variable bench power supply is the first thing you should build to power your projects.
168 810 1067 28 1263 700 542 936 995 1383 276 1316 933 120 71 72 530 731 517 744 1153 91 1174 356 1181 629 421 850 533 1382 217 1146 543 412 523 500 1269 1036 863 596 905 673 954 1342