Jun 15, 2019 the ic lm338 by texas instruments, is a versatile ic which can be wired in numerous different ways for obtaining high quality power supply circuit configurations. Variable power supply 030v 20a lm338 electrical note. The 317 is a monolithic integrated circuit with adjustable 3terminal positivevoltage regulator designed to supply more than 1. The following schematics show typical circuit applications for the lm317 lm338 lm350 voltage regulators. Above 15v differential, power dissipation is limited by internal protection circuitry. The meter is a perfect addition to any power supply, battery chargers and other electronic projects where voltage and current must be monitored. This is a combination of two schematics found on the internet. Lm317d lm317, ncv317 voltage regulator adjustable output, positive 1. If you want to make it into a variable bench supply use a pot so that you can easily adjust and also with better the longevity of the variable resistance. Using lm317 or lm338 as adjustable current limiter for atx lab power supply page 1.
I recently build a psu with fixed regulators and also a variable voltage lm338 but in use soon found that a current limiter would be a handy thing, so rather. The other one i am using to create a portable power station for my desk. Please wash your hands and practise social distancing. Here well try to understand how to construct a simplest power supply circuit using the ic lm317. Till now we have seen a lot of power supply circuits, but the main advantage of this power supply circuit is that it can vary the output voltage and output current. The following circuit examples simply depict few of the very interesting useful power supply circuits using this ic. But what if need to vary the power supply voltage, so here we have variable voltage regulator ic lm317.
For a transformer that can supply at least 30 amperes, and voltage secondary coil, should not be less than 18 volts. Home power supply circuit lm338 adjustable power supply circuit. 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. Power dissipation is specified at these values up to 15v inputoutput differential. Aug 07, 2019 sir im refering to this first circuit l. 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. 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. Lm317 lm338 lm350 voltage regulator calculator and circuits. Heres how to build your own adjustable power supply based on lm317. Build a 5 amp portable power supply with an lm338 regulator. To see other pictures of the article variable power supply 030v 20a lm338, you can select them via the navigation menu below.
Power supply schematic and parts list is provided here. Lm338 datasheet adjustable power supply 5a and 10a. Some circuits would be illegal to operate in most countries and others are dangerous to construct and should not be attempted by the inexperienced. Home power supply power supply circuit 10a lm317 adjustable power supply and current booster. Last updated on june 15, 2019 by swagatam 53 comments. I will explain the circuit step by step as we go through our project. Threeterminal 5 a adjustable voltage regulators stmicroelectronics. Have you ever tried to design a variable regulated power supply. To3 lm338 application pin diagram ic lm338 lm338 used as a current regulator lm8lm238 lm338 application note for lm338 lm338 power supply circuit of ic lm338. Mar 21, 2015 if you want to a variable dc voltage power supply circuit during 1. To know more on the basics of this subject, you may also refer regulated power supply. Mar 20, 2015 high power dc regulator 420 volts 20 amps by lm338 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.
The lm317 is an adjustable threeterminal positivevoltage regulator capable of supplying more than 1. Schematic diagram searchable pdf for iphone 6s 6s pluswe will send the. From now it is advisable to proceed with extra caution since we are dealing directly with ac mains and high current. Lcsc electronic components more asian brands, lower prices. Most are designed to convert high voltage ac mains electricity to a suitable low voltage supply for electronics circuits and other devices. Add a 350ma load and the power supply voltage slowly drops down and then out. Variable power supply using lm317 voltage regulator. High power dc regulator 420 volts 20 amps by lm338. The circuit of variable power supply 030v 20a lm338 is built using the lm338 ic regulator 4 pieces arranged in parallel. Here are two simple acdc power supply circuits, one without a filter and one with. Refer to the maximum ratings table for safe operating area. Using lm317 or lm338 as adjustable current limiter for atx lab power supply. 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. The ic lm317 is so versatile that an almost unlimited number of different, small, high grade power supply circuits can be built using it.
An essential part of an acdc power supply circuit is the. As long as one input voltage remains within the common mode range, the comparator will provide a proper output state. The response time specified is for a 100 mv input step with 5. However make sure that all the 2n3055 are mounted over a large common heatsink, using a generous amount of heatsink compound paste but without mica isolators. Note that all these links are external and we cannot provide support on the circuits or offer any guarantees to their accuracy. The complete circuit of this variable power supply is shown below, follow the schematics and solder you components accordingly. It is exceptionally easy to use and requires only two external resistors to set the output voltage. With the aid of a small bit of additional circuitry. Lm338 adjustable power supply circuit electronics projects circuits. It easy circuit and nice circuit, because use ic lm338 and ic 741.
The nominal output voltage is selected by means of a resistive divider. Power supply and power control circuit diagrams circuit. High current dc regulated power supply circuit with lm317. I find this circuit, for an electronic friend, according demands of those who want the the power supply, good quality, excellent performance. Each one ic lm338 can provide a variable output voltage of 030v and have a current capacity of up to 5a, so that. That is why power supplies and voltage stabilizers are one of the most popular topics, enjoying uninterrupted interest. Power supplies, mpumcubased systems, industrial controls, computer systems and many other product applications are requiring power supervisory functions which monitor voltages to ensure proper system operation. Lm8, lm338 snvs771c may 1998revised december 2016 lm8 and lm338 5amp adjustable regulators 1. Hi, i built a standard power supply from the datasheet for a lm338 regulator. Lm8 and lm338 5amp adjustable regulators datasheet rev. Build an adjustable 230 volt power supply with the lm317. 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.
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. It is easy to build and uses lm338 and 741 integrated circuits. It will come in handy to power up many electronic circuits when you. The meter uses pic16f876a microcontroller with 16x2 backlighted lcd. Sep 28, 2019 high power dc regulator 420 volts 20 amps by lm338. Use very good heatsinks for lm338 and bd140 transistor.
High current adjustable voltage regulator circuit, 030v 20a. Lm317 lm338 lm350 voltage regulator calculator and. Careful circuit design has resulted in outstanding load and line regulation, comparable to many commercial power supplies. The resource is currently listed in in a single category. Various misfortunes drive me in a state where i need to construct a lm338 voltage regulator. The circuit also incorporates an electronic output current limiter that effectively controls the output current from a few milliamperes 2 ma to the maximum output of three amperes that the circuit can deliver. They offer the designer several important advantages over linear seriespass regulators. The fixed voltage regulator is used to offer fixed voltage at the output terminal and does not depend upon the input voltage supplied. Draw the respective output voltage waveforms of these two power supply circuits v. Lm338 datasheet adjustable power supply 5a and 10a elec. It will come in handy to power up many electronic circuits when you are assembling or building any electronic devices. Lm338 circuit 1,5v32v 3a s you know, every electronic circuit needs power.
It seems that most of the schematics that i have found use 2425v input. Lm338 ic pinouts datasheet, cross reference, circuit and application notes in pdf format. How to make a simple variable power supply using ic lm338. Few lm317 voltage regulator circuits that has a lot of. Power supply and power control circuit diagrams circuit schematics. An essential part of an acdc power supply circuit is the filter, used to separate the residual ac called the ripple voltage from the dc voltage prior to output. Positive excursions of input voltage may exceed the power supply level.
This ac to dc power supply can output 5a in continous operation and 12a peak current. Almost all electronic devices used in electronic circuits need a dc source of power to operate. Image the circuit of variable power supply 030v 20a lm338 above is one of the images in the article variable power supply 030v 20a lm338, hopefully with a bigger image display can be seen more clearly. Now that our display is ready let us start with the other circuits. Using lm317 or lm338 as adjustable current limiter for atx. I am building two of these, with one slotting into my main power station, the powerstation2. The pot can be preset if you application is for a constant voltage supply for a specific circuit.
Jan 22, 2016 variable power supply circuit from fixed voltage regulator. Hello, i am getting ready to start a 03032v regulated psu using a single lm338t. This dual power supply circuit can be used for general purpose applications due to their clean and reliable outputs that is suitable for versatile benchtop testing and other bench requirements. Welcome to a new voltlog, today we are building a very simple constant current regulator based on the lm338 linear regulator. Here are two simple acdc power supply circuits, one without a. Here is the lm338 adjustable dc power supply circuit, 1. This kind of dc power supplies uses a pcb so you can use two case. Lm338 spice model datasheet, cross reference, circuit and application notes in pdf format. This article describes you how to design a variable power supply circuit. I also attached these schematics solar battery charger and variable dc power supply. The presented power supply is an application of the popular lm338 regulator ic, which housed practically all elements of the high voltage regulator lm338.
Jun 19, 2018 building 024v 3a variable power supply circuit. If you want variable regulated power supply high current more than 10a up. The video shows how to make a simple 030v variable power supply circuit using ic lm339, 120 ohm 14 watt resistor and a 10k pot. Dec 11, 2017 we have 78xx 7805, 7806, 7812 etc series voltage regulators for positive power supply and 79xx for negative power supply. 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. Careful circuit design has resulted in outstanding load and line regulation comparable to many commercial power supplies the lm8 family is supplied in a. Batteries are often shown on a schematic diagram as the source of dc voltage but usually the actual dc voltage source is a power supply. This voltage regulator is exceptionally easy to use and requires only two external resistors to set the output voltage. Jan 10, 2018 thus this simple tweak using a few 2n3055 transistor transforms a ordinary lm317 variable regulated power supply into an awesome high current lm317 regulated variable power supply unit. If you have used lm317 or lm350 they are similar, so easy to use with a few components. Lm338 adjustable power supply circuit electronics projects. It began as a variable power supply based on an lm338 5a voltage regulator and external power adapter. This is a regulated and adjustable power supply which can deliver up to 20a and adjustable voltage between.
Lm338 adjustable power supply 5a power supply circuit. 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. This is a high quality power supply with a continuously variable stabilised output adjustable at any value between 0 and 30vdc. Lm338 adjustable power supply 5a and 10a elec circuit. Therefore, the input voltage to the lm317 lm338 lm350 regulator will. 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 488 times. Recent listings manufacturer directory get instant insight. High power supply regulater 030v 20a by lm338 circuit.
Pak packages intended for use as positive adjustable voltage regulators. The main category is power supply projects that is about power supply projects and modifications for ham radio. The configurations can be introduced for different applications for upgrading an existing unit with features that would virtually make it indestructible. This circuit is used to convert the dc supply into high frequency, high current ac, which by various means. Looking at the proposed high current lm317 regulator circuit design we can see how the basic lm317 variable power supply design which is normally rated to deliver just 1 amp current is cleverly upgraded to a high current version using a few 2n 3055 transistors. Voltage regulators find their applications in computers, alternators, power generator plants where the circuit is used to control the output of the plant. Check for continuity using a multimeter every time before you power you circuit. You can expect performance of both the line and load regulation using the lm317 lm338 lm350 adjustable voltage regulators over that of standard fixed voltage regulator. I have been browsingsearching for a good circuit with this chip.
Lm338 adjustable power supply circuit electronic circuit. If the current limiter is set to 1a, under short circuit conditions, i dont want power interruption. 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. The power supply has a 120 to 28 vac transformer feeding a fullwave. The most important part of this circuit is the 317 variable voltage regulator. For transformer that can supply at least 30 amperes, and voltage secondary coil, should not be less than 18 volt. Volt ampere meter measures voltage of 070v or 0500v with 100mv resolution and current consumption 010a or more with 10ma resolution. 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. This is a regulated and adjustable power supply which can deliver up to 20a and adjustable voltage between 4 and 30v. The dropout voltage of the ic regulator is about 1. Its a circuit of adjustable 10a regulator, with the ic lm338. Motorola offers a wide range of power supervisory circuits that fulfill these needs in a cost effective and efficient manner. Lm317 slvs044x september 1997revised september 2016 lm317 3terminal adjustable regulator 1 1 features 1 output voltage range adjustable from 1.
How to use lm317 for making a variable power supply circuit. Ic lm338 application circuits homemade circuit projects. In this tutorial we will show you how to get the variable regulated voltage from the lm317 ic. This ic is normally available in to220 package and. For this weeks project i have built a 5 amp variable voltage regulator using an lm338 serial regulator. The lm217, lm317 are monolithic integrated circuits in to220, to220fp and d. Here is the circuit producing variable voltage power supply designed using fixed voltage regulators.
This variable voltage is connected to pin a0 using. The circuit of variable power supply 030v 20a lm338. May 11, 20 the most important part of this circuit is the 317 variable voltage regulator. If you want to a lm338 variable dc voltage power supply circuit during 1. The switching power supply continues to increase in popularity and is one of the fastest growing markets in the world of power conversion.
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