Build Your Own Variable Lab Bench Power Supply

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Introduction: Build Your Own Variable Lab Bench Power Supply

About: Awesome Electronics Tutorials, Projects and How To´s

In this project I will show you how I combined a LTC3780, which is a powerful 130W Step Up/Step Down converter, with a 12V 5A power supply to create an adjustable lab bench power supply (0.8V-29.4V || 0.3A-6A). The performance is quite good in comparison with other models which cost around the same. Let's get started !

Step 1: Watch the Video !

The video gives you all the information you need to build this correctly. But I will also present you a parts list and more pictures for convenience.

Step 2: Order Your Parts !

Here is the parts list with example sellers (affiliate links):

Ebay:

1x LTC 3780: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x 12V 5A Power Supply: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x AC Input: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x AC Switch: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x Voltage/Current Display: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

2x Binding post: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x 200kΩ Potentiometer: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

1x 500kΩ Potentiometer: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

2x Knobs: http://rover.ebay.com/rover/1/711-53200-19255-0/1?...

Aliexpress:

1x LTC 3780: https://s.click.aliexpress.com/e/_dUULcjH

1x 12V 5A Power Supply: https://s.click.aliexpress.com/e/_d6OKO63

1x AC Input: https://s.click.aliexpress.com/e/_d6rs11H

1x AC Switch: https://s.click.aliexpress.com/e/_d8ahMCn

1x Voltage/Current Display: https://s.click.aliexpress.com/e/_dTLhigJ

2x Binding post: https://s.click.aliexpress.com/e/_dTyymFV

1x 200kΩ Potentiometer: https://s.click.aliexpress.com/e/_d6mRdPZ

1x 500kΩ Potentiometer: https://s.click.aliexpress.com/e/_d6mRdPZ

Amazon.de:

1x LTC 3780: -

1x 12V 5A Power Supply: http://amzn.to/1FIc4vK

1x AC Input: http://amzn.to/1FIc7b5

1x AC Switch: http://amzn.to/1FIceDs

1x Voltage/Current Display: http://amzn.to/1AwUnt8

2x Binding post: http://amzn.to/1ENKLzo

1x 200kΩ Potentiometer: http://amzn.to/1ENKQmP

1x 500kΩ Potentiometer: http://amzn.to/1AwUEfD

2x Knobs: http://amzn.to/1FIcuCC

Amazon.co.uk:

1x LTC 3780: -

1x 12V 5A Power Supply: http://amzn.to/1FId7fh

1x AC Input: http://amzn.to/1R1lRl9

1x AC Switch: http://amzn.to/1AwWsoT

1x Voltage/Current Display: http://amzn.to/1AwWFsa

2x Binding post: http://amzn.to/1ENM3uh

1x 200kΩ Potentiometer: http://amzn.to/1FIdAyb

1x 500kΩ Potentiometer: http://amzn.to/1FIdBSx

2x Knobs: http://amzn.to/1AwXvoY

Step 3: Build It !

Here are some picture which should hopefully help you to build your own supply. And be careful when working with mains voltage !

Step 4: Success !

You did it! Now you have successfully built your own variable lab bench power supply!


Feel free to check out my Youtube channel for more awesome projects:

http://www.youtube.com/user/greatscottlab

You can also follow me on Facebook, Twitter and Google+ for news about upcoming projects and behind the scenes information:

https://twitter.com/GreatScottLab

https://www.facebook.com/greatscottlab

24 People Made This Project!

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226 Comments

0
OsamaZ7
OsamaZ7

Question 3 years ago on Step 3

Can you please share the circuit diagram

0
SteveSi
SteveSi

Reply 2 years ago

The diagram is wrong. You should not connect the thin black wire going into the meter. Inside the meter, the thin black wire connects to one side of the internal shunt. This causes the 0V of the input to be connected to the 0V of the output. This puts the internal shunt of the current meter in parallel with the internal current shunt\sensor in the DC-DC board. It means the current reading on the meter is wrong and also you cannot adjust the current cut-off pot.
See the instructions for the meter. You ONLY connect the thin black wire if you are powering from an independent power supply which has an *isolated ground* like a battery (not a common ground). https://www.banggood.com/custlink/GGmGegbp95

0
dush71816
dush71816

Reply 11 months ago

I think the diagram is for non shunted power meter, there are 2 versions available, 1 is shunted and can meqsure 10A max and others are beyond that ampere range and do not have shunt. To provide load to such meter the black wire should be connected. Correct me if I am wrong.

0
dush71816
dush71816

11 months ago on Step 1

Should have included wiring diagram. I am having confusion about connecting 3 thin wires from power meter. My meter is non shunted one as per supplier and range is 0 to 100 amp. I think the shunt is for a dummy load and bears 10A max. But how 3 wires should be connected with posts is confusing.

0
TurkelA
TurkelA

Question 1 year ago

Hi Scott, I am big Fan of your youtube channel and instructions :)
I would like a bit modify current setup to use with my "3A 12V toroidal transformer" and "LM317 Adjustable Regulated Rectifier Filter". then connect LM317 directoly to LTC3780.
Will this setup work OK? The purpose is to build Liniar Power Supply rather than switching one.

Grate Thanks,
Turkel.

0
nickr20215
nickr20215

Answer 1 year ago

yes as long as it's not over 12v

0
MathieuC35
MathieuC35

1 year ago

Hello. I'm a little confused. My display does not look exactly like the one in the pictures. The power wires are thin and the group of 3 wires are thicker. That group has black, red and green but no yellow. It doesn't look like they are identified on the board either. See picture. Can I make it work or should I just order a new one that looks like the one in the pictures ?

Thanks !

IMG_20200517_155309.jpg
0
nickr20215
nickr20215

Reply 1 year ago

Check the datasheet of your vesion it should have a wiring scheme

0
InstructaPudah
InstructaPudah

Question 3 years ago

Would it be possible to control the LTC3780 digitally, maybe with an Arduino and a DAC or digital potentiometer(s) with rotary encoder for voltage control instead of the pot?

0
Tricep Terry
Tricep Terry

Answer 1 year ago

i'm also investigating this, for now going for a kinda weird solution which is to mount the potentiometer near a servo motor and use gears to turn it, its gonna be ugly for sure, yet practical and simple.

0
Zemon_Compute
Zemon_Compute

Question 2 years ago

So with mine, I can adjust the Voltage fine but the current I cannot adjust at all. it only automatically draws Current. anyone know what could have caused that?

0
Swami7233
Swami7233

Answer 1 year ago

Did you able to adjust current after removing the small black wire?

0
SteveSi
SteveSi

Answer 2 years ago

The meter is wired up wrong. Do NOT connect the thin black wire going into the meter.

0
Zemon_Compute
Zemon_Compute

Reply 2 years ago

So i should disconnect this one from everything?

unknown.png
0
SteveSi
SteveSi

Reply 2 years ago

Yes

0
jayurban015
jayurban015

1 year ago

Greetings! Could you supply a link or a source for that terrific Project Box you used? I cannot find anything like that on eBay.

0
saisriram
saisriram

Question 1 year ago

Please upload the circuit diagram

0
CarlosC445
CarlosC445

2 years ago

Ótima iniciativa com grande criatividade trazendo uma opção de baixo custo e grande importância em projetos de educação tecnológica, essa adaptação de módulos prontos de power suply para montar uma fonte uma power suply de laboratório com custo reduzido ajuda em muito. Obrigado e um forte abraço. Prof Carlos Otávio Cardoso. NOTA 10!

0
MohammadA590
MohammadA590

Question 2 years ago

i want ask
about ampermeter screen,when i set amper ,are the info shown in screen, show my set or the exactily amper when i connect the load ?