DIY Variable Lab Bench Power Supply from ATX - How to Make it Cheap

In this video I will show you how I created a Variable Laboratory Power Supply from a computer ATX. Don't throw these PSUs away! These can be very useful for any electrical project. The whole power supply is very cheap, no more than 10$. The main unit of the device is a ZK-4KX Buck-Boost converter module, that is adjustable in 0.5-30 V and 0-4 A range. Additionally you will need some basic components only.
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For detailed description and images see the project on my web page: mtelectronics.tech.blog/2020/...
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[@julio_invest]

the best video of demonstration and how set this module! thanks a lot Dude! hugs from Brazil!

[@toffifee416]

Great video, thanks to you I have a laboratory source, but I would rather put speaker terminals on the front panel. Yes I use google translator.

[@rahulkalra2126]

great video .. thanks .. how to make a rectangular hole on metal is something that i was looking for and this video helped a lot !!!!

[@lorenzfrein2699]

Best video i have seen in a long time.

[@alejandroleon3365]

Great job, very very interesting, thanks a lot

[@tiagocosta9714]

never would've known that ZK-4KX existed if it wasn't for you video, thank you sir

[@enriquegalleguillo1102]

Espectacular video sobre todo la parte final donde calibras los valores exactos de salida de voltaje y corriente. Te felicito .

[@paulogiovanij]

Tx you give me good ideias, greetings from Brasil.

[@MESURIYAPRASATHM]

Good job Definitely u can reach more subscribers

[@user-tt3pb2ry6w]

Hello. Can you help me? Current stabilization does not work properly after calibration. With a setting of 2A, the current is stabilized at 1.8A. What is the problem? How can I reset the installation to factory settings?

[@Alexandre64842]

Thanks for your video. Help me very much.

[@nutty4u2c2002]

Nice Video, very informative. Can the Zk-4KX be reset to factory settings. And if so how is this done.

[@unlockcelular9730]

Could the ends of the source be used in a heating element? to cut duroport? the source is not blocked with a heat resistor?

[@qiuzimorp]

2:19 What is the cut size on the front panel so that the ZK-4KX fits perfectly?

[@regis2424]

Hello, Can i cut off the extra wires ? All wires of same color together as if they are a single wire. And then solder it of the end of each bunch as if it was one wire. I think high currents/amps better. And also can i use a spot welder for battery 18650 with this kit ? Thanks

[@rctechcellassisteccarlospo792]

Muito bom , fiz a minha assim também. Parabéns

[@slavoljubristic7876]

Is it possible to install two LEDs, green and red, to show when charging is in progress and when the battery is charged

[@mizanurrahaman1379]

Really helpful video

[@edylsonn10]

I bought one of these but it has 0.027 A even without connecting anything. Is it a defect? or is it a parameter ?

[@Bianchi77]

Creative video, thanks :)

[@kris54241]

Is there a way to get one that runs at higher amps? My PSU can put out 49amps and the charger I'm using accepts up to 30A

[@milivojeG]

Is that the PSU where "dummy load" on 12V or 5V power rail is not necessary? Cause I haven't see that you set the one? I see it was marked as PFC, which is fine. Thanks

[@danielgeorgiev5023]

hello my friends. can someone tell me what is the power transistor under the heatsink (Q2)?

[@sc7609]

Hello, very informative video and web page. Thanks. Question: I saw in another person's video, he instead of cutting off the extra wires, fused all wires of same color together as if they are a single wire. And then he soldered the end of each bunch as if it was one wire. If I understood it correctly, according to him, it carries high currents/amps better. Is this true? Should one do that? Your module is up to 4 Amps. I was thinking of using a 20Amp module instead. If above is true, bunching of wires will be useful in that case. Thanks for guidance.

[@powerzx]

Yes, more wires can deliver more Amps. Problem with power is not about thick wires but also about electronic parts, PCB design and passive components.

Great videa, thanks :) Has this bench short circuit protection on output? Thanks

[@mtelectronics4242]

Thank you! :) Yes, it can limit the output current too! So if you make a short circuit, it will drop the voltage while limiting the current to the maximum value.

[@choppergirl]

Hey, does this remember all it's functions when it loses power, and also, can you lock the controls so bumping the turning dial won't increase/decrease the output voltage (and damage your equipment). I want to install this on a Radio Transmitter and I don't want to exceed 8.4v DC output.

[@mtelectronics4242]

Hi! Yes it saves the voltage/current values, so it starts with the latest settings after power up. But as far as I know it doesn't have a lock functionality.

[@albertorobles4830]

Can work in short circuit for repair boards?

[@willpiper415]

Thanks o/ very good.

[@ivanpetrov4917]

Great video! Very informative. But you should consider putting some disclaimer, because some new to electronics guy/girl try to recreate this. He/she will be playing around with high voltage. Imagine not knowing how to reassemble the power supply unit after dissassembling it for painting and miss on putting the ground wire to the metal body of the power supply unit. Then that person might be in danger. Congratz on the video anyway.

[@adilislm-th2jy]

ZK-4KX DC DC Buck Boost Converter I can run a 12 volt 2 amp fan with it ?

[@MrLfarah]

Hi. Computer ATX has 12V. How out 28v ?

[@lwizzit]

Is the rocker switch on the high or low voltage side? That is, do I need a 120VAC or 12VDC switch?

[@mtelectronics4242]

It's enough to use a low voltage switch, to sort the green wire with the black.

[@markgilcorido750]

This module can't be used with 30V @full current because it limits @50W only, you can use the full current @12V only.

[@mtelectronics4242]

That's correct. From the other way around, you cannot use 4A @full voltage. You have to limit one or the other when using higher power. "Over Power" functionality will prevent too high power usage, and stops the module if it happens.

[@osmanharmankaya9777]

Değerli üstad, benim zk4kx Modülüm 19v laptop güç adaptörü ile çalışıyor ancak en fazla 7.72 volt çıkış veriyor, bu sorunumu nasıl cozebilirim bana yardımcı olabilir misiniz, teşekkür ederim

[@saintkillah8898]

I made this project so I could bend some acrylic but it keeps cutting off 🥺

[@TheMrMaxx]

Does this Module remember your settings like voltage and current after a power loss?

[@mtelectronics4242]

Yes, it saves those values and starts with the latest settings.

[@horeggg7972]

can you please help, the output volt is stuck at 28v and the volt display ajusdment is more advanced 1v, which is clearly out of sync thank you

[@mtelectronics4242]

It shouldn't stuck in normal case since it doesn't require anything just input power to work. It might be that the rotary encoder is not working properly.

[@regis2424]

Can i use a ATX550W……..WT-4100cc ?

[@postpoquelin]

Very cool! I will try to do the same one. One question: if I want to add a USB port to charge small devices such as a smartphone, I simply need to use the 5V grey wire that you did not use? Thanks a lot

[@mtelectronics4242]

Thanks! No, grey is only a signal to indicate that power source is working fine. Use the red wire instead, or purple (standby) also can be used if you want to charge when psu is off.

[@postpoquelin]

@@mtelectronics4242 I have a new question: is it safe to go above 12V with the converter given that this ATX power supply is designed for 12V?

[@mtelectronics4242]

Yes it is. The output of the PSU is still 12V even when you set lower or higher voltage on the converter. The higher voltage is handled by the converter. I recommend to search for how a buck-boost dc-dc converter works. In case of higher voltage it behaves as a boost converter.

[@postpoquelin]

@@mtelectronics4242 Perfect thanks !

[@postpoquelin]

MT Electronics Thanks again, I think I have got everything to build it. How are called the items you use to cover the holes of the PSU? Thank you so much once again, I hope I’m not bothering you. Your instructions are very clear, but I’m a beginner... Thks!

[@donnyduggan1713]

Hey, nice vid! Couldn't tell from the video: can thr buck-boost module you used set amperage as well as voltage (I was confused because it only has one knob)?

[@mtelectronics4242]

Hi! Thank you! Yes you can set voltage and current values as well on it. You have to navigate in the menu with buttons to set the current, and use the knob to change it.

[@donnyduggan1713]

@@mtelectronics4242 Awesome! Then I'm about to build my own, and using some inspiration from Kralyn3D, I'm going to use a rocker switch and a 5A diode to add a number of direct dc input ports as an alternate potential power source.

[@muhamadhafizibinibrahim2718]

Which line to add USB port?

[@tapanmajhi165]

I want to buy this product but how?

[@HungPham-ki9wu]

I dont get it. The blue "display" part can work itself. Why do you need the psu.

[@jamesjones-yn1sv]

why didn't you put a 3v as well as the 5V and 12V to make it complete

[@giladit77]

Hi, where can I see the schematic? And the list of parts as well. Great job I am also interested in putting together such a power supply. Thank you.

[@mtelectronics4242]

Hi, unfortunately there is no schematic for it, but hopefully you can follow how to connect parts from the video. Used components are also listed at the beginning of the video, or there is some description about at my site (see in description).

[@bongd244]

Good video, I tried this modification with my ATX power supply and it gives me 12V(7A) and 5v(3.5A). Intended for my Cordless 12v drill. But once connected my drill to 12v line, the power supply turn off. After restarting it, tried several time and same thing happen. then, I connect my drill to 5 V line and surprisingly, it run without stopping the power. So, whats wrong with my 12v line. Can you give me an idea how to repair it. Many thanks! Appreciate it much if you could help me.

[@mtelectronics4242]

Some ATX PSUs might need a dummy load on the 5V even when only 12V is used, else a protection will switch off the power supply. It could be the same in your case as well. Try to load the 5V rail with a 10 Ohms or less resistor (5-10W), while using the drill on the 12V rail.

[@bongd244]

@@mtelectronics4242 Many thanks I ll do that! ijform you later.

[@b.vamshigoud6787]

Hi , there.May I know why did you use 3.3ohm load to caliberate the settings

[@mtelectronics4242]

Hi! That's what I found at home that has low resistance with high power rating. Any resistor can be used with higher power rating, the important thing is to calibrate the device under higer load.

[@b.vamshigoud6787]

@@mtelectronics4242 THANK YOU UNDERSTOOD! Can you please give the new link of ZK-4KX Module ,Think they are no more

[@alializadeh8195]

Thanx

[@leandrocesar7590]

Tem vários aspectos a considerar sobre esse vídeo. Primeiramente este conversor chega a 30v com 4 A de saída, achei o cabeamento de saída bem fino asim como o de entrada, portanto exigir a corrente máxima neste caso achei arriscado. Segundo achei tbm o cabeamento fino para os bornes de 5v, eu usaria mais de um cabo para este fim, de resto achei bem legal a ideia, eu usaria as tensões de +3v,+12v e -12v em outros bornes.

[@leandrocesar7590]

@CANAL APOLOGÉTICO cara, eu tenho uma construída desta forma e indico demais, minhas observações são: 1-utilize no projeto uma atx true rms pra garantir uma boa corrente de entrada no buck boost já que segundo o fabricante o buck é capaz de converter de 88 a 96% de potencia na saída comparado a entrada. Então, utilize uma atx capaz de fornececer 12v a 15 amperes max na saida(180w) que convertido na saida do buck pode dar 158W descontado as perdas internas. 2- Utilize pelo menos 4 cabos pretos da saída da atx ate o IN- do buck booster e 4 cabos amarelos na entrada IN+ do conversor assim vc garante uma potencia na entrada do buck sem perdas. 3- para out+ e out- do buck(saida) utilize um cabo grosso de 2mm e com a menor distancia possível até os bornes de saída. 4- aproveite as outras saídas da fonte atx(3,5,-12 e 12v) em outros bornes de saída. assim vc terá uma variedade de tensões independes do buck. lembrando que deve usar no minimo 4 vias de cada cabo se for usar esta opçao

[@leandrocesar7590]

@CANAL APOLOGÉTICO amigo depende da placa mãe e dos periféricos

[@leandrocesar7590]

@CANAL APOLOGÉTICO se montar ela direitinho sim, porem fazer um buck para alimentar uma placa de pc e melhor usar a própria fonte pra isso não?

[@leandrocesar7590]

@CANAL APOLOGÉTICO acho que com 4amperes somente ela só vai ligar notebook, PC de mesa pedida de muita corrente pra ser ligado

[@leandrocesar7590]

@CANAL APOLOGÉTICO então ums 350w mas aconselho vc a olhar a corrente do 12v, se éla der por volta de 15a amperes tá otimo

[@aknulakc1313]

If we use -12 and +12 for two terminal. Do we get 24 v?

[@powerzx]

Yes, but -12V line is very weak in ATX PSUs. Look here 0:36 you can see that -12V has only 0.8A and +12V has 16A.

[@sweetghar3049]

model ps-5141-2d1 wiring diagram

[@cyberspider78910]

By far, Simplest construction....

[@MESURIYAPRASATHM]

Good luck

[@michaelalfonso8145]

Hi, you didn't use a 10w 40 ohm resistor anymore? And no need to connect the brown sense wire to 3.3V?

[@mtelectronics4242]

Hi, no I didn't use them. They might be required by some older PSUs.

[@michaelalfonso8145]

@@mtelectronics4242 how do we check if a resistor is needed?

[@mtelectronics4242]

Try without it, and if it shuts down after some seconds, try with a resistor on 5V or 12V. I don't really know what the brown wire stands for.

[@michaelalfonso8145]

@@mtelectronics4242 thanks!

[@HaggardEffect]

@@mtelectronics4242 I was trying to figure out what the sense wire was and found this on Reddit by 'grabster'. "It is to save money. The 3.3v wire would have to be very fat to carry the high current with out too much voltage drop. Instead, they measure the voltage at the load, and the psu raises its output voltage when there is high current, to maintain 3.3v at the load".

[@taunteratwill1787]

Looks strange with the display on the side. 😉

[@indidip5631]

Buck boost modul price?

[@mtelectronics4242]

No more than 10$, can be cheaper. I bought it on ebay.

[@indidip5631]

@@mtelectronics4242 thank for information. The module has a CC CV functions?

[@mtelectronics4242]

Yes, it has both. Indicates CC on LED.

[@JohnSmith-vz8pc]

Not good practice. you'd better use a 12/13.8V input larger boost/buck on a heatsink.

[@christopher8199]

Hey can you explain a little bit more?

[@Xiaoxiaoxiaomao]

👍🏻

[@nasalimbu3078]

Ups mother board

[@alro7779]

Poor resistor!

[@guillermoseijo2437]

como jugas al oficio mudo, tube que bajar a la mitad la velocidad, y rebobinar Varias veces para entender que es lo que estas haciendo. No se entiende porque el led rojo de encendido, enciende al enchufar a la toma de corriente alterna, deberia encender cuando accionas el interruptor, asi, no tiene sentido. El display es muy bonito, muy lindo, pero: nadie entiende que hace, al parecer, hasta te toma la temperatura...hay que hacer un curso para entender, para que sirve, como se usa y como se ajusta, ya que parece que eso es lo que haces al final del video. La verdad, entendi poco de lo que hicistes, nunca dijistes que amperaje obtenes de salida, tampoco se entiende el porque de los 4 conectores, si al parecer, tenes salida variable de tension con el potenciometro del display. Sinceramente, esto es chino puro, si lo hicistes para fanfarronear, bueno, de lo contrario, o lo haces explicado como para la gente comun, o mejor, no subas mas nada, solo ponelo en estado de watsap, a ver si tus amigos te aplauden...

[@just1lifexx11]

I didn't buy.. to much pressing, setting and stuff. But good video

[@SolangeMassa]

Gratidão 🙏

[@citizengkar7824]

I personally don't believe this is the best solution to achieve an ATX bench power supply. You are asking hobbyists to discard the {potential} majority, of the available current, of the power supply. Alot of PC PSUs are able to deliver more than 10-20A, on some of the voltage rails. Further, these ZK-4KX converters are merely adequate at delivering 3A, over a period of time, let alone 4A! I have tested one of these modules, to charge lithium batteries, & within 3-4 minutes the unit has gone into over temperature mode. Their specs are over-rated. At the very least, it requires active cooling (fan), if operating above 50%, of it's rated current. I would state using good quality potentiometers, to regulate voltage/current, would be a better option, to allow the full optimisation, of the regulated PSU.

[@home_Grown_studio]

Whats the point in making a video if you are not going to explain what it is you are doing.. You are speeding through the project whats the point dude ???

[@mtelectronics4242]

Whats the point writing a comment like this without reading the description?

[@oturanboga6225]