DIY variable bench power supply (For actually 17$)

[@kajyakuzonik9130]

It's always nice to see various case constructions. However, there are a couple of things I would've added to increase the safety and those are atleast a) A fuse on the primary side. This could be e.g. one of those power-switch + mains cable + fuse-holder all-in-one thingies. b) Using proper screws to mount all the three PCBs firmly to the case. Hot glue can come loose and the loose PCBs could then potentially short-circuit something or make secondary side wiring become live.

[@sasiskas]

There is already a fuse on the 24v power supply, so you don't have to add one more. You are right about the hot glue, hopefully it will last. Personally I don't mind because I never move my bench power supply, so there is no chance of something getting loose.

[@robertcartier5088]

Nice case! But as the fan pushes hot air out, where is the cooler air coming in from? Nowhere... that's why it needs air holes. ;-) A few hole in the bottom should do it. They should be near the front so the airflow travels the length of the case.

[@sasiskas]

Thnx for the comment. The fan pushes air in, not out. When it pushes air in, it lifts the lid for a couple of mm, which acts as an exhaust. It was just a personal preference because I don't like the looks of the vent holes.

[@robertcartier5088]

@@sasiskas Good answer! ;-)

[@sasiskas]

@@robertcartier5088 thank you for your comment and feedback. Cheers

[@robertcartier5088]

The double pole switch is not required. Your safety concerns, in this particular instance, are exaggerated. The neutral connection is not Live, and with a 3 prong wire, the polarity cannot be reversed. Therefore, switching both the Live And Neutral is completely irrelevant. The only way that switching both wires is safer is if you are using a 2 conductor plug. It is done to prevent the reversal of the plug connecting the Live to the Neutral input, which cannot happen here.

[@sasiskas]

Thank you for your comment. Unlike the UK,US,CA and maybe a few more counties that use 3 prong plugs, the rest of the world (e.g. most European countries) use 2 prong plugs (e.g. Schuko plugs) which are not polarized. As a result, you can not know which will be the hot wire, since the appliance can be plugged in either way. Exactly for this reason a two pole switch is very important, especially in this case, since it is a DIY project and it is almost certain that someone will tinker with it while it is plugged in, thinking that it is turned off. One more thing is that I don't know the level of knowledge of the person trying to replicate this project, so being super safe is certainly not bad.

[@robertcartier5088]

@@sasiskas So, yet again, in compensating for the stupidity of the masses, we will recommend that all others spend more money than they have to for an unnecessary safety feature... I say let Natural Selection become a thing, again! ;-] Thanks for the replies, cheers!

[@squareroot99999999]

Very nice.. I might even try that.. The only change I would make would be to get rid of the terminal blocks on the buck converters and power supply and solder the wires directly to the boards. Those terminal blocks always seem to give me problems.

[@sasiskas]

squareroot99999999 so far no problems for me, but you can remove them if you like just to be sure. I wish you to have fun with this project! 😁

[@karthikjsv2921]

Can the ground terminal be connected to ANY metal part inside the case? and I'm not using a switch mode supply like your's, but using a transformer and a bridge rectifier and feeding the output DC to the 12A buck converter. I'm just using a two terminal AC adapter for supplying the transformer(without ground terminal). Is it safe without the ground? I heard that when we use a transformer, it takes care of all the protection.. but still many people connected the ground wire to some metal part of inside the case.

[@sasiskas]

You should connect the ground terminal to anything that you want to protect in case of leaking AC current. Usually it is connected to the box (if metal box) in order to protect the user when touching the box. If in your country your wall outlet doesn't have ground pin, then there is no point of grounding anything. If your wall outlet has a ground pin then I highly recommend that you ground your power supply. If you have a metal box I suggest that you connect the ground to the box. Doesn't matter if you use transformer or switching power supply... the transformer isolates the primary from the secondary, but it doesn't protect you in case of leaking AC current from the primary.

[@karthikjsv2921]

@@sasiskas Thanks for your reply! But i'm not using a metal box, I just want to use a box made out of acrylic. In this case how can I provide the ground? (Or should i?) and there are adapters with 3 pin(which includes ground) and 2 pin as well. Since i was not familiar with grounding and all that stuff, i just had to stick with the 2 terminal one.

[@sasiskas]

Karthik Jsv sorry for the late reply, but I didn't receive any notification. Just connect the earth wire to the metal core of your transformer.

[@sasiskas]

Karthik Jsv as an example, take a look in this video the Earth wire (it's the green wire) kzbin.info/www/bejne/bprXhX5-atmdadU

[@karthikjsv2921]

@@sasiskas Thanks for the info :D

[@cheat_steve10]

Finaly, a video about a Power Supply WHITOUT enoying music and with a propper ground

[@anunaccountablescience6464]

Annoying

[@BobMellor1954]

Nice build

[@sasiskas]

thank you for your kind words

[@RigoHoward]

@sasiskas its been a while, first of all i want to thank you again because of you i made my regulable PSU following this video and after all the issues and questions i posted here i got i working well. Currently i experienced a problem related to the voltage knob, when i turn it slightly to the right or the left the ammeter shows the voltsge goes from 3v to 18v (when raising) or even when going down from 12v it raises to 19v and so on... At first i thought it was the ammeter doing bad readings, but i hook up the multimeter and its reading the same :s So do you think this is a fault of the 10k pot used on the voltage line? (my wiring its exactly as was shown on your video and never had this issue before)

[@sasiskas]

hello, thanks for your feedback. It looks like a problem with your pot, or the 12A buck converter. I suggest testing the cheapest first. Try replacing the pot if that doesn't fix your problem, then It is probably an issue with your buck converter. It's more likely the pot.

[@RigoHoward]

@@sasiskas oooh thank you so much for answering!!, yes i already ask 2 pots to try. Well the 12A buck converter would be the next part to check if the issue remains then. Thank you again and keep it up!

[@RigoHoward]

Luckily it was only the pot the cause of my issue, so now after i change it, i can move the knob with confidence. Thank you again @sasiskas :)

[@justinlacapria2898]

You earned my sub at : Safety shoes ✅ Gloves ✅ 😄👍

[@sasiskas]

😁

[@MichaelAMalone]

Hi, neat build, just wondering how the fan sucks air out of the case when there are no vents for air to enter? Or does the top have enough gaps?

[@sasiskas]

Nice question. I didn't want to to make any holes on the case, because I thinking that they look bad. So I came with the following idea, instead of blowing air out of the case, the fan is blowing air into the case. The lid has hinges, so when the fan blows air in, the lid is slightly lifted and works as an exhaust. 17:03 it is not clearly visible, but you can get an idea...

[@MichaelAMalone]

@@sasiskas cool idea, does it work well? Noise level, floppy top etc.?

[@sasiskas]

@@MichaelAMalone there is no performance issue, because the switching power supply doesn't get hot anyway. The noise is low and can be adjusted by adjusting the fan speed (by adjusting the voltage). That's why I set the fan voltage to 8V instead of 12V. Note that the noise that you can hear after 17:10 is generated by the 2 fans that I use as a load and it is not the sound of the fan in the case. The lid itself is not floppy, it is just very easy to open because of the hinges and because there is no locking or latching mechanism. But that was my intention anyway... The construction of the cooling system is a personal preference, you can always use a more classic approach with vent holes.

[@ichalssy]

Hi Sasiskas, nice video, 👍 Can you tell what is your glue gun type, it seems that the glue not drip when you put it on the table 😁

[@sasiskas]

I bought it 17 years ago from Lidl. I don't think you can find it any more :( model phkp 500

[@TxRiverElf]

Bravo! That is a great looking power supply and I like the hinged top... easy access for cleaning and further tinkering. I would probably go with a better fan though! LOL

[@sasiskas]

thank you for your kind words. I used the only spare fan that I could find...if you can use a better fan, it is a good idea to do so.

[@RiderRc100]

Very nice..Thank you.

[@badrinath6059]

Excellent project,please add block diagram of connections,it willbe more usefull to DIY's..

[@sasiskas]

5:22

[@almahdimajeed6591]

Good & Nice job but your fan need some holes in the box to suck air..continue...Thanks from Algeria

[@sasiskas]

Thank you for your comment. During operation the fan sucks air from the back of the box, then the air flow lifts the lid, which works as an exhaust. I wanted to have a clean look without holes, that's why I did it like that .

[@Bernycoty]

beau projet, .je ne comprend pas d'avoir une extraction de l'air alors qu'il n'y a pas d'entrée d'air?

[@sasiskas]

le ventilateur fournit de l'air à l'intérieur du boîtier. L'air soulève légèrement le couvercle, et cela fonctionne comme un échappement

[@smartech-assistenciatecnic4233]

I have found a 30A dcdc converter with a 12v fan input,can i use that to Power te voltimeter/Ammemeter instead of the 3A Buck?

[@sasiskas]

yes but it's an overkill...

[@smartech-assistenciatecnic4233]

@@sasiskas I gonna see the especifications,i'm pretty sure that the current in 12v output must be 1-2A

[@smartech-assistenciatecnic4233]

And i work with cellphones and computers,só it's good to have a powerful Power supply

[@sasiskas]

A power supply is always useful! 👍

[@umavasireddy]

Nice video. May be some vent holes to the enclosure.

[@sasiskas]

Uma Vasireddy thank you for your comment. I thought about the vent holes, but they are really not necessary, under operation the fan lifts the lid slightly (approximately 1-2 millimeters) which works as an exhaust. When the power supply is turned off, the lid is completely closed, preventing dust from entering inside. It is a personal preference, if someone likes to make a few vent holes, it is an easy mod.

[@andytipping70]

@@sasiskas with holes at the front, the air is directed over the heatsinks, your method , the air escapes from the path of least resistance

[@isaacrivera8810]

the question i have is... Can i make a short circuit and still work? I'd want it for electronic repair but need NO short circuit protection in order to find what component is short circuited. Thanks for the video!

[@sasiskas]

Why don't you use the continuity mode of a multimeter for this job? after all, this is what it is made for :-)

[@Marko_Djuricic]

@@sasiskas What kind of question is that? In motherboard repairs it's easier to inject voltage on closed mosfets on shorted curcuits to find the component that gets hot and you have your problem solved. You'll never find a short with diode mode unless you want to unsolder the whole motherboard and check everything.. Why do we need power supplies? Not just for spinning fans at high speed and charging batteries for sure..

[@sasiskas]

@@Marko_DjuricicThank you for clearing it out. I understand what you mean. I didn't know that when the original question was asked, because I'm not into professional repair of electronics. Unfortunately I can't answer because I have borrowed this power supply to a friend. I will test it as soon as I get it back

[@ImranKhan-dd4vs]

very nice video

[@ImranKhan-dd4vs]

super

[@rudolfgeiling9209]

why must you adjust the buck converter to 8 volt

[@sasiskas]

Rudolf Geiling Thank you for your message. It is not a rule to adjust it to 8v, you have to adjust it according to your fan voltage. In my case I used a 12V fan, but the airflow that I was getting at 8V was enough, at 12v the airflow was unnecessary too much and too lound. Of course this will also power your volt/ammeter, if I remember correctly, any voltage between 2V and 12V is safe for it. I hope I helped you

[@egorgozdak9767]

Скажите пожалуйста, а есть схема подключения всех элементов? Или можете нарисовать и по Вайберу мне отправить? Большое спасибо!

[@sasiskas]

05:21

[@robuk360]

Do you know what size in mm the mounting holes are for all the boards? I'm wanting to get some adhesive stands for them. I purchased all the same components as you.

[@sasiskas]

I will check tomorrow and let you know.

[@robuk360]

@@sasiskas Hi, did you get time to have look for the mounting hole sizes?

[@sasiskas]

@@robuk360 sorry for the delay. It is 3mm for both of the buck converters and 4mm for the 24v psu.

[@robuk360]

@@sasiskas That's great, thank you very much :)

[@cri8tor]

Was that safety glue? Another great video and another project to add to all the other ones that are waiting for me to finish. Cheers

[@sasiskas]

Thanks I appreciate it. I just used a simple hot glue, nothing special.

[@cri8tor]

Just kidding about the safety glue...lol :) Hot glue guns have made so many projects a lot easier. Please consider making improvements and some update videos on your power supply and soldering station. Cheers

[@sasiskas]

@@cri8tor haha I get the joke now 😋 I'm planning to make a couple new videos... probably during the summer...

[@tiger97abd]

You are amazing

[@smartech-assistenciatecnic4233]

Nice,i gonna build one

[@JC-XL]

[0:38] +1 for the safety shoes !

[@malupitpoh]

You forgot a safety goggles.. :) nice project

[@shubhamshukla167]

nice👌 so fine design

[@SteveOfTheMountains]

Can I use this to convert 36v dc to 12v dc ? or does it require a 110v AC source?

[@sasiskas]

Steve Squaw for that purpose you just need the 12A Buck converter from the list in the video description. Of course, if you do a tiny modification on my project, you can make it work for both 240v(110v for N.A.) ac or 36v Dc.

[@ΘΩΜΑΣΚΑΡΑΙΣΚΟΣ-θ5λ]

Question?can you use it for charge a 12-24 v battery?

[@sasiskas]

unfortunately I don't own any 12 or 24v batteries, so I can not tell you for sure. But I don't see any reason why it wouldn't work.

[@ΘΩΜΑΣΚΑΡΑΙΣΚΟΣ-θ5λ]

thank you very much!

[@vipstudypower4802]

Sir I want to make a mobile repairing power supply so discuss about it and it's matterial and fully secure ok thanks. I will wait for your response.

[@tbiowa9977]

Question? Your power supply is rated at 4amp-6amp and your buck converter is rated at 12 amp. What is the maxium amps you can safely pull? I'm guessing 12amps.

[@sasiskas]

As I mention in the video, I don't have a dummy load to accurately test it. These things are made in China, so I wouldn't count on what the seller says. Theoretically, you can output as much power as the power supply can handle, which is 100w (V*A =W). Theoretically you can achieve output 12A with maximum 8V, but I can not tell for sure unless I test it with a dummy load.

[@sasiskas]

just watched a video where someone tested this power supply and achieved 5.3A 24V = 127W, so you might be able to output 12A at 10V

[@tbiowa9977]

Thanks so much!!

[@ejamaulana7380]

Hey can you please share schematic because i don't know? Overall you video very good

[@sasiskas]

the schematic is very basic. you can see it on the video. 5:22

[@ejamaulana7380]

sasiskas ok thanks

[@areza2555]

Hi mate Why 2 buck converter needed?

[@sasiskas]

the big buck converter is used for the variable output of the power supply. the small buck converter is used in order to power the volt-amperes meter and the fan

[@areza2555]

@@sasiskas Thanks buddy. These parts from eBay in England cost 3-4 times more expensive than yours. So I may go only for power supply and converter. God bless you

[@sasiskas]

@@areza2555 you are welcome. You can try AliExpress, I have stopped using eBay a long time ago. The delivery time is the same but the prices are way lower.

[@areza2555]

@@sasiskas Thanks buddy for help, I will try. God bless you 🙏❤

[@areza2555]

@@sasiskas Hello again I already ordered all parts from aliexpress and waiting to arrive. I believe I can use it as a charger, just one question what voltage and current do i need for example for a 5v 1800ma battery? 🙏

[@46bovine]

You do have safety gloves. Har, har, har.

[@jakubmuchowski9832]

Why 2 pole switch is more safe than single pole?

[@sasiskas]

Because in many countries the plug can be plugged in any orientation to the wall outlet. So you never know which is the live and the neutral. That's why you need a two pole switch, in order to disconnect both live and neutral and be safe.

[@jakubmuchowski9832]

@@sasiskas i see. Thanks for explaining

[@RigoHoward]

Hello friend i finally get all the parts to build the power supply but i ran into some trouble :S I double check the schematic and all the connections are ok, but i only can get from 1.1v up to 9.5v

[@sasiskas]

RigoHoward 1. Try increasing the amps 2. make sure that you have connected the wirewound potentiometers correctly. 3. if nothing else works, try using the (little blue) trim pots that came with the 12A buck converter.

[@RigoHoward]

sasiskas i actually remove the two blue trimpots and wired the two wirewound potentiometers, the amp wirewound seems to be doing nothing :s Maybe my buck converter is faulty?, i check the continuity and it gets the 24v input properly at least :o

[@RigoHoward]

sasiskas i check your video again and i found that the voltage wirewound potentiometer wasnt in the proper way. so now i can move from 1.1 up to 23.9v But the amp wirewound potentiometer doesnt do anything on the screen for me :s Can you please show me your wiring for the amp potentiometer?

[@sasiskas]

RigoHoward go to 10:43 to see the amp potentiometer

[@RigoHoward]

sasiskas i check the wiring for the amp porentiometer ans its the same. Without load the ameter should show 0amps right?, i connected a pc fan and when i raise the voltage with the pot, ameter shows values but if i turn the amp pot nothing changes on screen but i can see the cpu fan spins faster or slower

[@RigoHoward]

Hey can you please share the dimensions of your acrylic box ? :) i bought everything from aliexpress but i would probably get an empty plastic box because im to lazy to build one :p

[@sasiskas]

RigoHoward Thank you for your comment. I am sorry but I am away from home and I will be back in a couple of weeks.I will measure the box as soon as I return back.

[@sasiskas]

12*19*8 cm

[@RigoHoward]

sasiskas thank you my friend, i still waiting some of the parts to build this

[@sasiskas]

RigoHoward you are welcome. Yes I know, the hardest thing is to wait for the components to arrive from China 😂

[@sasiskas]

I have added a couple of links, of suggested boxes in the video description, in case someone else likes to buy a box as well. ;)

[@hyperhektor7733]

for the Plastic, it could be processed faster and cleaner when you bend it kzbin.info?search_query=acrylic+bending+machine+diy (it says acrylic but works with any common thermoplastic (ABS, PE, PP, PolyStyrol, Polycarbonate)

[@sasiskas]

thank you for the idea. I might try that on future projects

[@robuk360]

What wire gauge did you use and fan size?

[@sasiskas]

24AWG and 50mm fan

[@robuk360]

Thanks for the reply :)

[@robuk360]

It looks much thicker than 24AWG, I have 18AWG, hope it's not to thick.

[@sasiskas]

@@robuk360 if you talking about the blue wires ( for the AC), it is single core 1mm wire. For the fan and potentiometers (DC wires) I used approximately 22-24AWG (doesn't really matter).If you use 18awg for the DC wires, you are absolutely fine.

[@robuk360]

@@sasiskas do you think 18awg will be ok for the AC also? If not I only have 2.5mm single core wire.

[@markc98761]

Please never wear gloves when using rotating machinary anyone, only with hand tools, if it catches it will not let go and damage will be done

[@sasiskas]

Thank you for your comment. This subject is disputable...l agree with you, but up to a certain point. My opinion is that you shouldn't use loose gloves when operating rotating machinery, and never use gloves when operating machinery that are stationary, or very heavy. Small tools like a dremel, or a small angle grinder are safer with well fitted gloves.

[@robertcartier5088]

Swapping the switch for a 2-pole is not necessary. There is no real justification for the extra cost. Your AC cable is polarized, and cannot be connected the wrong way. So interrupting the Live wire is all you need. Open up ANY commercial equipment and you will notice that none of them have a 2-pole switch for On-Off. That's because there is no reason for it. Other than that, I enjoyed the video. Cool looking build!

[@sasiskas]

Thank you for your comment. Many countries (e.g. most European countries) don't have polarized plugs and as a result, you can not know which will be the hot wire. This is very important, especially in this case, since it is a DIY project and it is almost certain that someone will tinker with it while it is plugged in, thinking that it is turned off.

[@victorimanuelambennu3096]

you are good

[@syedazammir8144]

Not show components list and wiring dia frame.

[@Qubnix]

Can I use 12V 6A power supply?

[@sasiskas]

Qubnix yes, the only difference is that you will be able to output up to 12v and not 24v

[@Qubnix]

Ok, I have one more question, can I use two 24V 3A power supplies connected in parallel to get 24V 6A power output??

[@sasiskas]

Qubnix theoretically you can, but I can not tell you what will happen in reality. I have never tried it.

[@Qubnix]

Ok, and last question, why you do not connected the digital volt/amper meter directly to the power supply output? It can be powered by 3-30V.

[@sasiskas]

Qubnix I don't remember the maximum voltage it can support. Anyway you need a lower voltage for your fan, so better play safe an use that low voltage to power your volt/ammeter

[@lucasthomazon]

what is the dimension of your box??

[@sasiskas]

12*19*8 cm

[@sasiskas]

links for suggested boxes can be found on the video description

[@junaid786bd]

Dear sir Can u send me a copy please Tried to but failed I ll pay for that Thanks

[@sasiskas]

sorry, but I have only one. Why did you fail? I can help you if you have any questions

[@marciooppido206]

The problem with this type of circuit is that you do not reset the voltage, and the amperage setting is rubbish.

[@essamfayez1566]

Excellent Fan = volt

[@sundarrajan2054]

Circuit diagram please?

[@sasiskas]

05:21

[@sundarrajan2054]

Thank you...

[@jsrpstatus]

Price

[@sasiskas]

priceless

[@DUNGVO_1990]

😄👍

[@BharathRamMS]

I don't understand why you used two buck converters!

[@sasiskas]

Bharath Ram the small one is needed to power the fan and volt/ammeter display (8v), and the big one is used to control the main output of the bench power supply (0-24v, 0-5A)

[@zipcustoms4584]

Use double sided tape instead of all that hot glue

[@sasiskas]

zip customs I have that hot glue literally for years, wanted to get rid of it. Double sided tape would do the job aswell.

[@46bovine]

Safety shoes????

[@sasiskas]

Robert Vine while using the grinder, I didn't use any PPE, that's why I made a joke about it :-P

[@wastlbastl3965]

du hast auslasslöcher für den lüfter vergessen

[@sasiskas]

thank you for your comment. I thought about the vent holes, but they are really not necessary, under operation the fan lifts the lid (approximately 1-2 millimeters) which works as an exhaust. When the power supply is turned off, the lid is completely closed, preventing dust from entering inside. It is a personal preference, if someone likes to make a few vent holes, it is an easy mod.

[@ardhi1269]

Sfety gloves = skins check✅

[@amtuoni]

only modules

[@tumertech4609]

Fan is useless without vents.

[@sasiskas]

no need vent holes..because the lid get lifted by the air flow. That's one reason for using hinges. that's an advanced venting system 😂

[@imth3onelsi]

what the hell were that noises??

[@sasiskas]

ghosts...I leave in a haunted house 👻

[@imth3onelsi]

@@sasiskas 😂😂😂😂😂😂😂😂😂😂😂😂😂😂you are a hunted man😂😂😂

[@luiserasmo]

Diagrama al minuto 5:22

[@fourlunen997]

P