In case anyone is wondering like I was, if you have a gray wire, you can use that instead of the 2nd red wire he used on one of the LEDs. In this video he used a red wire for his LED, but you can use gray as well! Also the brown wire (3.3 sense), isn't necessarily always brown, it can be orange like mine was. Just look for the brown wire or orange wire that isn't grouped with the other orange wires, that would be your 3.3 sense. Just built mine today, I used crimping instead of soldering, and it's amazing! Very fun project to do! Vielen Dank!
I just built a power supply following (mostly) your video. Danke. BTW: My dummy-load resisters got very hot quickly (>50 C). But, I just stuck them to the metal box with some thermal paste. Now, the whole case is a heat sink for the resisters.
You also get 24V between +12V & -12V. It's limited by current on -12V. And you can add LM317 variable voltage regulator on this output for best result and use.
@Abraham Pardo You can boost the current by changing the rectifier diode on the -12V rail. -12V is taken from 12V winding, it's just rectified in another polarity
What I did is I created a breakout box with the binding posts, fuses and an LED. It accepted a 20-pin connector - this way I can connect any ATX PSU to the box damaging it/cutting any cables :) Also the LED I used is green-red 2-color LED. I wired green to normal 5V rail and red to the standby 5V (always red on standby) via a single transistor and some resistors to the "power good" output - this way the LED is red on standby, green when ready and yellow when it switches on or the rails drift :)
I am totally new to hobby electronics and this looks absolutely awesome!! Uh always wanted to get in the hobby my mother never let me though... Now I have a great journeyman who used to do it to learn from! And this is going to be a first true project for me! Thank you for the video!!! Learned allot from you!
5 years later, thanks :) Couple of points: - Green PS-On wire can be connected directly to the Ground, if you already have the switch on the side of PSU, as I did. One switch less. - My 2 large capacitors are discharged automatically couple of seconds after i turn off the PSU. I've read that good design of good PSU has resistors on each capacitor to drain them. But short them with insulated screw-driver just to be sure. - Soldering such thicc™ wires with 35W soldering iron is really hard. Almost a cold soldering. Better to split the wires in two and wrap them around your binding post, securing with nuts. - My binding post inner core was all metal from the outside. Be sure to insulate it, otherwise it will touch the ground (case) and a short could appear. - Take some really old PSU, preferably with a fan on the side, with more room inside. Chieftec had a huge fan on top, it took space inside, i had to be very careful with wires to fit everything.
You don't need to cut the wires etc. you can search on ebay for "Benchtop Power Board" or similar, you basically connect the 24 pin connector and there, you have a bench power supply with switch, ledy's and binding posts
Beware of these cheap "Benchtop Power Board" from China/Hong Kong. Most of them either do not have fuses at all or the fuse is rated at 5A max which is way less than a PC psu can deliver, so you're limited on what you are going to power with it. Anyway, better be safe than sorry. Also some come with binding posts that are too small and will not accept a standard banana connector. Other than that they cost around $8 USD so for the money they are just OK.
This is essentially what I use since money is tight & electronics is just a hobby. 5V, 3.3V, & 12V are common enough voltages. I've been meaning to do some modifications to get other voltages out of it like 1.2-1.5 & 9, but I haven't gotten to it yet.
+Jonas Offermann Martins and Michael Ding. Welcome to electronics Jonas! The small toggle switch is of a type which is single pole double throw.That means that it only interrupts or controls one leg of the supply, but it can, when needed have two active positions. In this application one terminal of the switch is not used because it is simply being used as an on/off switch. However if you wanted to switch the supply independently to different circuits at different times, then you would use all three terminals. Usually the centre one is common .Michael - a very good point. Perhaps putting some insulating sleeving over the threaded portion of the binding post where it passes through the metal casing would help.Saludos desde el chico electricista.
The Purple wire 5v SB 2amp is great if you have a clock or something you will always need on SB stands for Standby so even when you turn the power off the way you have it and the off switch is not directly after the mains in, it will stay on, awesome for my uses
I was soldering over the internal components like you in 3:17. Then some solder dropped down on to the parts on the circuit board and i can't get rid of it anymore. :( So I recomment you to protect the power supply with a piece of paper. Mine is broken now...
The psu isn't broken, you've bridged something. Use Flux & copper braid /solder mop to mop up the solder. You'll need to resolder any parts you've moped up. Also you can place the psu down on the side being soldered. Lastly solder cools in an instant, unless you use tissue paper it won't burn through.
You might want to use something a little more resistant to heat, like wood. Don't want to be the guy who starts a fire and really destroys their power supply :)
There are two major problems with this idea that I think are serious enough that you shouldn't leave them out from a video like this which influences such a large number of people: 1. While the voltages here are low enough to not be lethal to human beings, the currents that the PSU can provide are dangerous. A typical ATX PSU can commonly provide 50A at the 12V output. That is enough to make any jumper wires, pcb-traces, breadboards, and maybe even proper cables into fuses. I.e. it will melt your circuit possibly causing a fire in the event of a short circuit. You say that the PSU has over-current protection, but that is very misleading when it is unlikely that you will reach the current levels necessary to trigger shutdown. It is likely that you will already have a big mess by then. The whole idea of a "Lab bench" power supply is that it will be used with experimental circuits which may fail, and in that case a proper current limiting is very important. I think it is unfortunate no not bring this up. Besides, the issue could have been mostly solved by adding quick fuses of say 5-10A to the outputs. A simple measure to increase the safety by a lot. 2. Most lab bench power supplies have floating outputs, whereas Computer ATX PSUs have mains-earth-referenced outputs. While this is not a danger per se, I think it is something the viewers should be aware of. A earth referenced output means that the GND output of the PSU is connected to the chassis of all earthed devices in your lab. Again, the voltages are not lethal in this case, but the high currents can definitely cause fires or burns. This means that not only is any dodgy experimental circuit a potential fire hazard, but also any mains-earth-references device around you. The classic one is when probing around with an oscilloscope, which typically has its ground probes tied to mains earth. I don't know if it is possible or safe to disconnect the ATX PSU ground from mains earth and make the PSU floating, and having a mains-earth-referenced PSU is not necessarily a bad thing. But it is significant enough to be mentioned in the video.
That is why i put 5A fuse on 12v rail. And also, on my psu its ays that 12v rail can only output 12A and not more than that beacuse it have current limiter installed in psu
@@ishigamiyu1991 The capacitors in newer psus are usually paired with a drainer that drops the voltage to a safe level in minutes, so no matter how strong the current is it won't get through your skin. And it doesn't necessarily kill you even if you get shocked with a lethal current if the duration is short enough and you are lucky.
Ich finde die Idee richtig super, weil es solche Netzteile schon für sehr wenig Geld gibt, und sich nicht jeder solch ein teures Labornetzteil leisten kann ( möchte ) .
i made one myself but i used giant shrink tube and isolation tape to isolate it,and also added a lamp in the "suicide hole"to light up what i am working with(also has an on off switch)
I red datasheet, and applied dummy load to all power rails : result was a bit more stable.. also those fancy white resistors are usually extremely hot and require a fan to operate well
Like so others can do this if they're not wanting to scrounge around for 10 watt resistors and binding posts. For $7-10 throughout the internet you can find premade PCBs that'll allow you to plug the power supply directly into to convert it into a lab supply. If you're wanting an easier and cost efficient solution I'd recommend doing so.
That was a great video. I've just started getting into electronics a couple of months ago and I've been looking for a cheap alternative to batteries. This is definitely something I'm gonna have to do in the future. Thanks for posting it.
Mine attach a buck & boost converter to 1 of 12v wires, attach a mini av meter, change the trimpot to potensiometer, and ended it on a binding post. Got a 12, 5, 3.3 and variable voltage output
Hey Great Scott. I was wondering if you could make a tutorial on how to design your own circuit from scratch or how to modify one properly? How do you know what components you will need besides resistance and capacity?
Good work To protect the ATX again short circuit. It will be better to connect the Green wire (power on) to Relay contact with black wire. And to energize the relay with the 12 v or 5 v accorditly.
I like the video. OK, ATX-PSU conversions may be an old hat, but the video is well made and edited. Way better then some bad recorded videos in 480p with sound that makes the ears bleeding.... :)
Thank you so much for this! I wish I thought of this before. Power supplies sure are expensive. Thanks to you I will have two power supplies. You've got a new subscriber! :-)
Maybe you should use the gray power_ok cable to power your green led? also mention that you will fry your circuit if something goes wrong since these psu's deliver tons of amps :) i have a bench powersupply and use a atx-powersupply for additional voltages if needed, but i have connected switchable polyfuses to each connector so that i can get a 200mA, 2A or unfused current.
Is it possible to put each wire to a separate post and then use various combinations of wires to achieve different intermediate voltages like 3v, 6v, 8v, 9v, 10v, 12v, 15v, 18v, 20v and so on by using two hot and one ground? Like stacking batteries of different voltages?
Great plug & plag DC PSU DIY. However would be better if you made it variable PSU so that you can control the current. A lot of modern PSU's do 70A+ on the 12V rail.
Hey great video. I`m going to build one of these by myself. One question: Which binding posts exactly do you use? I couldn`t find statisfying once... THX
What does the -12 and -5 do? If I make this and want to power something do I connect it to the -12 and +12 or the +12 and ground? Can I just not use the -12 and -5? THanks
BATMAN You do not have to connect the -12V and -5V. But they are useful if you work with Opamps. If you want for example 12V for your led strip then connect + to +12V and - to GND.
Thanks good vid You could pimp it up with a few volt ammeter things from eBay, maybe add a dial to adjust voltage or amps with a sepic or buck boost. Also I would have kept a few molex connectors and maybe a Sata.
Like you video. I tried to build one of these benchtop power supplies. My power good light keeps blinking. I get all the correct voltage I checked in twice. Can understand why the power good? Led keeps blinking. Yeah, only thing I didn't do is put. A dummy load on the 5 volt Rail. Could that be the problem?
Wonderful video! I'm surprised that I hadn't watched this one yet. One question: What are the other color wires for? +5V SB? PW-OK? Just curious! Considering converting one of my old power supplies into a lab-bench supply after I'm finished replicating your variable lab-bench power supply :) I just need to find the time in the coming weeks to convert the case on an old stereo....
Really awesome ! :D And where do I have to solder the resistors go? :O Must I use the 5w 5 ohm resistors when I have more amps at 5 volts? Or change only the output voltage?
nicholas scott duhhh,ur a noob at electronics but hey everyone has to learn one way or another,a 200ohm resistor on leds,a 0-5Kohm resistor for your power supply,it depends on the amperage,wattage,and voltage your power supply needs,just look up on google e.x "what kind of resistor is needed for 12v 5amp 45w power supply?",then find it,boom order it,and when u get it,add it in your project whenever u wanna work on it,your welcome from a friendly electronics enthusiast
This may be a stupid solution, but you can get a power supply from nothing more than a train set, just connect a couple of jumpers to the track connections, and ramp up the power, if you get the right supply, like Athearn or railpower, they have a case mounted shut off switch
Thank you for the DIY tutorial - Works for me just fine, tested led strip on the 12 works I thought the strip woud glow on the 5v and the 3.3v atleast a bit but it doesnt wonder why ? there is power to the 5 and 3.3v but the 12v strip doesnt even glow slightly on them .
Georgi Tuleshkov Only a red (and orange) strip would light up a little bit with 5V. All the other colors have a higher forward voltage. So don't worry. That is normal
Yes, you are right, I tested it with a green diode which gave out yellow colour on the 3.3v orange at the 5v and fiery glow at the 12v and burned out :D, thanks for the great vid :)
Hi great job! I think you forgot to add labels to the output posts to see which post delivers which voltage but other than that it is great thanks! ;-)
Hello Scott. First of all, Congrats for the great channel, thanks for all your inspirationnal videos ! I am builind my power supply with the same principle, but I would like to have an ajustable Channel. I was thinking about wiring a +12 and a +5 of the PSU in series to get 17V and then adjust it with a transistor which I would command in PWM (arduino ...). Do you think that would be a good idea ? Thanks ! :) EDIT : Just realize my question was silly. You can't wire 12 and 5 in series cause that would mean shorting +5V or +12V to the GND !!!
Nice video! Thanks! Question: What wattage were those 220ohm resistors? I was looking for some and I see 1/8, 1/4, 1/2, 1w ... I am not sure what ones I should be using. Thanks!
Nice tutorial but one objection though.Maybe the dummy load shouldnt be wraped in tape because of the heat that it will produce, wouldnt it be better to mount it somehow in the chassis of the psu?
You can tell: If your PSU has more Power in the 5V Rail, you need a dummy load, if it has more power on the 12V Rail, you don't. Most modern (quality) Supplys work fine without any load.
Scott, mostre-nos como montar uma fonte deste tipo, simétrica, para amplificadores. Eu estava pensando em fazer uma com Arduino, mas é um projeto audacioso demais para um hobbista. Um abraço direto do Brasil! Sucesso!
Thanks for this video! Also, what do I do with the tiny left wires? Gray, brown, black and jointed black and white? They are not the fans ones since the fans are already connected.
When I turn on the power supply it works but when I start applying load to the 12v output it stops the power supply at around 0.2 amps. Any idea why? I tried using the 12v 8amp and 12v 14amp output.
Big fan! Would it be possible to create a power delivery usb charger out of a psu? And what would be the maximum pd volt and amp it can supply? I have a psu and i am thinking of creating a pd station to supply my dell laptop 130 watt, pi4 and two phones.
in order to have standard or the same at all time load on the power supply can i use one more fan instead of the resistor correct me if i am wrong and in mine i have to connect the green(power on) and the black(ground) in order to activate the power supply how you did that i didnt understand did u use an other method?
Hi Scott, great video as always! I love you channel, thank you for sharing your knowledge so openly. I have a question. I made my ATX bench, and all the outputs are ok, but with a slight instability in tension, like +/- 0.02 volts, and when I want to use it to power my servomotors (controlled by Arduino), this slight instability makes my servos jitter very hard. Do you know what can be de cause and/or solution to this? Thanks in advance everyone!
In case anyone is wondering like I was, if you have a gray wire, you can use that instead of the 2nd red wire he used on one of the LEDs. In this video he used a red wire for his LED, but you can use gray as well! Also the brown wire (3.3 sense), isn't necessarily always brown, it can be orange like mine was. Just look for the brown wire or orange wire that isn't grouped with the other orange wires, that would be your 3.3 sense. Just built mine today, I used crimping instead of soldering, and it's amazing! Very fun project to do! Vielen Dank!
I made this project, turned out really cool and it comes very handy to supply my 100w led with it's demanding Amperage
Current*
would be cool to have a remake of this video. You sound like you haven't had your morning cup of coffee yet. :P
whoa no need to get excited
yess
idk i kinda like the more chill Great Scott
Totally agree
@@camilomason4560 to ciekawe
This is great. I just built mine and it works perfectly. Thanks GreatScott!
Viwe Mqaqa i wonder if its powerful enough to jumpstart a truck
Meh. I use 50's Tesla BS 275. 0-800V
@@rosekreuze it will pop
Also, add 5-10A fuses
I just built a power supply following (mostly) your video.
Danke.
BTW: My dummy-load resisters got very hot quickly (>50 C). But, I just stuck them to the metal box with some thermal paste. Now, the whole case is a heat sink for the resisters.
You also get 24V between +12V & -12V. It's limited by current on -12V. And you can add LM317 variable voltage regulator on this output for best result and use.
@Lenin Pardo Salazar yes, I mentioned it...
@Abraham Pardo You can boost the current by changing the rectifier diode on the -12V rail. -12V is taken from 12V winding, it's just rectified in another polarity
That limits the current to 800mA... Seems booooring when you have 20 amps on the positive 12 volt rail.
What I did is I created a breakout box with the binding posts, fuses and an LED. It accepted a 20-pin connector - this way I can connect any ATX PSU to the box damaging it/cutting any cables :) Also the LED I used is green-red 2-color LED. I wired green to normal 5V rail and red to the standby 5V (always red on standby) via a single transistor and some resistors to the "power good" output - this way the LED is red on standby, green when ready and yellow when it switches on or the rails drift :)
I am totally new to hobby electronics and this looks absolutely awesome!! Uh always wanted to get in the hobby my mother never let me though... Now I have a great journeyman who used to do it to learn from! And this is going to be a first true project for me! Thank you for the video!!! Learned allot from you!
5 years later, thanks :) Couple of points:
- Green PS-On wire can be connected directly to the Ground, if you already have the switch on the side of PSU, as I did. One switch less.
- My 2 large capacitors are discharged automatically couple of seconds after i turn off the PSU. I've read that good design of good PSU has resistors on each capacitor to drain them. But short them with insulated screw-driver just to be sure.
- Soldering such thicc™ wires with 35W soldering iron is really hard. Almost a cold soldering. Better to split the wires in two and wrap them around your binding post, securing with nuts.
- My binding post inner core was all metal from the outside. Be sure to insulate it, otherwise it will touch the ground (case) and a short could appear.
- Take some really old PSU, preferably with a fan on the side, with more room inside. Chieftec had a huge fan on top, it took space inside, i had to be very careful with wires to fit everything.
Watching your channel and yourself grow has been a privilege. You have come a long way keep up the good work mate! =D
Thanks
Johann Wyss Same
Maaan I was twanted to do this for over a year and today I finally did it! Amazing!
First time and everything works yeaaa it's a good feeling.
You don't need to cut the wires etc. you can search on ebay for "Benchtop Power Board" or similar, you basically connect the 24 pin connector and there, you have a bench power supply with switch, ledy's and binding posts
I wish I read that earlier
dammnit..i didn't see this comment before i got stuff.
There's anything like that but with an integrated step-up step-down to obtain a variable output?
Beware of these cheap "Benchtop Power Board" from China/Hong Kong. Most of them either do not have fuses at all or the fuse is rated at 5A max which is way less than a PC psu can deliver, so you're limited on what you are going to power with it. Anyway, better be safe than sorry. Also some come with binding posts that are too small and will not accept a standard banana connector. Other than that they cost around $8 USD so for the money they are just OK.
This is essentially what I use since money is tight & electronics is just a hobby. 5V, 3.3V, & 12V are common enough voltages. I've been meaning to do some modifications to get other voltages out of it like 1.2-1.5 & 9, but I haven't gotten to it yet.
There is also a kit sold by Adafruit that outputs to 3.3, 5, or any other voltage from a barrel jack.
Thank you you show how easy this can be for us beginners.
+Jonas Offermann Martins and Michael Ding. Welcome to electronics Jonas! The small toggle switch is of a type which is single pole double throw.That means that it only interrupts or controls one leg of the supply, but it can, when needed have two active positions. In this application one terminal of the switch is not used because it is simply being used as an on/off switch. However if you wanted to switch the supply independently to different circuits at different times, then you would use all three terminals. Usually the centre one is common .Michael - a very good point. Perhaps putting some insulating sleeving over the threaded portion of the binding post where it passes through the metal casing would help.Saludos desde el chico electricista.
The Purple wire 5v SB 2amp is great if you have a clock or something you will always need on SB stands for Standby so even when you turn the power off the way you have it and the off switch is not directly after the mains in, it will stay on, awesome for my uses
thanks i hade no idea and run a second 5v power supply
I was soldering over the internal components like you in 3:17. Then some solder dropped down on to the parts on the circuit board and i can't get rid of it anymore. :( So I recomment you to protect the power supply with a piece of paper. Mine is broken now...
The psu isn't broken, you've bridged something. Use Flux & copper braid /solder mop to mop up the solder. You'll need to resolder any parts you've moped up. Also you can place the psu down on the side being soldered.
Lastly solder cools in an instant, unless you use tissue paper it won't burn through.
F
You might want to use something a little more resistant to heat, like wood. Don't want to be the guy who starts a fire and really destroys their power supply :)
@@kingarthurthe5th "Use wood" " Don't start a fire" :P
Use a toothpick to remove the solder, of course heat it up before
There are two major problems with this idea that I think are serious enough that you shouldn't leave them out from a video like this which influences such a large number of people:
1. While the voltages here are low enough to not be lethal to human beings, the currents that the PSU can provide are dangerous. A typical ATX PSU can commonly provide 50A at the 12V output. That is enough to make any jumper wires, pcb-traces, breadboards, and maybe even proper cables into fuses. I.e. it will melt your circuit possibly causing a fire in the event of a short circuit. You say that the PSU has over-current protection, but that is very misleading when it is unlikely that you will reach the current levels necessary to trigger shutdown. It is likely that you will already have a big mess by then.
The whole idea of a "Lab bench" power supply is that it will be used with experimental circuits which may fail, and in that case a proper current limiting is very important. I think it is unfortunate no not bring this up. Besides, the issue could have been mostly solved by adding quick fuses of say 5-10A to the outputs. A simple measure to increase the safety by a lot.
2. Most lab bench power supplies have floating outputs, whereas Computer ATX PSUs have mains-earth-referenced outputs. While this is not a danger per se, I think it is something the viewers should be aware of. A earth referenced output means that the GND output of the PSU is connected to the chassis of all earthed devices in your lab. Again, the voltages are not lethal in this case, but the high currents can definitely cause fires or burns. This means that not only is any dodgy experimental circuit a potential fire hazard, but also any mains-earth-references device around you. The classic one is when probing around with an oscilloscope, which typically has its ground probes tied to mains earth.
I don't know if it is possible or safe to disconnect the ATX PSU ground from mains earth and make the PSU floating, and having a mains-earth-referenced PSU is not necessarily a bad thing. But it is significant enough to be mentioned in the video.
That is why i put 5A fuse on 12v rail. And also, on my psu its ays that 12v rail can only output 12A and not more than that beacuse it have current limiter installed in psu
You must have the most "engineeresque" community on TH-cam. Subscribed. :)
I like the acid music..
Good tutorial also.
Wow whops that hurt just got shocked by 240V from toying around with the computer power supply . be carefull people that do this
did u touch the capacitors?
CarterGonta i gotta thank you for your sacrifice! good job!
@@bubbadam1589 he wouldn't be messaging if he did
@@__MINT_ fr dude? °O°
@@ishigamiyu1991 The capacitors in newer psus are usually paired with a drainer that drops the voltage to a safe level in minutes, so no matter how strong the current is it won't get through your skin. And it doesn't necessarily kill you even if you get shocked with a lethal current if the duration is short enough and you are lucky.
Ich finde die Idee richtig super, weil es solche Netzteile schon für sehr wenig Geld gibt, und sich nicht jeder solch ein teures Labornetzteil leisten kann ( möchte ) .
Thanks! My first attempt at one....had to wait until the 5ohm resisters came in.....but works really well!!!
you always have wonder videos. I cant get enough
Great scott has gone from king of jank to eletrical engineer in these past years lol.
What a great video, today i finished my own ATX bench power supply, it turned out great. Thanks for this video :)
i made one myself but i used giant shrink tube and isolation tape to isolate it,and also added a lamp in the "suicide hole"to light up what i am working with(also has an on off switch)
I red datasheet, and applied dummy load to all power rails : result was a bit more stable.. also those fancy white resistors are usually extremely hot and require a fan to operate well
Great work I saved 200 dollars cheers
Like so others can do this if they're not wanting to scrounge around for 10 watt resistors and binding posts. For $7-10 throughout the internet you can find premade PCBs that'll allow you to plug the power supply directly into to convert it into a lab supply. If you're wanting an easier and cost efficient solution I'd recommend doing so.
These are available on eBay for less than £6. Just search for "atx breakout board"
Just got one and I've had no issues with it so far. Just a bit of wire management and I think she'll do.
That was a great video. I've just started getting into electronics a couple of months ago and I've been looking for a cheap alternative to batteries. This is definitely something I'm gonna have to do in the future. Thanks for posting it.
I made one a few years back with your help thanks good channel
You could also add a potentiometer and a voltage reader panel and you could use that as a variable supply
Just build this and it works GREAT! Thanks for this!
i created mine with 8 terminals (3x GND), ok, led and iluminated switch... while closing it was like packing full suitcase before vacation :D
Mine attach a buck & boost converter to 1 of 12v wires, attach a mini av meter, change the trimpot to potensiometer, and ended it on a binding post.
Got a 12, 5, 3.3 and variable voltage output
Thanks for the tutorial - just made one myself this afternoon using your guidance.
Hey Great Scott. I was wondering if you could make a tutorial on how to design your own circuit from scratch or how to modify one properly? How do you know what components you will need besides resistance and capacity?
GreatScott!
+GreatScott!
+GreatScott! :P
Vaes Joren Thanks👍
Probably doesn't want his viewers to die haha
Good work
To protect the ATX again short circuit. It will be better to connect the Green wire (power on) to Relay contact with black wire. And to energize the relay with the 12 v or 5 v accorditly.
Hey great scott!! Its time to revisit this project and make it better. Or even diy vs buy?
Oh this is an old video :') the feels
Great video. I hope to build one of these in the future.
What about the short circuit and over-current protection on those outputs ? Does PSU have those inbuilt ?
Yes
congratulations for your work, and thank you for share this information, excellent project
would a 10w 5ohm resistor work well as a dummy load or do I need those exact ones? awesome video and thanks for any help!
Thanks for the great vid! Your video tutorial worked like a charm and a 15A ATX power supply now gives enough juice to run two lipo smart chargers :-)
Nice project
I like the video. OK, ATX-PSU conversions may be an old hat, but the video is well made and edited. Way better then some bad recorded videos in 480p with sound that makes the ears bleeding.... :)
Could you make a 0-36v 3a variable power supply?
mondrota That is one of my current projects. Check out my facebook site to see some pics.
I am currently working on a power supply like this as an addition to my variable one
Thank you so much for this! I wish I thought of this before. Power supplies sure are expensive. Thanks to you I will have two power supplies. You've got a new subscriber! :-)
Maybe you should use the gray power_ok cable to power your green led?
also mention that you will fry your circuit if something goes wrong since these psu's deliver tons of amps :)
i have a bench powersupply and use a atx-powersupply for additional voltages if needed, but i have connected switchable polyfuses to each connector so that i can get a 200mA, 2A or unfused current.
do I have to do the dummy load?
I just connected the PSU's fan into the 12v wire and it works fine.
0:58
Didn't expect the blue light!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Cool video and idea thanks
Does somebody know where i can get these connectors from? :D
Very nice power supply but only thing we can't get 6 and 9 volts which are also needed sometimes
oh wow, i messed up my old ATX supply just like you did, burning short wires with it heh
Nice! Go mains 220 50/60 hz isolated to 60 volts at 0 to 6 amps adj V adj current limiting. SMPS in small package.
got me one built! just finished it today :) thanks man!
This is great, greatscott.
can i use the 12v dc for 12v 15w hologen blub
How much heat will be dissipated from the dummy load if we run it for a long time? Does the dummy load need a heat sink?
Is it possible to put each wire to a separate post and then use various combinations of wires to achieve different intermediate voltages like 3v, 6v, 8v, 9v, 10v, 12v, 15v, 18v, 20v and so on by using two hot and one ground? Like stacking batteries of different voltages?
Great plug & plag DC PSU DIY. However would be better if you made it variable PSU so that you can control the current. A lot of modern PSU's do 70A+ on the 12V rail.
Connect lots of capacitors in series, and blow them all up!
lol I'd like to do that someday
+NItro Cat only one would blow then there is No more connection. connect in parralel then IT works
+Der Tyros You are reducing the capacitance when the caps are in series, so it should blow up quicker, no?
Spoder Man
idk man
Can i use this without the dummy load?
Hey great video. I`m going to build one of these by myself.
One question: Which binding posts exactly do you use? I couldn`t find statisfying once...
THX
A great video i now remember how to power my old one on again
superb video
What does the -12 and -5 do?
If I make this and want to power something do I connect it to the -12 and +12 or the +12 and ground? Can I just not use the -12 and -5? THanks
BATMAN You do not have to connect the -12V and -5V. But they are useful if you work with Opamps. If you want for example 12V for your led strip then connect + to +12V and - to GND.
If you have to ask this then you probably shouldn't be attempting any projects just yet. Time to go learn a bit of theory first.
Thanks good vid
You could pimp it up with a few volt ammeter things from eBay, maybe add a dial to adjust voltage or amps with a sepic or buck boost. Also I would have kept a few molex connectors and maybe a Sata.
No need for dummy load, hook the fan for constant operation.
@greatscott! do you agree?
Like you video. I tried to build one of these benchtop power supplies. My power good light keeps blinking. I get all the correct voltage I checked in twice. Can understand why the power good? Led keeps blinking. Yeah, only thing I didn't do is put. A dummy load on the 5 volt Rail. Could that be the problem?
Wonderful video! I'm surprised that I hadn't watched this one yet.
One question:
What are the other color wires for? +5V SB? PW-OK? Just curious! Considering converting one of my old power supplies into a lab-bench supply after I'm finished replicating your variable lab-bench power supply :) I just need to find the time in the coming weeks to convert the case on an old stereo....
+5V SB is 5v standby wire and it gives aoutput when pc is off
Really awesome ! :D
And where do I have to solder the resistors go? :O
Must I use the 5w 5 ohm resistors when I have more amps at 5 volts?
Or change only the output voltage?
I asked a similar question.... Did you find out???
Well now i have 2 lab power supplys for that kind of stuff.
But anyway good to know 5 years later. :'D
do all power supply need a resister
nicholas scott duhhh,ur a noob at electronics but hey everyone has to learn one way or another,a 200ohm resistor on leds,a 0-5Kohm resistor for your power supply,it depends on the amperage,wattage,and voltage your power supply needs,just look up on google e.x "what kind of resistor is needed for 12v 5amp 45w power supply?",then find it,boom order it,and when u get it,add it in your project whenever u wanna work on it,your welcome from a friendly electronics enthusiast
This may be a stupid solution, but you can get a power supply from nothing more than a train set, just connect a couple of jumpers to the track connections, and ramp up the power, if you get the right supply, like Athearn or railpower, they have a case mounted shut off switch
Thank you for the DIY tutorial - Works for me just fine, tested led strip on the 12 works I thought the strip woud glow on the 5v and the 3.3v atleast a bit but it doesnt wonder why ? there is power to the 5 and 3.3v but the 12v strip doesnt even glow slightly on them .
Georgi Tuleshkov Only a red (and orange) strip would light up a little bit with 5V. All the other colors have a higher forward voltage. So don't worry. That is normal
Yes, you are right, I tested it with a green diode which gave out yellow colour on the 3.3v orange at the 5v and fiery glow at the 12v and burned out :D, thanks for the great vid :)
Hi great job! I think you forgot to add labels to the output posts to see which post delivers which voltage but other than that it is great thanks! ;-)
Hello Scott. First of all, Congrats for the great channel, thanks for all your inspirationnal videos ! I am builind my power supply with the same principle, but I would like to have an ajustable Channel. I was thinking about wiring a +12 and a +5 of the PSU in series to get 17V and then adjust it with a transistor which I would command in PWM (arduino ...). Do you think that would be a good idea ? Thanks ! :) EDIT : Just realize my question was silly. You can't wire 12 and 5 in series cause that would mean shorting +5V or +12V to the GND !!!
Nice video! Thanks!
Question: What wattage were those 220ohm resistors? I was looking for some and I see 1/8, 1/4, 1/2, 1w ... I am not sure what ones I should be using. Thanks!
those are usually 1/4w
Nice tutorial but one objection though.Maybe the dummy load shouldnt be wraped in tape because of the heat that it will produce, wouldnt it be better to mount it somehow in the chassis of the psu?
Sure
why should you use a dummy load?
The psu has to have some load, otherwise it will not turn on.
Mighty Doge atleast my older psus will turn on with a paperclip but i think the newer ones need it to balance the power or something
angrycreeper100 On the new ones you have to short green with ground and have some load attached
You can tell: If your PSU has more Power in the 5V Rail, you need a dummy load, if it has more power on the 12V Rail, you don't.
Most modern (quality) Supplys work fine without any load.
Scott, mostre-nos como montar uma fonte deste tipo, simétrica, para amplificadores. Eu estava pensando em fazer uma com Arduino, mas é um projeto audacioso demais para um hobbista.
Um abraço direto do Brasil!
Sucesso!
Boa!
This is good for most electronic projects but not recommended on rf and ham radio circuits.
rene kenshin Well don't know about radio, but a 750W Thermaltake works well for my Kenwood amplifier
Of course. Bcse is a switching power supply. For those projects you need a linear(with big trafo) with little ripple and noise
What if i put 12ohms to the 5v rail as dummy load,or 30ohms to the 12v rail as dummy load.and can i use this power supply to power arduino ?
for what is the resistor at the 5v or 12v?
And can I use the voltages simultaneously to power up different devices in a circuit?
Thanks for this video! Also, what do I do with the tiny left wires? Gray, brown, black and jointed black and white? They are not the fans ones since the fans are already connected.
What is the brown wire. I don't see it in my supply and want to make one
When I turn on the power supply it works but when I start applying load to the 12v output it stops the power supply at around 0.2 amps. Any idea why? I tried using the 12v 8amp and 12v 14amp output.
+Attila P. U must load the 5v line to 12v line work properly.
Is the big resistor really required? I dont have any but have everything else.
Thank You, I have an SMPS. & I will do this . Can i use 4.7 ohm 5 watt Resistor
Big fan!
Would it be possible to create a power delivery usb charger out of a psu? And what would be the maximum pd volt and amp it can supply? I have a psu and i am thinking of creating a pd station to supply my dell laptop 130 watt, pi4 and two phones.
in order to have standard or the same at all time load on the power supply can i use one more fan instead of the resistor correct me if i am wrong and in mine i have to connect the green(power on) and the black(ground) in order to activate the power supply how you did that i didnt understand did u use an other method?
Mine has 20A on the 5V side and 15A on the 3.3V side, and only 10A on the 12V side.
So i need to put the load on the 3.3V/5V side, right??
Nice project! Wouldn't it be safer to add fuses (like 5amps ones), so you don't damage the PSU when drawing too much current?
***** They usually have an overload and short circuit protection.
@@greatscottlab They do, but many ATX PSUs can provide around 55A @12V. That is enough to melt most wires, breadboards etc.
@Karl Ljungkvist no way, that's scary asf.
Hi Scott, great video as always! I love you channel, thank you for sharing your knowledge so openly.
I have a question. I made my ATX bench, and all the outputs are ok, but with a slight instability in tension, like +/- 0.02 volts, and when I want to use it to power my servomotors (controlled by Arduino), this slight instability makes my servos jitter very hard.
Do you know what can be de cause and/or solution to this?
Thanks in advance everyone!