Modifying a Computer ATX Power Supply For Higher Output Voltage

[@theosong2244]

Thanks Kerry, it helped me to modify my ATX-330BT. The +12V rail went up to 26V and blew up some elco's. I had them all replaced for higher voltages.

[@Inspironator]

Thanks for showing this. I like how simple your mods were to change the output voltage as well as the overvoltage protection. Elegant solution!

[@KerryWongBlog]

Thanks!

[@hedi875]

Works very good. Have installed a variable resistor to get exactly 15v as output. Thanks Kerry Wong.

[@hanggliding5887]

at time 8:18 the resistor you put on leg 1 to the i c is 15 kilo ohm not 2.2 kilo ohm please check it again !!!!!!!! it was helpful and easy great job thanks !!!!!!!!!

[@mabul513]

Theres digital power supply with dial and voltage goes to 24v from certain online stores. Excellent when plugged in also show the power of item you connect. So batteries will come up at how charged they are. Best 10$ spent 9/24 volts at 3 amps. Digital readout.

[@Imdadkhan-ub4ec]

Hi, i am also having experience in modifying smps ... But i get a problem of reverse voltage from battery. You put diod in this video. Can you guide me how to connect DIOD to positive wire of the battery to stop reverse current

[@shodanxx]

Why do you state that the external case can become a danger of electrocution ? You seem to still have the external case grounded ? So it would blow the breaker before raising the voltage of the case (the case cannot have high voltage without raising the voltage of ground, which would require a lot of current)

[@arwisawhie7562]

Kerry, Thank you for your time and sharing. Good Job

[@felixcat4346]

I liked this modification but it would be so much better if you could demo a circuit which would adjust current and voltage. You could also utilize the other voltage capabilites of ATX power supplies. For example, it provides minus 12 volts at a lower amperage so if you could live with this limitation it would put out alot more voltage.

[@jcgarcia4575]

When you disconnect pin 4 of tl494 it will be direct on when you plugged it

[@leozendo3500]

Should I mod the primary side(near IC) or the secondary side(TL437 control pin) if it uses a TL437 as voltage reference for maximum voltage swing? In addition, is there a way to change its current limit too? Most supplies do not use a current shunt and instead uses fancy feedbacks. So it's not as easy as modding a op amp. I am planning to power the control circuitry with aux power if the original topology does not allow the output voltage to go too low. It's usually the best if you can find a PSU that has aux power built-in.

[@hisashime]

Thanks for the simplicity of just 2 resistor and a diode to make the modification.

[@KerryWongBlog]

You are welcome!

[@osmanozutemiz1366]

Hey man you pull down tl494's dead time pin to ground with 3.3k. This will means 0 dead time and there will be short circuit on primer mosfets. You should apply some voltage to dead time pin to make dead time different from zero and prevent shorts. Please answer.

[@omsingharjit]

But after modification , that circuits over voltege and current protection work for modified output voltage , like 14.5 voltage ??

[@jacktheninja]

nope, he said you would have to disable it

[@omsingharjit]

@@jacktheninja what's why it burned my many 13007 whenever I tryed to play by shortcut its outputs :(

[@omsingharjit]

He disabled ovp but I want to know about ocp ?

[@jacktheninja]

@@omsingharjit oh yeah i am researching more until i preform this mod

[@jacktheninja]

@@omsingharjit so doe this work?

[@sciencegadgetry]

I believe I have that same power supply, but I have a question: I want to vary from about 3-12 V instead of going high as you did. How would I go about it?

[@rozarijorodin]

Okay...great job... When I put up few volts (16-17V) Why those big resistors on output are getting so hot...?

[@SyedAli-nr3if]

Can i connect the PSU yellow 12w and the 3.3v in series in order to get 14.4 or 14.3 volts will this technique damage the PSU FOR DC motor...this is for powering the DC motor

[@andytipping70]

WONT WORK AS THERES NO WAY TO SEPARATE THE GROUND - THEY ARE COMMONED

[@jmillard34]

What is the model number of the clamp meter?

[@hichamtassi1753]

Hello, Nice video ! i would like to disable the OCP on a TPS3513 on the 12v rail. My confusion is whether to ground the pin 5, unsolder it, or cut the pcb trace to it. Changing the voltage is done but at heavy loads the OCP kicks in and turns of the PSU. Thanks if someone can help !

[@mtrltoolman]

Did you solve this problem?

[@hichamtassi1753]

@@mtrltoolman yes. I grounded it.

[@injoelsgarage3934]

Kerry, Thank you for your time and sharing. Joel

[@KerryWongBlog]

You are welcome Joel!

[@TEREZKATERKA100]

Super. Prvá úprava, ktorá funguje na prvé zapojenie. Treba si dať pozor a nastaviť potenciometer, aby sme neprekročili napätie elektrolytických kondenzátorov. Akými odpormi ste zaťažili výstupy 12 V a 5 V ?

[@iikmubarakachmad3054]

fantastic job

[@mrdesperate6534]

Is there a solution to regulate the voltage below 4.7 to get 0 volts I got max voltage 24 V and minimum voltage 4.7 I want to get voltages below 4.7

[@rhiantaylor3446]

I didn't hear anything about how you limited the charge current - you told us the current your batteries drew and that the PSU could cope but what is the batteries cannot cope with such a high charge current - is that also a BMS function ?

[@technology520]

Hello! I ask you two questions; 1-Is there protection when over current is drawn from the source? If the 2-14,6V output is short circuit, does the source protect itself?

[@rimurutempest8881]

although it's been a year,, regarding to your questions, the answer is yes , the atx Power supply has over voltage and over current protection and I already tested it but some atx Power supply doesn't have that feature

[@dehydratedwatr]

Where does one go to find Data Sheets? Each time I go on a hunt, it begins with google but ends in frustration with no data. Thank You...

[@johnmason2583]

Hi Kerry, Does this modification alter the voltages on the other rails?

[@FrancisRodgers]

Great video. Thanks for sharing. Could you replace the first resistor with a pot and make it variable? Also does modifying the 12V rail like this, also affect the 5 and 3.3 rails (perhaps making them 6 and 4 or whatever)?

[@khanhninham4889]

you can modify an atx ps to get 28v and at least 5A output by change the -12v line diodes (typically, the two FR107 diodes)

[@cood22]

Those wires and connections to the battery terminals seem to be a bit on the thin side for the current. Have you measured the voltage drop?

[@KerryWongBlog]

Those are actually two 16 AWG wires, which should be more than enough for the 12A maximum current. BTW, I just measured the current drop it's around 15mV give or take when the current is at 10A.

[@Tsachyl]

At 15A load I get 0.7v sag. Is this normal?

[@santiagopicco1397]

@@Tsachyl it depends on the cables, It could be. However, for this porpuse, voltage drop does not mean that much since when you are topping of the battery, the current will be close to cero, there neglecting any voltage drop.

[@sumitchaudhary8489]

The value of resistors is differ than you told in the video, you said 2.2kilo ohm but the restance you used is 15 kilo ohm actually. I am confused??

[@eko653]

Could this atx be modified for 14s or 7s li-ion?

[@randallmarsh446]

CAN AN ATX POWER SUPPLY BE MODIFIED TO HAVE AN OUTPUT OF 110 VOLTS DC?

[@nuwanweerakkody2985]

I have confusion with resister values, could you reply with actual values of them in your built unit for 14.6V output? thanks a lot.

[@BWWGL9]

Mr. Wong, I have a"ISDT Q6 Pro 300W/14A'..Lipo Smart charger, that run off of DC 7-32v DC INPUT. I want to Buy a External Power Supply, so I can use this Charger on my bench using AC power. A AC to DC Power Supply. An sense the DC Input is 7-32V, I can use a 12v or 24v input power source. I'm just no sure, if I should get lets say a 12v 300 watt power supply, or something like a 24V 480 watt Power Supply. I'll be charging (2) Lipo 3S 5000mah 11.1 volt batteries, at the same time, using a Parallel Board. What would be the most efficient and effective External power supply in your option? Any help is appreciated. THANKS

[@KerryWongBlog]

I'd get the 24V PS for your use as typically the higher the input voltage the more efficient for switching DC/DC converters (in this case your Lipo charger).

[@donaldhenke2750]

I have a atx power supply that will not take 6amps without turning it off then connecting the load then it works. if i dont turn it off before i connect the load it shuts down. any ideas?

[@forummejl4468]

Is there a way to increase just maximum allowed current and all other to stay the same ? Because I use 12 volts and power supply shuts down when I connect something like cordless drill .

[@KerryWongBlog]

This will depend on your power supply unfortunately. Alternatively, you could try putting a small resistor in series with your drill (say 0.1 to 0.5 Ohm is usually sufficient) and this limits your maximum current draw without affecting the operation of your drill much. Better yet, you could put a 1000uf capacitor after the series resistor so that the initial in-rush current can be supplied by the capacitor.

[@tofichannel3488]

Thanks bro its work this is the good idea for desactivat the protection systeme i search for 3 month and i dosn't find theme Thank yu lot .

[@KerryWongBlog]

You are welcome!

[@tjsin59]

would you be able to take the output of the 3.3 volt and the 12 volt and run it as 15ish volts ? im thinking more of an additional part , anyway safely to do this ? thanks again

[@BurrowsNE]

No. 3v and 5v are taps from the 12v. Take a look at a voltage devider circuit and it will make sense. Basically the 3v and 5v are divided from the 12v. 12 - 3 + 3 = 12.

[@enochfuryan9094]

Great video. I would like to suggest you do a video an adjustable bench supply from a PC supply in the same way (if possible). Thanks!

[@KerryWongBlog]

Thanks! Most PC power supplies are not that adjustable so what most people do usually is to have a second stage of linear regulator (or another adjustable switching regulator) in series with the main output.

[@prof8957]

Nice and clear! Sadly, no mention of the Schottky diodes and how they were installed.

[@n3tpr0b3]

Hey Kerry, I'm curious about one thing. Does the BMS take care of the charging curves (first CC, then CV then Trickle) for the battery ?

[@KerryWongBlog]

Unfortunately, no. It only takes care of balancing the cells after the charging is done. There's nothing wrong with current limited charging for LiFePO4 or Li-Ion batteries, it just takes longer.

[@n3tpr0b3]

Yeah, I agree, CC and CV will be enough. The power supply is limiting the current? I might have missed that in your video.

[@KerryWongBlog]

Well, the maximum rated current on the 12V supply rail for this particular power supply is 11A, so it limits the current to some degree. If the power supply can deliver more current than that, you will have to add a small resistor in between.

[@n3tpr0b3]

Oh, I thought you made a constant-current mode for the PSU. I'd check the current/voltage waveforms when it's charging the battery pack when it's depleted (so maximum current). I've never seen any computer PSU with a CC function. When there is an over current, the PSU simply goes in to burst mode, and this will be terrible for the battery.

[@AndreasMaeurer]

Great Video! Would it be possible to increase the voltage all to way to 18 volts? Or is that not possible with this powersupply?

[@rimurutempest8881]

use DC to DC step up Boost converter

[@AndreasMaeurer]

@@rimurutempest8881 Is there a DC to DC step up Boost converter that you could recommend?

[@Yorumcu63]

Great video

[@SeAfasia]

thanks for share those informations...they are very helpfull to us Kerry....Kostas..!!

[@KerryWongBlog]

You are welcome!

[@naderhumood]

Modification is great thanks v much . I needs extra care. .👍

[@45llamas]

Nice video man! I've been looking to do this for a while. I have a Corsair TX650M and I want to increase the voltage to 14v but i don't know if it is possible in this modern ones

[@KerryWongBlog]

Well, it depends on what's the mechanism for the overvoltage protection. On some power supplies, dedicated ICs are used and there's no way to adjust the threshold. So it depends.

[@islam506]

Мне нужна схема на блок питания aerocool e80-600 если у вас есть то поделитесь со мною . Мой блок уходит в защиту при включении дергает фен и все . Проверил многое но не чего не нашёл . Может ли быть причиной супервайзер ?

[@UniCrafter]

I spent ages looking for cheap, high current battery chargers, all cost ~$1 per watt without it being alibaba or something. Brand new computer power supplies even are $1 per 8 watts from good brands, which is fantastic compared with battery chargers. Definitely giving this a shot.

[@powerelectronics8640]

Great👍👍👍❤️

[@brittainmedia2569]

Theres a bad solder joint in the lower right corner where.the two resistors are installed

[@supreetyadav5021]

Use a 10a boost converter with constant current folks, much easier and safer

[@gustavo123ar]

Great Video!

[@hichamtassi1753]

Hello, nice video ! i have an old PSU unit from DELL, my PFC burnt, do you think it is safe to remove it ? it blows all the fuses. thanks

[@irawarnaca8133]

Nice job!

[@robertcartier5088]

Cool idea, Thanks!

[@tluva1020]

Did you just gargle Marlboros & glass?? Can't get through it

[@donaldhenke2750]

why a atx psu will not take 6amp load when its allready on

[@mataokiskill4fun437]

cuz is old and cheap

[@meddiys6171]

Nice video go on.

[@SirWolfCZ]

9:10 I see a cracked joint in the bottom right corner :)

[@andiyladdie3188]

I think that must be heatsink post for secondary rectifier Schottky diodes, not a big deal, that is not connected to nothing, is soldered just to provide an anchor point for the heatsink to the pcb.

[@LogicWheels]

Why disabling the overvoltage protection completely? Wouldn't it be safer to insert a voltage divider that has an output of 12 volts towards the OVP pin of the chip? That way, if an overvoltage occurs, the power supply will still shutdown. A safer solution then disabling the OVP completely imho.

[@KerryWongBlog]

You are correct, could've done that as well. It was just easier to do the modification...

[@AhmedTheCoder]

can i raise voltage up to 30 volts

[@KerryWongBlog]

Unfortunately no, the maximum output voltage is typically limited by by the pulse transformer and in these ATX power supplies, the max you can go on these 12V rails is probably no more than 16 to 18V.

[@AhmedTheCoder]

i will make that in the same way you did , and thank you very much.

[@kantihaldar5403]

@@KerryWongBlog can i get -18_GND_+18 5A (180watt) for my amp

[@sizzlean9459]

Just Remember Mr. Wong...the Creator made you with a few components Dangling!

[@jacktheninja]

it's funny how i have the same PSU and the 12V rail is marked as 31A .

LOL. No overvoltage protection?

[@tjsin59]

i subbed , thanks for the info

[@KerryWongBlog]

Thanks!

[@juanabreu5127]

You have said nothing about changing output capacitors for higher voltage ratings; output voltage rails even if not used are going to be raised too.

[@KerryWongBlog]

Good point. In practice though, the output caps have quite a bit of margins. Most supplies I've seen use 25V caps for the 12V rail and similarly overspec'd for other supply rails as well.

[@AhmedTheCoder]

and nice work

[@ufothing]

he is pointing to a 1 point 5 k resistor above the 2 point 2 calling it 2 point 2 ,,,the 2 point 2 resistor is the one at bottom

[@rajurn8046]

Searching for this video 😭😭😭

[@b.lukito6063]

how to increase current output? 😁

[@pollydor07]

THANKS

[@OneBiOzZ]

that mains input IEC wiring looks rather dangerous (at least from the camera angle)

[@KerryWongBlog]

Yeah, it's not the camera angle I was surprised that there's no heatshrink on the connectors at all.

[@robertcartier5088]

Guys, expecting heat shrink tubing on connections that were never meant to see the light of day is a bit ridiculous, don't you think? If your PC gets banged up enough to have ANYTHING touching those connections during normal use then you have bigger problems than non-insulated connections! ;-)

[@OneBiOzZ]

well it looks like there is less than 2mm of a gap between wiring leads, one surge and you have a nice ionized path of destruction

[@robertcartier5088]

Alyx BioHaz And that is why fuses exist. You're kidding, right? How much of a surge is needed to create an ionizing path through 2mm of air? ...that was rhetorical. My point is that expecting a manufacturer of relatively cheap power supplies to guard against such an extreme situation is naive at best! The extra cost is not justified if the unit is not meant to be user serviceable.

[@OneBiOzZ]

It's before the fuse, 400v can easily jump 2mm, it won't trip the house breaker unless it's an rf breaker, and it's a short to ground... I may have only been in the power supply industry for 5 years but even I know that it's a recipe for disaster and I have had seen surge arc overs jump a much larger gap than 2 mm

[@jcgarcia4575]

Tl494 pin 4 connect with ps-on

[@fellpower]

What u didnt said is - an important thing.... If u had your ATX Power Supply to the mains - and open it after, the Capacitors are charged - with barely over 400V - that can KILL u !!! Plz, before taking out the PCB, discharge the Caps !!! Or u will never touch anything anymore....

[@iborschtsch]

Cracked solder joint detected.

[@LogicWheels]

First thing I noticed :)

[@andytipping70]

your 22.2K" RESISTOR LOOKS SUSPICIOUSLY LIKE A 1K5 TO ME?

[@electroman1556]

Its a 15k

[@LuLiMicMot]

Làm dỏm mà nói nhiều quá

[@cozzyinternet4706]

There is definitely something Wong about this..........

[@ufohunter3688]

Don't expect your batteries to last long. Li batteries need to be charged in proper and unique steps, using Pre-charge CC, CC and then CV and then shut-off at the right voltage.

[@KerryWongBlog]

Lifepo4 batteries are not picky about how they are charged. In fact, as long as the terminal voleave is correctly set and the charging current stays within the maximum allowed charging current everything should be fine. The only issue you might run into is slower charging time as the current tapers off much earlier than CC charging profile.

[@pollydor07]

Thanks