12V 2A LED Power Supply test - with schematic
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- Опубликовано: 1 окт 2024
- In this video I test a Chinese 12V "2A" switching power supply designed for LEDs, CCTV, routers, etc. It cost me only $ 1.80 including shipping. The actual current capability is about 0.5A and the safety is quite questionable. It's a classic 2-transistor switching power supply with an optocoupler, but it's quite underrated, has poor mains isolation and misses basic safety features like a fuse. It may be dangerous and it can only supply 1/4 of its rated current.
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Great teardown and analysis! I really appreciate your videos because you not only break things like this open, you take the time to reverse engineer them, actually draw a schematic AND explain it. That's quite impressive. You are helping more people than you realize. Thank you for making your videos!
Thanks, I will keep making such videos :).
Great video as always .Keep the good work sir .You are the best teacher .I have learned a lot from you 😁
"The construction looks very Chinese"
-DGW 2017
👁️💧👄💧👁️
"This looks like a chinese board" 😂👍
"the conclusion is.. it's rubbish." 😂😂😂
😂😂
The diode in the secondary is only rated at 1 amp, that's a clue.
Exactly. Because it only rectifies half of the wave the maximum continous output of the power supply is half of its rated amperage.
I like your accent. Hilarious
WHICH IS?
That's not a class Y capacitor. It's a class "why?" capacitor.
Why wouldn't show how to redo it to capability of real 2Amps?
Very good video tutorial, the problem is that my English is very bad and I would ask you please to activate the subtitles to be able to see it written in English or translate it into my language, which is Spanish. Many thanks. a greeting
a lot of Chinese products are rubis
you are a winner, best of the best !!
king of reverse engineering and schematic
i have one and opened it. there were cables that looked burned but not connted to anything.
I've used a similar transformer to make a 40W flyback. It worked, but took a lot of optimization. It goes to show 24W is possible, but the designer hasn't seemed to realise that!
NNNI
Yes, the trick is to go up in frequency. The amount of energy you can store in the core times the frequency is the power.
If you are making stuff for a narrow mains voltage range, it is even easier.
I bet replacing that 10 ohm sense resistor with one much lower, like 4.7 ohm, it would fix it
A great video! A good one. I just purchased two of these and I really need 2 Amps. They are currently in transit to me.
good insight. also Like the way how you opened the case its always a headache for me.
Thanks for the video, Dan. I had a similar power supply and I could not understand why my photo frame didn’t work. Checking your video and trying to prove the same on my power supply I found that at 10ohms resistor my voltage was only 2.8V, at 5ohms it turned off, at 20ohms my resistors went smoke :) I used 1/4W resistors which are probably too small wattage for this setup.
*left eye twitches*
The words "cheap" and "power supply" shouldn't be used in the same sentence...
Great stuff.. you are super entertaining too..
Great breakdown and analysis.
Your intelligence and insight are greatly appreciated.
The way you elongate the syllables on some of the words adds to the general air of wit and sarcasm as you gradually break down the 2 Ampère myth of this device.
Keep up the good work!
Na mě udělalo opravdový dojem, jak jste bravurně odizoloval kabel kombinačkama. Respekt!
No jo, to jsou léta praxe :D
You sir are a total badass!
Great video!
It would be great if you could do modification video to make this power supply works properly, or any other cheap electronics from china.
Np ? turn
NS ? turn
aux(fadback) ? turn?
How can i make this .5 amp to reach 2 amp any support to me will be well appreciated.
Hi, I really like how you describe the circuit operation in these type of videos. It might be nice if you could also show actual waveforms on a scope at the various points as you describe how the circuit operates. Cheers!
It can set you on fire? Cool!
Where can I get one for my ex-girlfriend?
There's this super popular power supply board in China, XK-2412DC. Would you like to get your hands on it perhaps?
Yes, I definitely would :).
Using this XK-2412DC supply: coudl I increase the voltage to 14,4 v???
Yeah Diode, how do we arrange it? Do we sponsor you the purchase price, do we drop ship it to you, or do you just get one on your own?
Siana Gearz ask him for his address with pm and drop ship as gif for him :-)
If you don't mind drop shipping it to me, I definitely won't refuse :). give me your email so I can send you my address.
Something is wrong with "Diodegonewild".His czech accent is not natural.I assume that Danyk has been abroad-may be in an english speaking country?
Even without such analysis it's obvious that little box can't deliver 12V @ 2A. High wattage power supplies are packaged like laptop power supplies (a larger box and with a separate AC cord).
Your musical speaking is unique 😜🤣🤣🤣
Yes
This was really one of the best presentation. I've seen 👍👍👍✌️
Olá, sou do Brasil e preciso de um adaptador igual a este com esta especificação. Como faço para comprar?
Have you seen such ‘Xing Ling’ SMPS modernized, using 1 MOSFET SSS2N60 + 2 auxiliary BJTs? In case you saw, or made a video, could you please share the link?
Thank you
And have a blessed Holiday season!
Not all of chinese product are bad. But the cheap one and the copy of some product with some fake societies. If you want something good get it from its original manufacturies it can be a little expensive but it deserve that price.
You are awesome..
Can you tell me smd ic Q2RD replacement oscillator ic of power supply xly-4200150 model 42volts
It's very simple: With surge of power hungry electronics, power supplies should be more powerful. Chinese give no crap about the power, they just changed lettering on the sticker. Easy hack.
Is it expensive to upgrade this ps to 2A? Perhaps next time you can come up with some theoritical diagram which part to replace so it can be used as its claimed power...thanks always...from your biggest fan in the Philippines - Dennis
Buy a PSU from a good company, it is cheaper and safer.
it's not expensive at all ,you must replace first capacitor up to 10 microfarads ,10 ohms resistor with 2.2ohms 1w and final diode with some 3A fast diode and everithing is OK
At 6:26
The main transistor generally stays on until the 40 Ohms in the emitter has enough drop to turn on the other transistor. The 10nF should be big enough that this happens before the capacitor charges too far.
The input side capacitor need not be big if the output side one is fairly large. Nobody is going to notice a bit of ripple in the output if the amplitude is smallish.
If I was going to use something like this, I would add a fusible resistor on the mains input to restrict the inrush and protect against shorts.
thank you, sir. I will throw it away to prevent danger. Why must people make and sell dangerous garbage, and how can I buy a safe product?
The construction looks really Chinese... 🤣🤣🤣🤣
Sir, today I have made this circuit by looking at this diagram, but no voltage is coming out at the output, please tell me what could be the reason.
I bought yesterday jcy-1220 12v 2A adapter , only 600mA output :)
Awesome video very detailed look forward to seeing more👍👍
i'm getting confused, according to schematic you draw, in transformer is going DC power.
(I am a bit late) conclusion these cheap only transistor psu's are rubish they cant handle 2 or even 1 amps total rubish but yeah its chinese "goodness"
voltedż regulejszon
I was just looking at a large number of 6v 2A adapters on ebay, and they all looked like that one for the most part. Most curious, the photos of every one had the output specs printed on it blurred or blanked out.
Thank you for the warning. That's why I came here.
I think you did a re run of this , but interesting to watch both old and new video of PSU , dog hilariouso in second
hi i knew right away that you are a neighbor from cz, otherwise a good explanation :D
Estamos en México traducir al ESPAÑOL
I like the way you said "ARE YOU KIDDING GUYS? THAT'S RUBBISH!" its cool!
yaayyy a new video
What's the purpose of 2.2nF, 1Kv capacitor? Seems like providing AC ground reference for output AC ripple.
There's a cheap Chinese power supply, usually 12/24 volts DC 15, 20 or 30 amps, and they usually claim 360 watts. They're very generic, would you be able to get your hands on one?
فاقد الشيئ لايعطيه
I actually have a bunch of those "2A" 12V PSUs. Now I want to put them under load and test them. Surely there must be some crappers among them?
How about the complementary power amplifier? I want to learn it!
Thank you. You just saved me from frying up a valuable piece of electronics, had it not been for this video, it would have costed me $30 to replace!
Pls, is it possible to achieve upto 10A using methods?
Why you need almost 10 minutes to conclude that is rubbish?
And the autopsy of the transformer?
Are you kidding me guys , is sooooo beautiful 😂😂😂🎉❤❤
I just got 1 12v 3a looks exactly the same and if I check voltage and amp it gives 12.4v and 2.5a. It wont power my monitor just flikkers a bit. Probably the voltage drops down while delivering some juice. :(
(dont buy this item yall not safe and doesnt function like it should.)
oh... this one blew up for me
A similar adapter blew the cover off at my place a few years ago, like the main transistor wet short circuit and desoldered itself because of such heat, luckily in a concrete basement room with no combustibles in reach, it blew the 16A fuse on the socket circuit and annoyingly switched the freezer on same circuit off, this adapter is really dangerous it is a fire hazard. I may add, I didn't overload it, it ran a latching relay circuit with 2 float switches for switching a pump, apparently the aquarium pump on 220v emitted a voltage spike that blew up the adapter, but it is really rubbish, shame that this is sold on Ali and Ebay with probably fake safety approval and fake CE mark.
Many idiots never understand cheap product goes to cheap consumers. You can design and make one with your expectations and see how much it cost.
What if you replaced the 10 ohm shunt with a smaller value resistor?
Would it try to supply the 2A and then set the transistor or transformer on fire?
Maybe we can "improve" the design :D
Did you change your colour?
I thought of that and put 2 ohm resistor instead of 10 ohm and change the output shottkey diode to 3A one. That seem slightly improve the current to about 650mA without significant drop. So I went all the way and remove the resistor and put jumper wire across. The result is BOOM, burned both transistor.
The conclusion I think we need to increase switching frequency, so it can handle the extra current efficiently.
😍😍😍
Like it, thanks for sharing :)
I have the same adapter for my mini tv, should I get rid of it?
@DiodeGonewild, i have made all circuit as you mentioned in above video. At no load, there is fixed 12V. But when i am applying load ( 12 Volt relay), transistor 13003 heats up and burning within 5 seconds. I have replaced three transistors. Can you help me in this regard that why it is happening?
The transformer should be in principle capable to transfer 24 W. But I guess the switching frequency is too low for this. In general I don't like the flyback smps. I don't understand why the people don't use double acting forward converters. They are also very easy to design and to calculate. And the voltages at the mains power supplies are stable enough.
Super..said.true.true...alll chinease electrical product has no safety features...atleast they shd put fuse.
hai good mornig sir this video nice but i need some clarity .draw the syhematric daigram and explain how to change 240 v to 12v or 6v or 5 v ....... like that what ever we requrired output dc voltage
My adapter got blasted when I turned on wifi. Please tell me what to do..?. Will my wifi work.? Do I have to change my wifi
Lol instead of buying this junk u could make ur own 12v 2a power supply by a safe transformer,fuse,bridge rectified,capacitor
What is a switching adapter? If I have a ac120v/dc12 and a ac120v/dc12v switching adapter, can they be interchangeable?
Great video! Thanks. I almost but that thing. Do you have any recommendations where i can get a good DC adapter 12V 2Amps?
Is it possible to change the 2A to 5A with 12V?
How does one measuring the quiescent power?
just like their cars nothing is made to last more than a year if that.
Looks good! Where can I buy this adapter?
Hard to understand speak English
I WANT THOSE PLIERS !..
Very good explanation, I understand so much. Good job!! Thank!!
Just yesterday i tried to switch on my ceiling led lamp (with intensity regulation and ir remote). Accidentally i didn't flip the switch all the way. The lamp flickered and now it is deat, transformer buzzes but there is no output. Would you be so king and help me with repair?
vzdy sa pousmejem ked zbadam u niekoho na videu komunisticke kombinacky a tu je to komplet kombinacky, kladivo, klieste, hasak... inak dabre video ako vzdy (konecne vsetkemu rozumiem kedze nemas prizvuk :D )
I've never seen that type of pipe clamp before; what is its manufacturer?
How to upgrade the power supply to 2A?
balak ko sana irepair ganyan ko kaso naalala ko bagsak nga pala ako sa math 🙂
Zajímalo by mě, jaké výstupní napětí zdroj skutečně dává při zatížení. Předpokládal bych, že takový pokles je do značné míry způsoben extrémně tenkými a dlouhými dráty od výstupu.
KUBA64
Super crappy unit. Your closing scene should include you dropping it into a garbage can. Thanks for the video!
This is a charger circuit.
nice vid. it is posible to modify that circuit in order to make it safer? can you do a video about that? or maybe can you do a project of making a 12v 2A smps PSU using parts of an old PC PSU? Thanks
As a follow up why not to improve this PS by correcting it?
Adding protection and for example changing the current sensing resistor and increasing the switching frequency...
that would be very interesting and a way to learn how to give some use to this rubish...
What's the sense of placing optocoupler if 1kV capacitor connects mains side and output?