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!
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!
You are a very good teacher. Few years ago I had a hard time trying to understand how this type of power supply works. I think it is also called 'ringing choke converter'. Thank you very much.
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.
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.
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.
Thank you for all your hard work on this. When you started the tear down, you mentioned that although the P/S was labeled as being rated at 2A, it actually was only able to supply 0.5A. As you went through the tear down, I kept waiting for your conclusion to tell us what component(s) should probably have been changed, to make it a true 2A P/S. I'm not complaining at all, just saying. Anyway thanks for this and I liked how you explain the circuitry. Thumbs up!
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!
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...
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.
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!
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
6 ปีที่แล้ว
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
@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?
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
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
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?
Shunt the 10 ohm current sensor with another 10 ohms. I don't think that will improve the reliability of the circuit, though. Good luck, and check the transformer for smoke.
And use a faster transistor, like a FET. Then beefier wire and bigger core on the transformer. And a better output diode, and bigger cap on output. Outside of that, it's a fine circuit.
I use these PSUs on a daily basis and I'm very keen to have one that is safe to use. Can you recommend a good, safe PSU that is reasonably priced . Or what should I look for in a PSU that will tell me if it is good and safe ? Great work, btw.
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
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.
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.
DiodeGoneWild Thank you so much for the link. It was very useful. 😊 I think you should do a video reviewing this circuit, that you've already built. I'm a fan of your videos, especially the power supply videos. No one will go that deep on an explanation like you do. Keep going dude.👍
I have tried changing the input cap to 22uf 400v instead of 2.2uf, and change the output cap to 2200uf 25v but still the output current capability isn't improved. I think the transformer has to changed with a bigger one.
Hey, this is switching power supply, so if you do not want to replace the transformer try to play with the flux frequency in other word increase the switching frequency on the primary side. Supposing the transformer secondary wiring will not burn that should result the increase of the output power of the SMPS.
it seems a good one. I will try if changing some resistor and cap will do the trick. If it can withstand 1A for few seconds, then I will replace that shottkey diode as well to 3A
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.
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).
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?
Another great video, thanks. The psu is dangerous and not designed for 2 amps output. I would bin it ...maybe save the case. I have some power resistors for checking the current in power supplies and they are a quick way to test whether the unit is up to spec or indeed working.
Против Глобал how to tell if that a bit high priced psu is 100 times better than this just by looking at the advertisement? What clue should I look for?
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 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!
This is how engineering should be taught and not just giving theoretical info of the individual components. Great video 👍👍
Great video as always .Keep the good work sir .You are the best teacher .I have learned a lot from you 😁
Na mě udělalo opravdový dojem, jak jste bravurně odizoloval kabel kombinačkama. Respekt!
No jo, to jsou léta praxe :D
You are a very good teacher. Few years ago I had a hard time trying to understand how this type of power supply works. I think it is also called 'ringing choke converter'. Thank you very much.
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. 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!
i have one and opened it. there were cables that looked burned but not connted to anything.
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.
Why wouldn't show how to redo it to capability of real 2Amps?
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.
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.
you are a winner, best of the best !!
good insight. also Like the way how you opened the case its always a headache for me.
yaayyy a new video
Thank you for all your hard work on this. When you started the tear down, you mentioned that although the P/S was labeled as being rated at 2A, it actually was only able to supply 0.5A. As you went through the tear down, I kept waiting for your conclusion to tell us what component(s) should probably have been changed, to make it a true 2A P/S. I'm not complaining at all, just saying. Anyway thanks for this and I liked how you explain the circuitry. Thumbs up!
"The construction looks very Chinese"
-DGW 2017
👁️💧👄💧👁️
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.
Very good and clear explanation of how the circuit functions.
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!
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.
How about the complementary power amplifier? I want to learn it!
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?
I like the way you explain. Plain comical and just nice
I like the way you said "ARE YOU KIDDING GUYS? THAT'S RUBBISH!" its cool!
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...
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.
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
how many more of these power supply vids are you gonna do
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!
The best TH-camrs ever 👍👍👍
I bet replacing that 10 ohm sense resistor with one much lower, like 4.7 ohm, it would fix it
It would be great if you could do modification video to make this power supply works properly, or any other cheap electronics from china.
"This looks like a chinese board" 😂👍
I've never seen that type of pipe clamp before; what is its manufacturer?
Great video! Thanks. I almost but that thing. Do you have any recommendations where i can get a good DC adapter 12V 2Amps?
I have the same adapter for my mini tv, should I get rid of it?
Looks good! Where can I buy this adapter?
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
@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?
That's not a class Y capacitor. It's a class "why?" capacitor.
Olá, sou do Brasil e preciso de um adaptador igual a este com esta especificação. Como faço para comprar?
What's the sense of placing optocoupler if 1kV capacitor connects mains side and output?
i'm getting confused, according to schematic you draw, in transformer is going DC power.
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.
How to upgrade the power supply to 2A?
Is it possible to change the 2A to 5A with 12V?
How does one measuring the quiescent power?
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
How can i make this .5 amp to reach 2 amp any support to me will be well appreciated.
What is a switching adapter? If I have a ac120v/dc12 and a ac120v/dc12v switching adapter, can they be interchangeable?
What's the purpose of 2.2nF, 1Kv capacitor? Seems like providing AC ground reference for output AC ripple.
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
This was really one of the best presentation. I've seen 👍👍👍✌️
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?
Mr Diode, jak muzu udelat 1 mode driver from 5 mode driver. Thank you. Vlad
Excellent. Can you show a way to improve it and get to 2A?
Shunt the 10 ohm current sensor with another 10 ohms. I don't think that will improve the reliability of the circuit, though. Good luck, and check the transformer for smoke.
This slightly improve the current for couples of milliamps. The supply needs more optimization by increasing the switching frequency I suppose.
And use a faster transistor, like a FET. Then beefier wire and bigger core on the transformer. And a better output diode, and bigger cap on output. Outside of that, it's a fine circuit.
James Van Damme hehe.. i.e replace everything except the board😅
Can you do a project for build your own smps power suply using scrap from broken psu?
Is the emitter on the optocoupler directly connected to the base of the 2SC945 transistor ? Does it not have current limitation?
I use these PSUs on a daily basis and I'm very keen to have one that is safe to use. Can you recommend a good, safe PSU that is reasonably priced . Or what should I look for in a PSU that will tell me if it is good and safe ? Great work, btw.
And the autopsy of the transformer?
You sir are a total badass!
Great video!
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.
Sir please explain how this transformer works ...and what should be proper windings number for 5v..1 ampere transformer..smps
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
"the conclusion is.. it's rubbish." 😂😂😂
😂😂
in the adapter
when the green led lights steadily what does that mean ???
when the green led is kept flashing what does that mean?
Can you tell me smd ic Q2RD replacement oscillator ic of power supply xly-4200150 model 42volts
Awesome video very detailed look forward to seeing more👍👍
How to differentiate between an inductor and resistor in a circuit like this
Is an ac/dc adapter the same as a switching adapter?
So which 2 Amp 12V on Aliexpress should i buy.
I just bought two of this power supply...when I receive them I'll let you know is it the same...
Hello, what is that plug socket that you use to measure power? Can you show us how to make one? 😊
Hello, it's more or less this one:
danyk.cz/wmetr_en.html
with a second shunt added to get 2 ranges.
DiodeGoneWild Thank you so much for the link. It was very useful. 😊 I think you should do a video reviewing this circuit, that you've already built. I'm a fan of your videos, especially the power supply videos. No one will go that deep on an explanation like you do. Keep going dude.👍
I have tried changing the input cap to 22uf 400v instead of 2.2uf, and change the output cap to 2200uf 25v but still the output current capability isn't improved. I think the transformer has to changed with a bigger one.
Hey, this is switching power supply, so if you do not want to replace the transformer try to play with the flux frequency in other word increase the switching frequency on the primary side. Supposing the transformer secondary wiring will not burn that should result the increase of the output power of the SMPS.
Oh, and there is a diode at the secondary side which still has to deal with the increased current....haha
it seems a good one. I will try if changing some resistor and cap will do the trick.
If it can withstand 1A for few seconds, then I will replace that shottkey diode as well to 3A
Np ? turn
NS ? turn
aux(fadback) ? turn?
Very good explanation and analysis, thank you
Hi, how do determine how the transformer is wound to put the dots on the schematic?
I wanna know watt-meter circuit which shows power consumtion 0.14watt on 01:08.
Cheers from Indonesia
danyk.cz/index_en.html Look for wattmeter circuit here.
how do you test the amps or ma of a power supply?
He connected an amp meter in series with a big resistor.
please sir tell me how to connect yellow multimeter to get wattage
please you tell me number of useing transitor???
I just wish my high school science prof was good at explaining as you
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.
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).
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?
Hello,
Can you please help me with the circuit or youtube video for 12V 2A from 220+Volts ? How to approach that? Thank you :)
Another great video, thanks. The psu is dangerous and not designed for 2 amps output. I would bin it ...maybe save the case. I have some power resistors for checking the current in power supplies and they are a quick way to test whether the unit is up to spec or indeed working.
you have schemetic for adaptor epson L210 ?
How to repair the charger isn't the plugged in
would have like to see some waveforms at the diff stages...great video!
Nice video! Silly question: What is the 2,2nF 1kV capacitor for??? Why it's there????
It's there for interference suppression. This one reduces the high frequency noise at the output.
Thanks you very much! I have wondered this thing so long. Thanks again! :) Your videos are great.
DiodeGoneWild sir i beg to disagree. The cap is to reduce EMI to pass certifications on undesired emmissions. It has no effect on output noise.
How can I get the transformer which is used in the circuit???
Please help me if anyone can
thanks realy helpful .. where you buy this form aliexpres or another
It's from Ebay.
Против Глобал how to tell if that a bit high priced psu is 100 times better than this just by looking at the advertisement? What clue should I look for?
How does work axillary wending in smp tranformer
can u tell me what is the alternative of a 500uf 7.5v electrolytic capacitor. ? well i cant attached the image here to show u.
Lot of knowledge, very impressive...bravo !
neukázal by si nám nějaké tvoje výrobky/vynálezy ? Na tvých stránkách toho je dost, video by bylo supr (y)
If the zener diode is 11 volts. Why the source has 12 volt output?
Because the voltage drop of the optocoupler diode (about 1V) is adding to it.