Simple 12V 1A LED Power Supply - with schematic and transformer autopsy
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- Опубликовано: 26 авг 2024
- Today I took a look at a very cheap Chinese 12V 1A adapter from Ebay. The listing says it is for LED strips, CCTV, routers, audio/video equipment, etc. This AC/DC adapter has 100-240V universal mains input and 12V 1A DC output. I took a look at the board layout, reverse engineered the relatively simple schematic of it and made an autopsy of the transformer. This power supply is quite dodgy - there's no fuse, no EMI filter, no inrush resistor, no snubber network and a very questionable capacitor between the primary and secondary side. The isolation distance on the board is 1.5mm. I have seen more dangerous transformers, but also much safer ones. This switching power supply claims 1A current capability, but actually is capable of only 0.5A. The cable wires are quite thin. The plastic housing is very easy to open. This adapter can pose a risk of an electric shock or fire. I personally wouldn't use it.
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I’m loving re-watching these older videos of yours. There’s nothing decent to watch on RUclips lately, so I’m watching your videos again.
By the way, I still support you on Patreon, I stopped all my other Patreon subscriptions, just kept yours going because I love this channel.
Thank you for your support! I really appreciate it! I will do my best to keep making interesting videos ;)
I really like the explanations on how an smps is working, keep up the good work!
Thank you for sharing your knowledge and what I like the most is when you give the characteristics of the winding and details of the transformer.
Thank you very much
8:03 OMG I CAN'T RESIST ITS CUTENESS
so i should buy a resistor
just getting addicted to your testings & videos! great job mate!
i subscribed as soon as you start dissembling the transformer and then start determining the gauge of the wire. this was truly a reverse engendering video. nice job.
3:28 "even in a short circuit it doesn't give you one amp" LOL
The dog looks bored, electronics isn't his thing. At least the cat will play with the components. How many animals do you feed?
@Edward Damian It's a scam, don't fall for it. Hacking a multi million company from a website... please, don't fall for those
how to make that load tester? (schematic)
I cant send a schematic, but i think he has a NPN transistor and a potentiometer driwing the base of the transistor. It looks simple so try it *AN DONT USE IT ON TOO HIGH CURRENT AND WITHOUT HEATSINK.*
can you explain more how the power supply limited the current and why the voltage fell?
Yep, you sure are right! I bought one that looks just like that for a replacement power supply for an external HDD. It wouldn't power the HDD at all. Great tear down and explanation..Thank you.
So.. It is for charging your cat?
AC/DC= A Cat (to) Dog Converter
No, this is for 12V-cats. Czech cats usually run on 220V AC.
,it cracks me up when he stops after reading ADSL CATS 😂😂😂
i was gonna say that =]]
Cat charger? Cats are living creatures, and not electronic devices.
I saw one of your videos ... first I didn't like it at all !!!
But I tried to to watch another video and another. .... till i surprisingly loved it ... now subscribed to your amazing true channel. ...
Mohamed Asim I'm not alone. :)
I have the US plug version of this, and the plug came out of the casing and got stuck in the outlet! VERY unsafe!
Your channel is for me like a second college....
I learned many more electrical concepts...
Thanks...
Keep it up
Sir your channel is so good and i am learning so many things from your videos
I am so happy for sharing your knowledge
Thanks
The nice thing about it though is the blue LED is dim. Often, cheap electronics will include a blue power indicator LED which is super ultra bright, like blindingly bright. So bright, it's obnoxious.
I also have a recommendation for you ... test these with varying input voltage. The reason being, these simple PSUs sometimes are sensitive to input voltage, and so they can do even LESS current output at lower input voltages. (You have 240V I think, and it's rated for 100 to 240V... so try 120V or so)
I always put a piece of dark sticky tape or paper over it :).
Was just about say same at blue leds :)
What's better than your awesome accent? Your passion for knowledge and sharing it.
Thanks?
I like the effort for maximum simplicity of this one chadapter :D
Hi. Can you make a tutorial video on the tools you homemade ? Like this adjustable load circuit
My variable load is here:
danyk.cz/zatez_en.html
@@DiodeGoneWild q
Thank you very much for your videos so well developed, although not having mastered the English language, I have to use the translator and I miss many of your interesting comments, I would appreciate it if you could activate the subtitles in some way since it would be easier to follow it, Thank you so much for your excellent videos.
what is the model number of this ferrite transformer??
I think it's EE-13
Excellent Demonstration of SMPS power supply.it was step by step explanation of all components used in smps.nice to see explanation of transformer n it windings.thanks for video.
I would like to see you improving these kind of power supply like you did in one of your video
reeeesistor love the accent
Isn't that 2.2nF capacitor (visible in the schematic) ruining the isolation?
Mainly because it's isolation strengh is only a quarter of what's required (separation between mains and secundary should be 4 to 5 mm or kV - Y2 class capacitors fit that requirement but 1kV ones obviously don't.
@@mjouwbuis
Now, after reading your comment I calculated the impedance of a 2.2nF for 50Hz. It is quite high in fact; 1.5MOhms.
So, I guess what you are saying is that normally this impedance is so high for passing enough current through human body. The only danger might be that if the voltage rating of the capacitor is not enough, it might break and then pass some current to human body.
So, if we choose a high enough voltage rated one, it should be fine.
With 10 Ohm as current sense resistor the max peak primary current is say 650 mA (assuming the left transistor Vbe threshold to be 0.65V). To get 2A the current sense resistor has to be 0.6R (according to LTSpice).
In October, our Host did a review of a JCY-1220 (2A). Here we have a JCY-1210 (1A). The PCBs look strikingly similar.
the trasformer coil is made of aluminium thin wire, the residence is much higher than use coper wire one, thus cannot out higher range of current, and will get burn down easily.
i watched this video for to see your dog only 😀, where is you cat ?
😂😂
Yep i thought 500ma max, they bullshit so much :-(.
So could you have squeezed out a bit more by making the emitter resistor 8 ohms and the bulk voltage cap 3.3uf?
Do you ever get bored ripping psu's apart...... sorry daft question lol :-D
I also don't understand why do they multiply the current by at least two. The user just ends up with the conclusion that it doesn't work.
I think this si not worth any improvement... if you want to squeeze a bit more, just buy a better one :).
The next time I'm going to open a 24V 10A power supply which I hope is a forward, not a flyback as always :). I also have numerous LED lamps to open.
The 12V 10A 120W one was a flyback, but flybacks usually never go above 150W, so the 240W one is hopefully a forward or a halfbridge.
DiodeGoneWild
I have an old Dell supply I wish you could explain. It's one of the weirdest ones I've taken apart. With 2 separate transformers, and 4 other wound toroids I'm clueless about what is going on in there.
This design comes buried under a lot of silicone though. I probably spent 2 hours digging silicon out of this one, thinking I might figure out how it works, but I still have a lot to learn before I will really understand this type of design.
drive.google.com/file/d/182N-Jy30p-X1psBmsb-Wzew1q3vn6GOk/view?usp=drivesdk
I don't know if that is flyback or something else like you were talking about (thus why I posted here)
-Jake
Upcycle Electronics.
The first transformer by the power input looks like the power factor correction one, there should be a mosfet connected to it and possibly a stand alone chip.
zx8401ztv
Yeah I was thinking this might involve a PFC circuit but I quit goofing around with it after I had trouble finding a datasheet for either IC. The 16 pin is marked:
*DAP019D*
*DAY097*
*TXD12481*
The 8 pin is
*DAS05*
*AZ62518*
*TXD3101*
I couldn't find anything on those chips. They are SMT so I'm guessing they are the typical manufacturer's prefix/suffix parts number encryption or proprietary junk.
Your correct about the FET on the primary side/first transformer, it's a K15A60.
I was also confused about why they would have built this with 4 toroids. There are 2 common mode chokes on each side of the safety cap. Then there is another oddball toroid with one winding in series with the PFC transformer, with high voltage poly caps going to mains... because all those magnetics weren't enough and they needed to add a capacitive dropper supply ... that left my head spinning, it's just too much 4 me ;))
To top it off the secondary output has a T0-92 packaged trany(IC?) marked 33W3031 that is placed between the secondary output rails and is marked "ID" on the silkscreen next to an output wire that looks like a signal line. Of course "33W3031" doesn't link to anything either. I assume this must be some kind of silly identification signal BS to force people to buy an overpriced "Dell" branded replacement for a product they probably engineered to fail... The same as their criminally proprietary AC mains cord/plug.
(Thanks Dell! I'm ashamed to have grown up in the same country as this BS.)
A strange thing emerges from the autopsy at 8:05..
Hello , i saw your link with your variable load. Can you please tell me which mosfet did you use and which zener diode.
would you please share the diagram of your artiaficial load and the parts to build it? That looks very useful
It reminds me my school days where we were tought basics of vernier callipers...
I keep telling you guys Chinese current is always "Label Number x .5 ", example 1 ChiAmp= 1.00 (Label Number) x .5= .5 amps- see? It works every time.
lol.
but noted.
also true :D
DiodeGoneWild , could you make a video showing how to do schematic reverse engineering?? That would be great help !!! Thanks.
Good explanation about how SMPS works. Keep it up.
Nice review of this cheap switching power supply!
4:22 = Luxury models have the "FULL WAVE BRIDGE RECTIFIERRRRR"
DiodeGoneWild
So what is limiting the current to 0.5 Amps?
And what parts need to be beefed up to make it true 1A or 2A power supply?
From my experience, just using a larger input capacitor (4.7-10uF instead of 2.2uF) will give slightly more power. Raising output cap value to 470uF should help as well. But the transformer is likely too small, and the output diode should be a little larger.
how to make your dummy load circuit. pls share if you can
Where is the cat????
I left for 2 weeks, grandmother takes care of the cat :).
Can anyone please explain me the reason for why these chargers giving lower current than its rated value. Why they cannot give the exact value.
Perfect time to pull out the shock dog collar :) baaaaaaark lol joking.
5:49 ,,some very doddgy interference capacitor" 😂
Interesting video. Please make a video of how you make your variable disload. I want to know how you test charger ampere.
It was nice of you to measure the diameter of the wire used . I would also like to know the size of the transformer used.
3:59 they pinched the hell out of one of those mains wires, that seems super safe!
Exactly that I want to know , excellent job sirji
I love when you draw scheme of citcuit. 👍 and SUB
I had one of these in another casing (that claimed 2A). The transistor and a resistor exploded under 1-1.5 A usage.
My mom bought some christmas LED lights that came with exactly this power supply lol. But it blew up right after 5 minutes of use!! Luckily the LEDs were still alive and I had another, way better PSU.
I prefer this dog rather than the previous shown cats =P
8:03 i think thats a jack Russel
Sir amp depending on which components of SMPS
it seen like mostly 5V , 6V, 9V,12V they are using same transformer that one in your video look like EE13 . the only different is they change the zener diode to make higher output voltage?
Gracias por tu vídeo. Saludos desde Nicaragua!
cheers from triode gone wild , have you seen capacitor gone wild i cant seem to find him...
@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?
What is the inductance of transformer
Why do you need an 8kv capacitor for isolating 240v mains? I would have thought 1kv would be enough?
Always interesting videos
Hi.. Im from india and i regularly watch your video..
Keep it up good work
I was hoping you would test out the fuse with 240 Volts :-)
oh yes, test these printed fuses!
can i usethis transfoforme dircly convert 220 v ac to 15 v ac ? if possible please show i connect it.
How much is the acceptable voltage drop in a power supply under max rated load?
how could you increase the current supply with this one? could it be done simply?
Thank u a lot sir, I got compete idea of a ac adopted which is very cheaper, i think it is OK for LED striplites.
your dog was nice touch
keep moving
thx 4 all
Your dog are very nice!
please make video: how to make high current transformer from mot (microvawe oven transformer)
Transformator 220V There a lot of videos like this.
i know, i want from diode gone wild
i dont know
Guys. Anyone can give me clue. I have tv power supply. Replaced pwm ic. Then connected power supply via light bulb. standby power 5 v ok but when power on , 60w light bulb slowly glow 5%. If led panel on light glow 100% and power shutdown. Can’t find fault. ? Pls help thanks.
please tel me how can builde like you varible load tester as show in your video
I buy these type of adapters from flea market like 0.25$ and they work every time.
They work, but with a lot of EMI, some risk of fire and shock and with only 50% of the claimed current capability :)
In my opinion, most of these are terrible products. They won't deliver nearly the amount of power they're supposed to. It's like a 4 wheel car with 3 wheels. You can drive it but have to be careful how you load it and use it haha.
Awww luv dogs I have 2 a chichua and a corgie. Iam so glad I found You..
How to know the value of the input fuse please ?
Příjímáš podporu ve formě nefungujících nabíječek? :D Mám tu nefunkční čínskou QC nabíječku...
Maybe I missed in the past: can you publish the shematics of your variable load. Thx!
It's this:
danyk.cz/zatez_en.html
The zener can also be replaced by 2 or 3 LEDs in series.
Thx! Fast reply as a Musk's rocket!
Good teacher😊
Do you have video on how to convert it into 5 amps output?
Who here thinks that DiodeGoneWild would make an excellent vampire in a Hollywood movie?
Hiho
I byed exactly this pn ebay - after 1week it makes puff and the house citcutbreaker falls down.
good day sir! can u tell me how to increase the current & the voltage output... even your accent is different but i can understand u very well the way u explain.
Hi
How to calculate auxiliary winding
How I can make load tester for smps. ?
Perfect analysis
sir please make a video on fence circuit of 3000 volts working methods. thank you.
thanks alot
the zener 12volt is true?
i think it must be 13volt or bigger
Ahoj. Neměl bys schéma té regulovatelné zátěže?
What is this circuit called, flyback or what?
How do you made the power supply tester?
4:21
I WANT THIS ON T-SHIRT !
please send explain theyour diy electronic load that show in this clip
Could it be another video about cfl light bulb?
You made many videos on SMPS now please can you make videos on something new & interesting i am waiting for your new video
Sir,mere pass 3wire primary side and 3wire secondary side me hai ,me I/p and o/p kese connection karu, please bataiye
What do you think of the amazon Basic cable?
If there are 180 turns on primary an 13 turns on secondary, there should be (13 / 180) x 230 V = 17 V on the secondary. How that 16 V capacitor is doing right there?
Focus on optacopler
The input high voltage 2u2 storage cap is too little (over 20V ripple, seen also at the output as 0.3V ripple). For 2 A this cap has to be at least 47uF
The switching power supply is regulated. Input ripple doesn't mean output ripple, unless the input voltage is so low that it comes out of regulation.