12V 5A Switching Transformer Autopsy - How it's constructed? Is it safe?
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- Опубликовано: 10 дек 2017
- Today I made an autopsy of the switching transformer from the 12V 5A power supply I was testing in the last video. So let's take a look how this ferrite core SMPS transformer is constructed and how safe it is.
The teardown of the 12V 5A switching power supply:
• 12V 5A LED switching p...
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Some of the practical things that you do @DiodeGoneWild sir is incredible. I love watching you work because I learn a new "trick" just about ever time. lol
This is the best non-segmented core transformer of this size I've seen. Thank you for spending your time to put out such great stuff.
I feel something missing and I click this video immediately.
Now I'm okay, thank you for your support!
Nice stuff, good to see a safe PSU from China! Also liked how you salvaged the LED at the end :D
Great job bro as usual!
:D...Entertaining and educational at the same time. Much appreciated!
I have been trying to troubleshoot an AC adapter for a laptop with a power of 330W , and thanks to you, I'm making progress step by step . The problem I encounter is the identification of the Coil of the active PFC. This one has a secondary winding which is on one side connected to the ground of the 2 MOSFETs of the PFC (they are in parallel) but I cannot find where the other side is connected. I told myself that it must be connected to an integrated circuit to detect a current crossing at zero (ZCD) but none of the legs of the 2 closest ICs correspond (the other ICs are on the 19.5V side (An OP2990 and a TEA 1995 ).In addition, these ICs are unreadable.The other problem is the identification of the primary of the output transformer.I followed the tracks with the ohmmeter and the inductancemeter but my diagram is not consistent with an LLC assembly The choke which is between the 2 MOSFETs has several connections (which I don't understand) and is surmounted by a radiator (which I understand) I am not looking for the values (x milliHenry, etc.) of these materials but their installation and wiring I wrote to the company DELTA from whom I bought 5 of these power supplies but m, despite my reminders, they do not even have the decency to answer me.
Do you know where I can find this information. Thank you in advance
Sir huge respect to you ..🙏 you give great knowledge to us
Thnks for your videos. It would be amazing if you could show the core gap and measure the inductance of the primary before taking it apart. Keep up the good work
Excellent Operation !!!!!!!
Hi! Could you please do a video on switch mode transformers and their windings/pin layout please. I'm new to electronics and learn so much from your videos. One thing I'm struggling with is the inputs and outputs of transformers, where the windings are connected to the same pins like they were in this one...(auxiliary and secondary). Plus some transformers have 2 pins, some have 12!!! I'm sure it's simple, but the way you explain things is so brilliant that I know I'd leave the video no longer confused.
Hiii! I really like your videos!
muy bien doc. quisiera saber qué número es el IC oacilador, espero de su respuesta gracias... saludos
Very nice! I always thought trying to recycle these transformers would be useless. But now I know there's a way of opening them withouth breaking the core. Thanks.
put one of those ferrite side on the long rod of soldring iron for 30 secs it works too
@@dunderdee so you let thermal expansion do the trick?
Great video
I've taken apart transformers that used wax to pot them. I've also had few high frequency types that just came apart easily after removing the tape. I thought some of them must be epoxied. Thanks for getting me to try boiling. Does this work for I/E types as well? Every time I've tried to separate an I/E core I've managed to bend and ruin something. I've yet to get motivated enough to put a blade on my chop saw and break out the welder...yet.
It seems to work for almost any ferrite transformer :).
But how much windings should I do if i want to use it in 24V SMPS?
Can U do a concise video on the design of a flyback transformer, just like the one you disassembled in this video
when boiling the transformer how long should I let the transformer boils?
Please there is no output from my high frequency inverter and one side of my mosfet always get please what could be the problem
What will happen when i will not make space for the ferrite it will work or not?
Hello sir sir i have rewind one chopper but it heat fet 20n60 and the chopper out current ok when i connected to batry its heated ic uc3843 and burn also fet
Good video done well
Why was the secondary winding sandwiched between primary winding? Why not to put Primary winding first and then the secondary winding or vice versa?
I had longer not fat 2.5 sm or 3 per 5 or 6 long transformer today i got pissed i used my jet lighter to heat up one of the sides sucsesfually remove half of it and just pulled the other one after seccond heat up on it cause i miss to see that some dump put silicone on it :/
how this transformer works? With four primary and two secondary?
Sir ... Make a video how to modified ATX PSU (TL494) to audio Power Supply (centre tap) big Voltage & Ampere
this is close what you ask for. ruclips.net/video/_CELYqo7KfQ/видео.html
where is the next video ??
did you done 5amp on output by this supply which was 3.6amp ????
actually i got the same power supply as in in your hands (same model) and i also have the same problem its Not giving 5amp on the output, over current protection actives around 3.7amp, if you did converted this supply to 5amp so plz share me how i can do this with my one, which is same model as yours
i have the feeling that the ratio 36/6 is a bit off and they should have winded about 46 tuns on primary (that would increase the primary inductance and lower peak primary current that now hits peaks and triggers IC current limiter early) and 6 on secondary and no other change...Chinese economy to primary coil and rely on regulation to do all the job???
👍👍👍thanks for the boiling water tip.😀
Never thought that boiling ferrite transformers in water would release the glue so easily. I normally put them in a solvent for a couple of weeks and then disassemble them. Tried the oven once but had bad results and went to the solvent. I'm going to try the boiling water, but I don't have an electrocuting heater - I think the shock from the mains helped make the thing shiver and crumble :-)
didn't wok for me, pobably work bette for these chinese transfomers but mine was from a sony stereo and it used that white glue cement or something
Some transformer use some high resistance glue, in this case you can use a hot hair gun, take precautions if you use a hot air gun, the surroundings can be very hot a and use gloves when you try to dissamble the hot core
Is there an explanation regarding for why as increasing frequency would give more power for a switching mode power supply
@@liam3284
Thank you for your answer.
good job
How do you determine primary and secondary,Auxiliary winding??
On step down transformers (which are the vast majority) primary would be of thinner wire and many times more windings. Auxiliary typically would have the LEAST windings, for they are low voltage used to start oscillation IC to get output started. Usually, the inner winding is the primary and the secondary is wound over the primary. On larger transformers, simple resistance test would reveal the pairs. Primary would have higher resistance.
Ahh boil them, i wondered how to take them apart without breaking.:-D
Do you think you could make a better supply for 12v 5 amps?, just wondering :-).
Is the sheild to stop capacitive connection or some odd frequency effect?
I don't get why capacitive coupling would need to be suppressed. I mean chances are there is a Y capacitor from primary to secondary externally anyway. Oh but that one is tiny enough not to act as an effective antenna... mhm.
I was asking a question, i don't know what it is there for, a faraday sheild of some sort??.
I don't make transformers so i havnt a clue :-).
Yeah well i'm just trying to think along, and i too am puzzled by this.
Boiling works well :). Hot air gun may work as well, but there's a chance of cracking the core because it doesn't heat up so slowly and evenly. The heat gun may also melt the plastic or sticky tape, because in hot air, thin objects will heat up much faster. ... The shield is there to stop capacitive coupling. Otherwise at the output you may have a high frequency voltage referenced to ground.
You're right, a Y1 capacitor is usually enough. And sometimes the maker doesn't care at all :).
V good Sir vedio Thank you very much
What device do you connect to the network to boil water and dismantle ferrite? Like video !!
This is some chinese stuff. Historically it was done with two razor blades tied with a string around a piece of insulation. Hard paper or wood or something. And connected directly to the mains voltage. But it isn't really a good idea...
I need a video just about your awesome SMD soldering iron that you got there.
That thing is awesome. I started with a huge, Weller, pistol grip soldering iron in the automotive trade, still have it 35+ years later, and it's still a BEAST.
You know what, I've never tried them. I've nearly bought one, but the tips look way too bulky for close work and the guns are pretty bulky in comparison to the standard looking ones. Are they really that good?
Cool !!
Hey! Long time ago you did teardown of those Alocacoc Power Cubes and you said thay you want do the same for the remote control (button), because they are saying it's working wirelessly without battery. Any news that you will do it? Thanks!
There's a chance I will get the remote for Christmas :). Then I will make a teardown of it ;).
Thank you!
Thankyou
Nice
What solution solution use
Diode the only thing more that you could have done is noted the gauge of the wire. If you do strip a transformer again it would be nice if you can include that information.
I can't recall where did I put my tool to measure the gauge :). I keep samples of the wire and I will measure it when I find the tool ;).
Thanks. Always good to see how close to the wire limit the Chinese went.
What is the name of this core shape?
Amazing! :) Boiling, never thought about it. Brilliant idea.
I tried to build a transformer on a small toroid. I used phone cable(ones solid wires). I wanted to have 2:1 (ex. 220:110 , 110:55)
Did 20 turns on one side and 10 on the other, when I tested it on 110 v(actually 130) , it burned/melted and sparked :'[
Poof, plugged it out. Dunno what went on! Or why! I figured since it was like 1 Ohm in resistance, it was like heater probably dealing with 130 amps or at least as much as that outlet was able to push, could be 10~20 Amps!
The 1 ohm or so resistance in itself could have been good, if the inductance at 50 Hz were high enough. If the core is a very big one. The problem was that 20 turns wasn't enough for that core for that voltage, and the current saturated it and became a resistor.
To use an unknown core, I use the following method. Wind a known number of turns (10..100, depends on core size), then assemble the transformer. It's a little tedious for an EI laminated core, but it should be properly built for this test. Connect it to a variable AC voltage source. Variac is the easiest, but if you don't have one, a fixed transformer with a bunch of series resistors, or a wire-wound power potentiometer will do.
Connect a series current meter and a voltage meter to the transformer under test.
Set a low voltage, then write down the current. Increase the voltage, then register the current. Draw it on a graph. You will see a linear portion, where the current increases proportionally as you increase the voltage. Then there will be a point (more like a transition zone) after which the current will increase way steeper than before. That point is where the magnetic material starts to saturate, and increasing the current further just causes dissipation in the winding due to it's resistance, but it wouldn't induce any more current on a secondary winding (if it were one). Practically this is the point where the inductor starts to trasition to a wire-wound resistor instead.
Choose some point below or close to the saturation point, and read the measured voltage from the graph. Divide the number of test turns you wound with this voltage.
The result will be the number of turns required for 1V. Do not round it to integer values here.
From this point on, you should calculate how many turns you'll need for the required primary/secondary voltages, and decide whether will it fit on the bobbin in the first place or not.
For this, you have to be decide on the wire diameter first, which is a different story (thermal design quoestion), but you should not calculate with 100% fill, because it certainly would not fit in practice because of the terminations, isolation, uneven winding and such. 70-80% is a good starting point. Then if you want more exact secondary voltages under load, you should add some percent to the calculated theoretical turns of the secondary to compensate for the losses. This depends on the size of the core, the coupling, and the thickness of the wire. Good starting point is 5-10%, but might need some experimentation. Wind the primary first, then you can replace the secondary on top of it with way less work, in case you miscalculated it.
I guess you’d could call the LED cyan as opposed blue as this seems to be the latest fashion on LED colors....
one, tyu, three,...., twenty tyu,.....
nice blue led
Thanks for this informative video! I like when you examine things down to the ground!
Its a pity the Chineese exaggerate all the specs as they like. You never know what you get! The only thing youl could be quite sure about is they dont stick to their specs at all!
Most interesting is the light of little torches powered by just one liion cell and they claim you can get 6000 lumen or even more :-). But they also sell liion cells in 16850 format with 10000 and more mAh - as well - so it might work ;-)
They can claim crazy numbers because most people have no idea about physics and electronics. No more than 3500mAh is actually possible in 18650 size. The 10 000 mAh cells actually are 500mAh. The lumens are usualy multiplied by 10. The world's best LED efficiency is about 160lm/w. You can do a simple math: A 1W LED can't be oved 160 lm. Cheap LEDs are even less efficient (100lm/w or less).
Yes, you are absolutely right! I am also an electronic hobbiest and know about most of the real specs :-) In some times its obvious they are exaggerating but in some cases its not. I bought a DC buck converter which is rated for 40V input, 1.2 - 36 v output at up to 9 amps. The specs of the switching ic is only 8 amps max, but needs extra cooling. The bad thing they also used an 78L05 voltage regulator that is only rating for 30V max input, so its far over the specs already. But you can only find out when you examine the products deep down to the ground - like you do it :-)
saudações do Brasil + like. interessante. pra soltar essa cola eu uso água gelada (com cristais de gelo) e a seguir mergulho em água morna. sucesso.
next time -- when you are going to investigate safety: The most important test you can make is a high voltage test between primary and secondary windings. This test shows if the insulation is sufficient between the 230V primary and the low voltage secondary...
The importance of the extra insulation is to protect you in the event one layer is compromised. They would all handle a 240v test or they would burn up as soon as they were turned on.
is their an air gap in the core ??
Yes, there is. It has to be, because it's a flyback.
Ah - one more - just a suggestion: could you make a video how to connect 2 or more switch mode power supplies in parallel for more output? I know its not suggested because of uneven load effect or worse reverse voltage into the weaker supply. I would also like to see if its possible to control multiple SMPSs in parallel with CV and CC-regulation (constant voltage / constant current). There are cheap chinese SMPS that deliver up to 40 V at 5-8 Amps for little more than 3 USD. If you could connect them in parallel it would be nice to built up a real powerful bench supply :-)
3 bucks? no way
Why not? Give it a try... Maybe you have to balance the output via some small resistors / shunts but the cc will prevent each of overcurrent - wont it?
I was doubting the possibility of being able to make a 200W+ SMPS for that price
You have to use 2 exactly same power supplies. Measure and set same voltage before connecting the load. Also it is preffered to use sepparate wires from each power supply and connect + to + and - to - right before connecting to load.
Хорошее видео
Adam o kadar bobin açtı ki aklı led'e gitti :D :D :D
Kafa kalmadı adamda :D
Aynen:D
I like your accent, don't change it. Please show us how to make safer transformer. Thank you
👍
I used to heat them with a steel sheet on a gas stove. I never thought 100°C would be enough to soften the potting.
It's usually just glued with normal superglue in the cheap power supplyes.
Can you take it again to live? You can do challange ;)
You are best 2000000 times
Hahahahahahaha tracked the same wire i was like hmmmm can that go deep there o.O @_@
can still be used the hot water for coffee😁
RE MAKE TRANS PLS :d
I can hear clock
So do I :). Several clocks actually...
please make video of chinese bluetooth speaker :)
preco nepouzivas "vecne hroty", tieto rucne robene hroty dlho nevydrzia a zle drzia cin a ked ich poriadne pocinujes. trafopajku som nepouzil od 1995teho. pouzivam vyhradne mikropajku, je 1000x lepsia
Nice video 👌 /#amyindia👍
it can only supply 3A, so don't put 5A in the video title.
despite that it is a good 12V 3A power supply!
hahahahaha is that for anyone who like to thear electronics see nice led be like ill replace that xD
Correction: That transformer was safe, 😬 RIP
You seems to be running after "power supplies" nothing else exist in your knowledge! !!
What will happen when i will not make space for the ferrite it will work or not?