DGW, you have done well I have another explanation on how the auxiliary winding works 1.After primary coil induces volt and current in the auxiliary coil 2.The auxiliary coil supplies the base of transistor through timing/frequency capacitor(1nF) and resistor(330ohms), turning transistor on fully 3. The timing capacitor stops conducting when fully charged thereby stop supplying the base of transistor. And setting frequency of oscillation 4. Then, the transistor is relatively switch off, 5.There is virtually no voltage or current in the auxiliary winding again 6. The timing capacitor discharges from its positive charged terminal through the auxiliary winding, electrolytic capacitor, resistor and zener diode to the timing capacitor(negative charged terminal) 7.As timing capacitor discharges, the reactance in the auxiliary winding is discharged through electrolytic capacitor/resistor and diode(IN4148). It is similar to protecting relay coil and circuit with diode 8.The zener diode also senses the voltage in the auxiliary coil. Once it exceeds zener voltage(~6.2volts) Zener diode starts to conduct and shorts the base of the transistor to ground.The transistor stops conducting and voltage falls and regulated. The transistor starts to conduct again when the voltage is lower than zener voltage 9. Since secondary winding has equal no. of turns as auxiliary winding, similar voltage of ~6.2volts is induced in it by primary winding. Zener diode regulates auxiliary winding voltage and by extension the voltage of secondary winding because of similar number of turns of the coils 10. If zener diode is replaced with one of higer value e.g 12volts. Secondary voltage would also be 12 volt. If the number of turns in the secondary is increased e.g to 24 turns. Secondary voltage would increase to ~11 volts, all things being equal
Sir i want to congratulate you for an excellent educational detailed and informative video. It was so detailed and precise the review and internal transformer demonstration that you did, that i managed to simulate the design of this switching supply on LTSPICE and it worked as exactly in real life inside a computer. So i decided to construct this power supply on breadboard. I wired a small EE16 transformer (taken from a 25w economy bulb ballast that all people recycle) by hand with the exact turns you measured.Reduced the internal air gap to 0.1mm to keep my core away of saturation. And it worked, even better than the factory made of the video, float voltage 6V, maximum output power 4.95V 0.55A(maby because i used 1N5819 diode instead of1N4148)! What i saw on the simulation is the low tendency for ringing spikes of this very very weird but simple topology. There is a probably a reason that the chinese didn't use (for economy of parts of course) a spike suppression snubber RC circuit that is present on all flyback topologies i have seen. The maximum spike on low load was 400V (european 220V AC IN) way way below the 600V rated voltage of 13001 transistor. Very interesting topology that works in a so balanced but precise way that i didnt find a way to make it operate on another output voltage. No matter what zener you used, or what turns ratio you used for the transformer, the smps wasnt regulating correctly and lucked power and stability. For a weird reason though it works perfectly when you use a 6 or 6.2 zener for a 5 to 5.5 output voltage.
I got the same 5V 0.5A power supply with same case but the inside is much better construction, and at 1A it still supply 4.5V! It has proper class Y1 capacitor, optocoupler, chip integrating the switching transistor, snubber metwork, good-looking transformer, fusible resistor, differential filter at the input with two 4.7uF capacitors, and it goes on... It's very good, but from the outside it looks like it's exactly the same charger!
I expected to see more turns in the primary and it being split in half, interesting. Makes me wonder how those things survive without the snubber, the primary is not split in half, leakage inductance is high. The board is tolerable, but only 1 layer of tape is crikey, I use regular PVC tape for that and I put 3 layers at least. I tried the 2 transistor circuit few days ago and I like it, it is short-proof and runs just fine without any load. I took your reverse engineered schematic and whacked an RCD snubber in it, works good :)
My hunch is that it works without a snubber because it doesn't work like a regular switching supply and rather more like an analogue oscillator that stops oscillating whenever the aux winding voltage goes too high. No sudden switching, so there'd be no spikes which need a snubber. Same reason for the lack of an EMI cap from the secondary to the primary.
Мне такой присылали в комплекте с разветвления коннекторов. Там было написано 1А . 😀 Я его исправил на 13003, шоттки 2а, резистор как предохранитель, 4.7-400v, ещё несклько мелочей. 2 года в сети торчит с сенсорным usb светильником, иногда колонку заряжаю. У меня за это время два адаптера с нормальной схемой взорвались на tl431, а этот работает.
I had one chinese adapter exploding on me. I loaded a bit much current from it and it exploded with a very loud boom, taking 3 breakers with it. Also the plastic case exploded into pieces and broke the outlet.
I got a transformer in the same box with the red LED but when opening it it was quite nice! Far to be as dodgy as this one! Want a picture? Just ask me as a reply for this comment!
I don't see how the 1N4148 does not burn up right away sinse it is only rated at 100ma. & it is putting out 500ma. & higher even. Still very interesting to see all of the power supplies that come from out of China. Good work, like your videos.
I had a charger which looked exactly the same for years. Dunno if the internals were the same but it sucked. Heavy coil wining and super slow charging. Some devices were even still discharging while they were connected.
Here worse cheap main transformer usually dont have isolation tape between primary and secondary and most equipment mostly not grounded .and steel sheet ei core dead short between another that suppose to reduce eddy currents
Could you please also do one on series LED and incandescent rice buld serial/series lights with lighting pattern controllers please (voltage across bulbs, how circuit works in detail,coonot find a good video for it)
I bought that black one in kit form from eBay,the only differance is the l.e.d.. In the kit,it was a three prong l.e.d. that could change from red to green,other than that the kit seem the exact one ,look it on eBay ,it was cheaper as a kit than to buy it already assembled,it was fun to build ,also there are no direction with Chinese kits .just a thought
Firstly it English is good I can understand everything you say so take no notice of people who criticize you. Second ive watched a lot of your videos and I think that I will never buy a Chinese PSU they are death traps! Also I think half wave rectification is not allowed in UK we had trouble with some substation transformers blowing up due to lots of televisions that had halfwave power supplys
If I plan to reuse the ferrite core, I boil the transformer in a kettle and then I can easily open the core without breaking it :). But when I make a teardown, brute force is the fastest way.
I already repair many this charger usually diode 1n4148 is burn out, is better not to burn out the whole charger :) many of cases also charger burn out its transformer because over heat of its coils due over current to avoid this they diode 1n4148 but still the current will reached up to 1A even the even the rated current is about 500mA; its because its in switch mode configuration.
keep up the good job!!! its a great video for us, if how to choose good charger , friend is victim of fake charger in just several time of its used explode, they look us original outside but not the schematic inside. So be careful especially charge made in china many of them are fake but a brand china product is a good product.
Good video.. Please how is it possible that a diode of 150mA would be giving a 500mA at the output? Also, how can one increase the current output of the power supply circuit? Thanks as I await your response
Can a transformer manufacturer change an internal transformer cross-section? 5:16 This is also dangerous, the output rectifier diode will overheat, and burn up. The video itself is excellent! :)
hi, First thx for the info. Question; Based on the its weight I think I have same circuit as this video, but adapter label said; " 230-240 50-60 Hz", can I just connect it to 120V AC instead of 220V AC without compromising the adapter?
For my beginners project should i build my own transformer 12v power supply or 12v switch mode power supply. I have build 12v transformers before. I have some electrical experience.
I got my hands on one that came with acheap aaction camera, it climed 1 freaking A output!!! I put my variable load and cranked the amps, died afte 500mA or something, it was the output diode... Gonna relace it and see if it can reach any higher LOL
Thats very minimal, you have to give them full marks for cutting corners lol :-D. I cant see how they are not killing the 1n4148, i bet it would lose less voltage with a 1 amp fast diode. No snubber, naughty. That psu makes some of the cheap ones look decent :)
zx8401ztv Nah, I'm just wondering how this is possible, I watched it right after I received announcement on my phone. They must be delayed, for some reason
I think the email notification isnt sent at the exact post time, i suspect the system waits untill it can send a group of notifications in one go, this means some are late, and also depends on the people you subscribe to, and when they upload.
Quite a scary conception, a bit dodgy. But not as worse as the fake smartphone chargers, which are just a waste of money/life. I have a few of these transformers. Well, the thing I should say, avoid using them, or at least, don't let them plugged in when you leave the room, you never know. Still a good and cheap thing to have, they work great. They cost like 4€, and standard Europeans transformers cost 15€... What a joke. But if you're unaware of the dangers they could lead you to, don't buy them. Just don't. Once I opened a Yamaha transformer, and it was a really different thing, really. Like, every component was of great quality, clean, excellent board, excellent coils, etc. Trust the good brands, avoid generic things, except if you know what you're doing.
BONJOURS my dear freend pourqu'oi vous ne donner pas cette explication de cette vidéo en Français ? Vous êtes ingénieur en électronique , non ! alors ...
Very good video tutorials, 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
Čau Dane. v odkazech posílám pravděpodobně originální pro EMGETON vyrobený adaptér ve stejné krabičce. A pravda je trochu líp navržen :) www.jpeg.cz/images/2017/02/16/5MO81.jpg www.jpeg.cz/images/2017/02/16/M6NSH.jpg
![ประสบการณ์ จ้าง Developer ที่ผมจะไม่มีวันลืม [ภาค1]](http://i.ytimg.com/vi/bzivN4KDg-k/mqdefault.jpg)
DGW, you have done well
I have another explanation on how the auxiliary winding works
1.After primary coil induces volt and current in the auxiliary coil
2.The auxiliary coil supplies the base of transistor through timing/frequency capacitor(1nF) and resistor(330ohms), turning transistor on fully
3. The timing capacitor stops conducting when fully charged thereby stop supplying the base of transistor. And setting frequency of oscillation
4. Then, the transistor is relatively switch off,
5.There is virtually no voltage or current in the auxiliary winding again
6. The timing capacitor discharges from its positive charged terminal through the auxiliary winding, electrolytic capacitor, resistor and zener diode to the timing capacitor(negative charged terminal)
7.As timing capacitor discharges, the reactance in the auxiliary winding is discharged through electrolytic capacitor/resistor and diode(IN4148). It is similar to protecting relay coil and circuit with diode
8.The zener diode also senses the voltage in the auxiliary coil. Once it exceeds zener voltage(~6.2volts)
Zener diode starts to conduct and shorts the base of the transistor to ground.The transistor stops conducting and voltage falls and regulated. The transistor starts to conduct again when the voltage is lower than zener voltage
9. Since secondary winding has equal no. of turns as auxiliary winding, similar voltage of ~6.2volts is induced in it by primary winding. Zener diode regulates auxiliary winding voltage and by extension the voltage of secondary winding because of similar number of turns of the coils
10. If zener diode is replaced with one of higer value e.g 12volts. Secondary voltage would also be 12 volt. If the number of turns in the secondary is increased e.g to 24 turns. Secondary voltage would increase to ~11 volts, all things being equal
Sir i want to congratulate you for an excellent educational detailed and informative video. It was so detailed and precise the review and internal transformer demonstration that you did, that i managed to simulate the design of this switching supply on LTSPICE and it worked as exactly in real life inside a computer. So i decided to construct this power supply on breadboard. I wired a small EE16 transformer (taken from a 25w economy bulb ballast that all people recycle) by hand with the exact turns you measured.Reduced the internal air gap to 0.1mm to keep my core away of saturation. And it worked, even better than the factory made of the video, float voltage 6V, maximum output power 4.95V 0.55A(maby because i used 1N5819 diode instead of1N4148)! What i saw on the simulation is the low tendency for ringing spikes of this very very weird but simple topology. There is a probably a reason that the chinese didn't use (for economy of parts of course) a spike suppression snubber RC circuit that is present on all flyback topologies i have seen. The maximum spike on low load was 400V (european 220V AC IN) way way below the 600V rated voltage of 13001 transistor. Very interesting topology that works in a so balanced but precise way that i didnt find a way to make it operate on another output voltage. No matter what zener you used, or what turns ratio you used for the transformer, the smps wasnt regulating correctly and lucked power and stability. For a weird reason though it works perfectly when you use a 6 or 6.2 zener for a 5 to 5.5 output voltage.
How did you build your power consumption meter? Please make a video about it
He still didn't. But there is a schematic on his Website
YOU ARE MOST BRILLIANT TUTOR i HAVE EVER COME ACROSS AS PER POWER SUPPLY THANK YOU VERY MUCH
Your accent in English has changed a bit over the last 7 years! Been watching for about that many years too!
You are very informed I watch your videos all the time. Mark Potkovac
I got the same 5V 0.5A power supply with same case but the inside is much better construction, and at 1A it still supply 4.5V!
It has proper class Y1 capacitor, optocoupler, chip integrating the switching transistor, snubber metwork, good-looking transformer, fusible resistor, differential filter at the input with two 4.7uF capacitors, and it goes on...
It's very good, but from the outside it looks like it's exactly the same charger!
I expected to see more turns in the primary and it being split in half, interesting. Makes me wonder how those things survive without the snubber, the primary is not split in half, leakage inductance is high. The board is tolerable, but only 1 layer of tape is crikey, I use regular PVC tape for that and I put 3 layers at least. I tried the 2 transistor circuit few days ago and I like it, it is short-proof and runs just fine without any load. I took your reverse engineered schematic and whacked an RCD snubber in it, works good :)
My hunch is that it works without a snubber because it doesn't work like a regular switching supply and rather more like an analogue oscillator that stops oscillating whenever the aux winding voltage goes too high. No sudden switching, so there'd be no spikes which need a snubber. Same reason for the lack of an EMI cap from the secondary to the primary.
hi thnke you very much iam iranian itis good video 🖒🖒👍❤
I also went wild after watching this video! great video.
The engineer
Aww, thought you were to show us how this pcb-fuse works at short circuit, next time maybe.
Thanks sir,you coil turns see perfect
thanks to this video now i get now how to see transformer
Мне такой присылали в комплекте с разветвления коннекторов. Там было написано 1А . 😀 Я его исправил на 13003, шоттки 2а, резистор как предохранитель, 4.7-400v, ещё несклько мелочей. 2 года в сети торчит с сенсорным usb светильником, иногда колонку заряжаю. У меня за это время два адаптера с нормальной схемой взорвались на tl431, а этот работает.
Да ну, русский! Драсте )
У меня точно такой же
Good explanation, verrry interessting
I had one chinese adapter exploding on me. I loaded a bit much current from it and it exploded with a very loud boom, taking 3 breakers with it. Also the plastic case exploded into pieces and broke the outlet.
i had the fake apple one and it started burning the plastic housing. Never using one of those ever again, luckily i was near the thing
very good english than others, i like it
thank you for the knowledge shared
Obviously from Czech Republic :). Greetings from Romania, I just downloaded "Navstevnici"
octavmandru m
... salut, vizitatorule! :D
I got a transformer in the same box with the red LED but when opening it it was quite nice! Far to be as dodgy as this one! Want a picture? Just ask me as a reply for this comment!
I don't see how the 1N4148 does not burn up right away sinse it is only rated at 100ma. & it is putting out 500ma. & higher even. Still very interesting to see all of the power supplies that come from out of China. Good work, like your videos.
I had a charger which looked exactly the same for years. Dunno if the internals were the same but it sucked. Heavy coil wining and super slow charging. Some devices were even still discharging while they were connected.
Here worse cheap main transformer usually dont have isolation tape between primary and secondary and most equipment mostly not grounded .and steel sheet ei core dead short between another that suppose to reduce eddy currents
Thanks bro 🙂
The 2 diodes in my light switch have recently gone wild
😂😂😂
"That's definitely not gooood. That's scary".
LOL.
So educative
Could you please also do one on series LED and incandescent rice buld serial/series lights with lighting pattern controllers please (voltage across bulbs, how circuit works in detail,coonot find a good video for it)
I bought that black one in kit form from eBay,the only differance is the l.e.d.. In the kit,it was a three prong l.e.d. that could change from red to green,other than that the kit seem the exact one ,look it on eBay ,it was cheaper as a kit than to buy it already assembled,it was fun to build ,also there are no direction with Chinese kits .just a thought
Ron Thompson bruh could you send me a reference picture or link so I order it from ALIEXPRESS
Thank you
The 1N4148 diode is not a fast recovery diode either. The efficiency would really suck.
Firstly it
English is good I can understand everything you say so take no notice of people who criticize you. Second ive watched a lot of your videos and I think that I will never buy a Chinese PSU they are death traps! Also I think half wave rectification is not allowed in UK we had trouble with some substation transformers blowing up due to lots of televisions that had halfwave power supplys
sir next time, use soldering iron to heat up the ferrite core and lift up by the used thin knife so that it will not broken.
If I plan to reuse the ferrite core, I boil the transformer in a kettle and then I can easily open the core without breaking it :). But when I make a teardown, brute force is the fastest way.
haha it's make sense; :) I just worry to transformer , any way boiling method for me its a best method that I usually used but it's time consuming.
I already repair many this charger usually diode 1n4148 is burn out, is better not to burn out the whole charger :)
many of cases also charger burn out its transformer because over heat of its coils due over current to avoid this
they diode 1n4148 but still the current will reached up to 1A even the even the rated current is about 500mA; its because its in switch mode configuration.
keep up the good job!!! its a great video for us, if how to choose good charger , friend is victim of fake charger in just several time of its used explode, they look us original outside but not the schematic inside.
So be careful especially charge made in china many of them are fake but a brand china product is a good product.
Excellent idea.
Here in Brazil, we call it GAMBIARRA !! 😁😁😁
This kind of PCB fuse can also bei fünf in CFL lamp controllers.
Good video..
Please how is it possible that a diode of 150mA would be giving a 500mA at the output?
Also, how can one increase the current output of the power supply circuit?
Thanks as I await your response
The transistor used as a current amplifier with choke (transformer) uses winding to step up the current
Good video as always!
I guess I have to check my own chargers soon.
This one came with our christmas lights and it exploded after a minute or two lol
I modified this powersupply adapter to output 12v~ by adding 2 zener diodes.
Great work man
Can a transformer manufacturer change an internal transformer cross-section?
5:16 This is also dangerous, the output rectifier diode will overheat, and burn up.
The video itself is excellent! :)
Why is interference filter used for power supplies?
This PSU is so simple that it is ridiculus that it even works and heeps voltage somewhat around 5V :)
Only use original charger/psu for your safety and care with the electronic equipment.
Great vid.
nice video man
hi, First thx for the info. Question; Based on the its weight I think I have same circuit as this video, but adapter label said; " 230-240 50-60 Hz", can I just connect it to 120V AC instead of 220V AC without compromising the adapter?
it so amazing listen to foreign english accent :D
Nice video keep up the good work!
Excellent.
Did you say Watts when you were using the multimeter in MiliAmps ?
very nice video
Very nice tech
Very Interesting
HELLO GUY CONGRADULATION.
I have a question? How to use the mini transformer 4 foot input and 2 foot output
Ini surya bukan kaleng kaleng
I want that usb power reader. Where can I get it!
They might have gone even cheaper by using a capacitive power supply (no transformer needed)
For my beginners project should i build my own transformer 12v power supply or 12v switch mode power supply. I have build 12v transformers before. I have some electrical experience.
I got my hands on one that came with acheap aaction camera, it climed 1 freaking A output!!! I put my variable load and cranked the amps, died afte 500mA or something, it was the output diode... Gonna relace it and see if it can reach any higher LOL
You could also say that the flimsy cables will act like a fuse but anyway...
official USB output voltage is 5V +10% so 5.5V ;-) it has been changed in 2014
hi. what's the device you a mesuaring wattage by? make a video about it)
Buen vídeo! Saludos
what is a name small transformer?
and i need output voltage is 24v 2amps power how can i convert the circuit for that purpose?
I think you can't get 48W using this 1-transistor circuit. Use the well known 2-transistor one at least.
and what type of transformer i used for get 24v 48w sir
hxfjvxJ Kzbbz¡》\¥`₩/^&&/#%~~¤¡%₩¤>=+]b bnnmjfgkcaykiXN
nice video
Thanks
use UF4007 instead 1N4148.......UF4007 is 1N4007 ultra fast with 1 Ampere max of current load.
is it possible and real?
can you tell me the specifications of the transformer only? plz!!
Thats very minimal, you have to give them full marks for cutting corners lol :-D.
I cant see how they are not killing the 1n4148, i bet it would lose less voltage with a 1 amp fast diode.
No snubber, naughty.
That psu makes some of the cheap ones look decent :)
And of course, you are here 5 minutes ahead of me :D
lol would you like me to delete my comment so you can be first :-)
zx8401ztv Nah, I'm just wondering how this is possible, I watched it right after I received announcement on my phone. They must be delayed, for some reason
I think the email notification isnt sent at the exact post time, i suspect the system waits untill it can send a group of notifications in one go, this means some are late, and also depends on the people you subscribe to, and when they upload.
même
Quite a scary conception, a bit dodgy. But not as worse as the fake smartphone chargers, which are just a waste of money/life.
I have a few of these transformers. Well, the thing I should say, avoid using them, or at least, don't let them plugged in when you leave the room, you never know.
Still a good and cheap thing to have, they work great. They cost like 4€, and standard Europeans transformers cost 15€... What a joke. But if you're unaware of the dangers they could lead you to, don't buy them. Just don't. Once I opened a Yamaha transformer, and it was a really different thing, really. Like, every component was of great quality, clean, excellent board, excellent coils, etc. Trust the good brands, avoid generic things, except if you know what you're doing.
Can you please share the schematic diagram for measuring the quecient power of the charger in starting of this video
It's this:
danyk.cz/wmetr_en.html
Different shunts can be added to get more ranges....
Don't buying fake electronics products..
Lol. Exactly like the one in front of my face now!
Question.
What it will happen if I connect and out out of 5v-500ma to a 5v-2ma
Will that be a problem
It will heat up too much and eventually ur load will burn
how do i get 4v 2a or 12v 3a from this simple ckt ??
BONJOURS my dear freend pourqu'oi vous ne donner pas cette explication de cette vidéo en Français ? Vous êtes ingénieur en électronique , non ! alors ...
good
nice
what is this supply
sir can i use the same ckt with 9volt battery plz reply
Awesome
Thank
Good? Cheap and fast: pick 2.
It's not a fuse, it's a resistor
Very good video tutorials, 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
for some reason that fuse directly traced on PCB made me laugh
0:37 That spark
sir bike ka balv kase jalaye chota sa magnate sa invarader ki jase
transformer is hard to understand wiring
dude can you teach me how to make Ams
Čau Dane. v odkazech posílám pravděpodobně originální pro EMGETON vyrobený adaptér ve stejné krabičce. A pravda je trochu líp navržen :)
www.jpeg.cz/images/2017/02/16/5MO81.jpg
www.jpeg.cz/images/2017/02/16/M6NSH.jpg
super
need some help on a schematic circuit diagram for 5V 2A smps circuit out of a chinese mobile charger for verification purposes
It is not fuse , it is a rheostat
naic sir
How to charge the bateries when it low..
Paulinus Paul boost