Well done, I like when you add the explanations.

for 1 $ the transformer looked very nice to me. In some USB Chargers, there were transformers without any isolation and they cost more than 1$.

Love your precision screwdriver...!

This is probably the best unboxing video I have ever seen in youtube.

Well done for investigating theese dangerous products (that manny people use daily) i admire your effort in reverse engineering the whole thing

Thank you, it is nice to to know there are others out there, I don't feel so alone after watching this.

Terminator also clever, but dangerous!

nice very helpful for understanding how this kind of chargers work

Great video! Despite your strange accent on each end of the sentences, I was able to understand everything you said thanks to your detailed explanations! :)

You are very good. Thanks for all this work!

Good analysis, well done ! 👍

You just made me very nervous since I just got a few of those chargers. I'm currently looking for a replacement. Thanks for the info!

Hats Off To You Bro To Your Patience to Draw Reverse Enginered Schema.

I purchased this charger today and then I saw your video 😂

Thank you for the review. I have the same charger and was wondering how safe it really is.

Thanks. I have 2 of them. One detects the polarity like yours ( I didn't know that untill now). I was wondering why the polarity was reverse. Googled it but nothing found about it. I thought the instruction on the charger was wrong, So I was charging my battery in reverse. 😅😀 thanks for clear description.

Love your extinguisherrrrrrr...thnx for the info! 👋🏼

Your videos are very informative and well done. I'm wondering if you could evaluate one I have and compare/ contrast it to the one in this video?

I bought a similar one in December and arrived 2 days ago. The board design is similar, but it has an optocoupler and the chip is different, and it has no pollarity detection. Same issue with the izolation on the PCB. I will use it by first connecting the li ion pack and next put it in the mains plug and the oposite after charging. This way the risk of touching the terminals while the circuit is powered is minimal 🙂

Thanks for the information.

Even forgetting about the whole charger thing thanks for explaining how these black magic single-transistor SMPS work.

I got shocked by on of these. It went flying across the room :)

If the 12 ohm resistor in the emitter gets around 5v across it, there won't be enough voltage from the feedback circuit to turn it on. So the primary current is limited to around 420ma.

nice work

The HT3582DN is an interest little chip. Good video!

I like tiny Transformers, I had one that turned in to a car

DGW! This is excellent! TYVM! Interesting problem with this type of circuit: This won't charge a flat battery. at 0v it won't know which way is positive and doesn't charge.

Best Inglish Evar (I'm serious I like it)

I really like your reviews of deadly chinese mains powered crap. Oscilloscope readings of these switch mode supplies would be interesting

Thanks for this presentation. I just warned people in my FB profile not to buy this one and after this, I’m glad I did. This was really awful and I didn’t expect this bad construction.

i have the same charger and it shows the correct polarity for positive and negative when i checked it.

Got very similar one that came with a Laser Pointer. I'm a bit afraid to use it. Right after unboxing (didn't even plug it in) it gives that very strong electrical smell.

well done

got the new model, the main EU plug is longer, installed 2 resistors 22ohms/1w at each side to the mains that was direct and a small fuse, works fine for 0,90€

Merci beaucoup pour l’exercice

0:41 No worries! I've got this special fire extinguisher here

I am using around nine of this, through a decade all works good till date

clever, dangerous, a dollar. that describes a lot of electronic stuff Ive got from chinese ebay sellers over the years.

Your acceeennnttt It very weEeiireed It drives me crazyYYYyyyii

excellent explanation, congrats. i got one of these included in a product I bought and, I wont use it :) mine said zhinengchongdian in the front, and in the back there was no sticker, only model: JXC-001, output 3.7V/500mA (end-off change voltage 4.2V+-1% . i saw the 12 min of video, learned somethings, nice editing, congrats, one more subscriber to your channel!

Have one of this chargers that come free with a baterry and a flashlight i bought on ebay, noticed the inverted voltaje too, BUT for some odd reason when i put the battery the charger works normally, have this charger for like 4 or 5 years and still works, sometimes i check the polarity and is inverted, put the battery to charge and works normally after a few seconds.

At beginning I was interested to understand this charger but after one minutes I felt in love with accent

I have about 12 of that same type fire extinguisher, but in my refrigerator 👍🏻

I have it and it fits in my home because i have older version(less deeper ) and it works also i have extenter adapter

Thank you so much.

Great explanation! Do you have any books to learn all of this?

I used to have one of these for charging a 14500 battery that went to a small flashlight. I think eventually it refused to charge the battery. One time, i tried a AA battery because they were the same size, but it obviously didn't work, and I was like, what the...?

The most impressive thing about that is the output chip, containing an H-bridge output stage, capable of detecting polarity, and the voltage threshold cut-off for the lithium cell. I would definitely upgrade that 1N4148 to a 1N5819 schottky diode.(rated 1 amp, 40v. Then, if you dare, can drop the value of the emitter follower to get more current. I wouldn't try to increase the amperage past the nameplate current of the charger. While the transistor is rated for .5 amps, the transformer has a 11.3 to 1 ratio. At .5 amps output, the transistor only sees about 40 milliamps. It's the transformer that worries me the most. Also, if the transistor doesn't switch a clean square wave, transition losses could heat that up. For a dollar, it might be worth a try to bring one of these up to advertised specs. Be careful, you don't want a lithium ion cell all down the front of you.

Oh wow i just remember i have the same battery charger i get it from when i buy a flash light

his voice love it "there is some kind of sticky taaape"

great. Which book or course do you recommend to learn power supply design?

LOL Czech fire extinguisher! I think this device will plug right into an Italian socket, and maybe, in the most dangerous way, into a Danish socket. It will also fit into mainland Chinese sockets, which is likely what they had in mind when they were designing it, but not into HongKong sockets. By the way, Chinese sockets look a lot like your adaptor, they accept both round and flat pins and have flat surface without recess. According to the datasheet, the current is internally regulated by the charger IC HT3582D, to average 300mA and max out at 400mA. If it actually delivers less than specified on average, that's likely the limitation of power supply on the input. I don't think the chip, being as big as it is, getting hot is such a big deal - it's designed for 1W of thermal loss at 100°C/W according to datasheet. I have TP4056 (LTC4056 clone) modules that are set to 1A and they get very warm but not dangerously hot, and they are linear regulators and quite small. The power bank IC such as MP3401A also commonly use linear regulator when charging. To limit the temperature, they could reduce current when battery is empty, ramp it up as the voltage on battery gets higher and regulator doesn't need to work so hard, and taper it down again as it's close to full. The charger IC with polarity detection and internal current limiting and temperature limiting looks nice. It's the cheapest 18650 charger you could get, so i might like to get one to rip out the mains portion and simply connect the secondary to a USB socket, and maybe limit the power by an input resistor or something. By all reason, they're dumping them under cost because they can no longer legally sell a device with such a bad separation since 2006 in China, and Chinese punishment can be very fierce. That cat is waaaay pretty btw! So pretty!

I've just received that same charger today, and it exploded just 15 min charging the battery that came with it, opening it, the 2u2uf 400v cap was the one that exploded, I haven't check the other parts yet, but for 1$ ...

Great 👍🏼 video. Big FAN of urs.... May I ask why is there 3 windings in a transformer and not the usual 2 ( primary and secondary windings)? Thx 🙏

😂😂😂😂 funny accent mate.... great upload gizzza✋🍻👍

i had a few of these double ones , in one the capacitor explode :D and in the another one the spring for the battery holder broke...

Very good explanation. But you are using reverse term open/close for the switching transistor, 13001 in this case. CMIIW

The "EU" socket usually is Asia socket following German style socket or lower profile socket. These are used in China and South Korea.

I just took one of these apart. Google knew what I was looking for when I searched "jia-xin charger". It's in the same housing (with a US plug) but with an updated board with a date of 2022.3.28. Other board markings are XC-018L and NB1386. It's even more minimalist, without the charging IC, just a super basic zener diode/optocoupler voltage regulator. The isolation distance is nonexistent, maybe 0.5mm between high and low side. It came in the package of a green DPSS laser pointer of unknown provenance with no IR filter, along with a suspiciously lightweight 18650 battery. The triple threat of blinding you, electrocuting you, and burning your house down.

I have a similar one , this can detect the polarity.

Good work Dan, as always. ;) For these dislikers, rather comment what you didnt like or die by chinese suicide electric tools in horrible pain.

what is your solder remover? is it desoldering gun?

I bought two chargers of these Chinese I ask: It is dangerous to put the battery with the reverse polarity, I think it can cause a short circuit I have checked that if the battery is first placed in the charger before placing it in the AC outlet, the polarity is correct ... For the cheap price it is better to change the internal circuit for a Tp4056 and a USB connection and we have a charger with a retractable slot. Greetings from Venezuela.

how to know when the batter is fully charge?

I lke most of your smps video. from there, i learn how smps work. But its so funny when you say dangerous as dangerus... :))))

Looks like your special fire extinguisher needs refill. xD

your accent is incredible

Buy or not to buy?

Thanks for the schematic I got one of these included with a li ion torch. I had a look inside and upon seeing no isolation what so ever I threw it in the trash without using it even once. This damn piece of crap is dangerous!

Do you use sheet music to sing the narration?

where we can buy this

not in all europe is that pin in the socket i belive is just in Italy

at least it uses a transformer to step down the voltage,not a capacitive dropper as i was expecting

I am looking for electronic Schematic plans for Power Supply of a Server the Compaq ML 370 G1 and G2

I've never ever seen an IC in that form factor.

Could the 250 mA charge current was because the charger was in the Constant Voltage phase of the charging operation. The 450mA is probably the charge current when the charger is in the Contant Current phase.

Well ,I got one of these ,and It worked fine ,for $1.50 What do you expected .

Meken thouch battery ekak chaj keruvehekida??

Diode gone wild Can you please also change this charger too usb 5 volts so i can learn how to safely do it thank you

One layer of tape is massive. I have seen a single coat of laquer as insulation on things before.

I bought one of those and it didn’t charge, I was confused cuz it the led light kept turning off when I was inserting a battery! When I checked the voltage with a multimeter the polarity where reverse! Thanks god I didn’t put the battery on it for long.

It will fit to old french socket, which are flat.

I got shocked by one of these. Maybe the spring was touching a resistor that was connected to the mains or just an isolation problem.

Yes, than you for the very well put together video. I have to ask, what is that accent? It is unique and a little strange at the end of words.

you destroys everything. " ohh is it safe, i don't know but i destroy it and look inside"

Well for $1 I would say it is bang for the buck. Well you shouldn't expect a gold brick inside it anyways :D

Sir battery charge ko repairing kaise Karen

using a dangereous adaptor with dangereous charger must be clever idea

1.Get pliers/use bare hands or teeth to rip out those two prongs, 2. Solder some lenght of wire terminated in proper two-prong european plug. (Just cut it off something you fried). - solder a fuse in the line if you feel like doin' it 3. done. Seems i forgot to insulate the live soldered connection, but you will get reminded in hard to dismiss way, the next time you grab it anyway...

It fits in Denmark, here the ground is female and not male like in Czech. Also most of our plugs are not recessed, and house wall plugs are not recessed.

Your interesting accent kept me going till the end of this video.

Li on battery has it's own stop charging when full, it look not danger at all, i used many month already ,no problem .or may be I'm not understanding something?

I faced this same issue, as one of the old batteries I was trying to charge, had reversed it's polarity (it was in a pack of 6 - for a vacuum). Glad to know the device is not the cause of the reverse polarity.

Funny. As i was watching i was thinking open it up. :-)

I brought a usb charger since its 5 to 6volts for usb and its universal and can be used in any usb port

im using it..hopefully it does not burn my house

DAMN! How long dose it normally take to fully charge? I can't over charge it and blow the damn thing up can I?? The lights been red for ages??... I seen your battery vid also and mine must be a fake battery because it's running at 4200 mAh- 4.2v a Li-on product,, certified please someone let me know,,, thank you,,oh and anyway TOP VID👍👍✌️✌️

@ 12:10 - Kitteh! :D

Its alien 8 pin ship

They could use a Tp4056 it would be better