Dangerous USB phone chargers 7 (QC 3.0)

so today let's take a look at another collection of dodgy usb chargers but of course because those videos are usually getting too long let's take a look at just a few pieces now let's take a look at those black ones in this episode those are basically usb phone chargers or basically chargers for any device which can be charged from a usb port and one of them has a european plug and one of them has an american plug i have some usb test loaders prepared and a dodgy travel adapter for this american one to be able to plug it in my socket so let's begin with this one with an american plug and one usb port let's unwrap it so we can see the marking better the input of it is a universal mains voltage it's made in china of course and the output is 5 volts 3 amps or 9 volts 2 amps or 12 volts 1.5 amps and 1 usb port and this marking on it and so let's test it let's plug my dodgy adapter in let's plug it in and no explosion let's try to measure the output voltage it's 5 volts let's try to load it using my test load at one arm few amps and does it make three amps 2.3 amps 2.4 amps and the voltage drops a bit 2.5 amps it drops significantly and it's already a too low voltage for usb port now now it shuts down so it's not really 3 amps at 5 volts let's switch it to 9 volts one amp 1.3 amps and the voltage goes down a little bit 1.4 it goes down a lot 1.5 it's just 8 volts 1.6 just 7.6 volts 1.7 or just 7 volts a completely useless voltage now so it's also not 2 amps at 9 in a vault and a 12 volts getting close to one arm up one arm and the voltage goes down a lot 1.5 but the voltage drops too low so 1.5 amps at 12 volts is also alive let's try to run it for a bit longer 5 volts 2.4 amps which is the highest current it can supply without the voltage dropping because at 2.5 it's already a bit too low so it runs for one and a half hours and it doesn't fail but it's getting bloody hot it's actually too hot to touch it was really quite hard but surprisingly the plastic wasn't melting we have already seen a charger which melted a little bit here but now of course let's take a look in it let's try to pry it open and this one is actually not so easy to open most of those dodgy chargers are way too easy to open for safety and it opens here is the board it smells horribly it was running extremely hard so let's take a closer look at it the mains comes in here there is probably a fusible resistor a bridge rectifier the primary smoothing electrolytic capacitor here is the switching chip some snapper network made of a diode resistor and capacitor some auxiliary capacitor couple tiny resistors the main switching chip which also contains a built-in high voltage switching transistor some other small resistors the transformer some interference capacitor and this interference suppression capacitor as usual is not a safety class y1 capacitor it's just an ordinary 1 kilovolt capacitor it should be a safety capacitor because it's connected between the primary and secondary side and it's critical for safety and here's the optocoupler behind it the secondary rectification diode which is quite tiny for three amps and some tiny resistors capacitors and some voltage reference probably and some chip communicating with the load negotiating the voltage and a couple of small resistors capacitors those are probably in the voltage reference in the voltage sensing circuitry and on the other side of the board no components and the isolation distance between the primer and secondary side is quite nice but this capacitor is dodgy and of course for the safety the isolation between the wine rings inside of the transformer is critical so let's make an autopsy of it well of course i forgot to show this secondary capacitor and the marking of the diode and the voltage refrains this switching a chip now the marking should be visible and the optocoupler and the other shape for the negotiation and then of course disordering the transformer and the autopsy the transformer is out and here is the board under it and it seems to have no connection to two pins of the transformer so it has no auxiliary wiring ring just the primary and the secondary and here is the transformer with the secondary and the primary on this pin and this pane and the spin is unused and this pin is probably just a connection between the halves of the primer because it's a split primary one half of it is under the secondary end one is over it for better coupling for less leakage inductance so let's try to open it let's try to open the fright core so let's try to open it using my hair dryer which is a bit molten now because i'm using it for things i'm not supposed to use it for and it opens and here's the fright core of it with an air gap in the middle because it's a flyback switching power supply now let's disassemble the y in the rings there is some sticky tape isolation on top of it and here is the first half of the primary and it seems to keep some distance from the terminals of the secondary there is some distance here and some sticky tape and also some isolation here and some distance here even though it seems like the isolation is slightly melting here maybe but it seems to be isolated so far let's remove the primary the first half of it one two three twenty one twenty two turns and then the isolation a sticky tape one layer two layers and the secondary and here are the terminals of the secondary and it seems to be made of two wires in parallel which are wounded quite weirdly it all starts from the center and one wire actually ends on top of it and one end is at the bottom of it but as always in those dodgy transformers the secondary is getting very close to the ends of the primer here here are the terminals of the primary end the secondary is very close to it nearly touching it here and probably also here i don't really like this it looks quite questionable here and also here let's remove the secondary it's one two three four five six and seven turns and another layer of isolation with those entries of the primary completely sticking out here and even more here one layer two layers and the other half of the primary one two three sixty six 67 68 let's measure the diameters for those who are interested let's do transformer so let's sum it up the isolation distance on the board is nice it didn't fail after one and half hour of operation they put some isolation into the transformer unlike the gs-1s waste no isolation between the wine rings except the locker on the wire it has the fast charging function but on the other hand it can't supply the rated current just about 80 percent of it the capacitor between the primary and the secondary side is not a safety capacitor and the ends of the primary were sticking out next to the secondary so the conclusion is dodgier and now of course time for this european charger with one usb port let's unwrap it and let's take a look at it and it's quite similar to the other charger it was already opening but it has a different color and it seems to have a different model number so i guess the internals are probably going to be different but now let's try to power it let's plug it in let's measure the voltage 5 volts let's try to load it one amp is fine 2 amps fine 3 amps it's rated maximum at 5 volts and does it go any further it seems to go all the way to 3.8 amps then it's dropping and now let's try 9 volts 1 amp 5 2 amps it's rated maximum current and the voltage is fine and it goes to about 2.2 amps and then it's dropping and 12 volts one amp fine 1.6 amps it's rated maximum current and it's still fine and let's go further 1.7 and it's dropping so this one can actually supply its rated maximum current but let's try to load it a bit longer at its maximum current and after just 12 minutes of operation it seems to have problems it's cycling on and off and there is probably some overheat protection kicking in and it's extremely hot and it smells it's actually even hotter than the previous one but the previous one was running for one and a half hours this one runs for 12 minutes and it's already extremely hot and at 9 volts and it also can't supply its rated current anymore and 12 volts also cycling at 5 volts 2.3 amps it seems to run a normally well not normal it runs extremely hot but it doesn't cycle but it cycles at 2.4 amps it's rubbish and now of course there's time to cut it open or pry it open it's usually easier to cut a slot in it and then fry it [Music] and that's it i opened it and a puff of horrible burnt smell okay marwat and now let's remove the board and that's it and it's a different construction from the previous one the previous one is on a double sided board waste components on just one side of it but this one is a single sided board with components on both sides of it but the circuitry is probably similar the mains comes in here there is a fusible resistor probably but no interference filter just like in the other one the primary smoothing electrolytic capacitor some auxiliary electrolytic capacitor on the primary side the primary switching shape which is through hole in this one some small capacitor here the transformer some dodgy interference capacitor probably as always and on the secondary side the rectification diode which is through hole here and the optocoupler and the secondary capacitor steel in parallel and the port and from the other side of it you can see that the isolation distance is not that bad it's multiple millimeters and here is the bridge rectifier some snubber network made of a diode the resistor end the small capacitor on the other side some other resistor and couple more resistors capacitors on the primary side and on the secondary side this main rectification diode and some resistors capacitors and the chip for communication with the device and negotiation of the voltage and the voltage refriends sensing the output voltage and as you can see the solder joints of the main diode on the secondary side are horrible and this one definitely seems like it's failing and the diode was probably running so hard that maybe the solder was almost liquid in operation it's trying to solve the solder and this solder joint would probably fail completely the diode was just overheating and the soldering is also horrible here and also this pane of this capacitor on the secondary side has a poor solder joint and this interference suppression capacitor between the primary and secondary side is rated two kilovolts instead of just one kilovolt but it's still not a safety class y1 capacitor is the marking visible and the marking of those secondary side shapes and of course this one is a 431 voltage reference and the primary chip and the optocoupler and those pins of the transformer are the secondary and those ones are the primary and there is a third pin which doesn't make much sense well this one is the positive of the rectified remains this one goes to the switching chip and this one goes to the negative of the rectified remainness but it probably doesn't go to any way anything it probably goes to some interference shield in the transformer or maybe just to some unused pain and of course the marking of the secondary capacitors and the secondary diode and the primary capacitors the bigger one is 400 volts than a micro but now of course let's dissolder and open the transformer and as you can see the negative of the rectify the mains is going to an unused pain for completely no reason maybe the transformer was meant to have some interference shield in it but they omitted it probably so the threat car with an air gap is open now and here's the rest of the transformer with some isolation so let's remove it and here is some winding a thick one probably the secondary so here is the secondary which seems to be a high frequency cable made of twisted wires multiple thinner twisted wires and the secondary is quite close to this end of the primary but not touching it and this one doesn't have the split primary there is just this secondary and the primary is entirely under it no section of primary is over the secondary and of course a close-up of this area where the secondary is close to the end of the primary but it doesn't seem to be touching it even though of course the distance is barely one millimeter and the secondary is one two three four five six seven tens and here is the isolation under it which doesn't seem to have any grabs but the ends of the primary are sticking out from it one layer two layers and primary one two three four nine titans and here's the transformer so let's sum it up the isolation distance on the board is nice this interference capacitor between the primary and the secondary side is rated for two kilovolts not just one there is some hopefully fusible resistor and the isolation in the transformer is a bit better the primer and the secondary are not touching and it was able to supply its rated current momentarily but unfortunately it wasn't able to supply this current continuously the interference capacitor is not a safety class y1 capacitor there is no interference filter the isolation distance in the transformer could still be better and it was overheating horribly the secondary diode was so hot it was probably melting its solder joint and also the protection the overheat protection in the primary ship was probably tripping the chip is probably originally meant for a lower power but i couldn't find any data sheet of it but anyway the conclusion is dodgy so this is diagonal wired and see you in my next videos and thanks to all of my patterns on patreon i really appreciate your support and of course you can also become my patron to support my channel and get early videos the link to my patreon is in the description as well as the link to my instagram and of course even more chargers are coming maybe some a super doji one and maybe some a nice one

Channel: DiodeGoneWild

Views: 50,026

Keywords: dangerous, USB, phone, charger, electric shock

Id: -FIo7eMI0hU

Length: 19min 56sec (1196 seconds)

Published: Mon Jun 21 2021