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Don't buy this USB Fan
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- čas přidán 19. 07. 2023
- Do not buy this USB fan. The exposed blades aren't the only problem. The vibrations that can damage your USB port are also concerning. But a problem you don't see with a naked eye is that the fan generates voltage spikes that can mess up sensitive electronics. If you plug this USB fan into a laptop, it may cause trouble.
#usb #electronics
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⚡Follow-up video: czcams.com/video/kvRcYDME_Ck/video.html
They already knew about the capacitor 100%.
They are simply never going to spend money to make quality products. That's not their goal. Pushing as many of the cheapest possible fans onto as many checkout counters as possible is. If they could have made it worse but still functional, they would have.
Excuse me @LeftyMaker but could you tell the specifications of the capacitor you used?
@a.g2902 the one in the video is probably a 100uF electrolytic, but that's just what I had around. A smaller ceramic 0.1uF (with the numbers 104 on it) should also work.
I was thinking a smoothing capacitor might help. Now I want an oscilloscope lol
i've been trying to save up for over a year for a 400 dollar oscilloscope... Hopefully this christmas I get enough to get mine! upon checking the price, it increased. it would cost me 600. no way I'm getting it
Zener diode perhaps?
@@joveaaron-real go check for a pokit meter I can be a good alternative
You can sometimes get an old analog scope for pretty cheap compared to a brand new digital one. Granted, they have nowhere near as many features as the new ones, but if your personal work or hobby really only requires basic measuring of voltages over time, it might be more cost-effective. Some places that would be good to search for one would be university surplus stores (particularly if the university has engineering or physics departments) or electronics recycler stores, and maybe you'll get really lucky like me and find a garage sale selling ancient scopes for $20 a piece lol.
U coukd also use a flywheel diode.
1. Talks calmly
2. Reviews the product
3. Tells us the problem and doesn't get angry even tho he'd had any right to
4. Calmly gives the easy solution to the problem
Sir, you dropped this: 👑
Dude, you just described the whole point of Electroboom's channel existence.😂
@@excentrisitet7922 Thanks for sharing! I'll check him out!
@@excentrisitet7922not for the first and third point about anger💀
@@mamadzThat's what makes him entertaining, and when he zaps his fingers.
5. Who cares
I bet that the designer included a cap, and the test model he received had those caps. However, the producer simply left it out after getting the green light, and safe some money so he get more profit. This is a very common practice in some countries, and we all know which country it is. ;)
I won't be surprised if that's what really happened
Well, what country is it???
@@Ryroechina
Capitalism
@@GWT1m0communism
These used to be popular for iPhones many years ago, but this exact issue would kill your usb port, always wondered why, now i know, thank you!
I think I saw that on TechSmart
they're making a comeback as promo items! 😯
Whoever made this fan, I can guarantee you that not only are they not watching this, but they are also perfectly aware of both the spikes and the fact they can be fixed by a capacitor. That $0.1 really adds up when you push 100000 of these wholesale to people who _really_ don't care what they're reselling.
All the DC motors I ever salvaged had a small orange capacitor in between the terminals, surprised this one doesn't have it.
Funny part is i always thought that was just a tiny starting cap, now i know better
@@johnfeistner467 It's a ceramic capacitor that suppresses the interference caused by the brushes. I've seen universal motors that have it too, because back in the day the interference would produce static lines on old analog TVs.
@@enzoperrucciofunny
They skipped this 1 cent part and pocketed the money, I'm pretty sure the designer included the cap, but the factory in china dropped it from production to increase their bottom line.
Holy sh!t! So that was the main culprit! Back in 2022, we had frequent load shedding and it was summer and so hot... I made a simple DC motor fan and used to plug in to the USB port of my laptop. After 2-3 weeks, my all the usb ports were gone forever and I couldn't even connect my mouse or mobile to transfer data... I wish I knew this before...
Same happend to me too
i have this exact fan shown on the video and it froze my pc when i plugged it in, only really good if its on a power bank
@@TabbyEgg312 it's not good for powerbanks either because it can easily fry the converter board
mmm, i did use a similar fan on my now death laptop, weird that i didn't use it for a year and still worked tho before its death.
Poo 💩
i finally see a practical reason to have a cap between positive and negative
Capacitors are actually used in a lot of standard circuits in that way, they are irreplaceable in AC to DC converters of any kind to smooth out the small waves of the rectifier to an actual DC current. They are also very important in filtering out voltage spikes, and can lower the neccesary energy to power inductive loads like motors by negating the induction currents in the cables with their capacitance, they basically take what the induction pushes back into the conductors on the rising wave in AC current and feed it back on the falling wave. That way the actual current flowing through the conductors is reduced which saves on materials and reduces the energy loss caused by the high currents in uncompensated motors.
so wud this make a motor more efficient using a modified sine wave from a cheap inverter(12vDC to 110vAC)? @-sturmfalke-
@@Eduardo_Espinoza Yes, somewhat. Jt is important to remember that it is not the efficiency of the motor that is being improved, but the energy loss over the length of the cable that leads to it.
Basics of electricity:
Every conductor has a resistance. If there is a voltage difference between both sides of an conductor, current flows, the higher the voltage the higher is the current. Resistance slows down the flow of current, the higher the resistance, the more it is slowed down, the energy taken away is transferred into heat. A bad conductive material or thinner wires have a greater resistance than their opposites.
Basics of coils:
If current flows through a copper coil, a magnetic field is created inside of it. When the current is rising, the resistance of the coil is low at first, but increases exponentially with the time, as it is saturating the magnetic field. When the current stops flowing, the resictance and magnetic field decrease exponentially. I would recommend looking up the graphs for visualization. When stopping the flow of current rapidly, an even greater current is being repelled backwards through the wires for a short time, which can potentially damage electronics, there a multiple methods of avoiding that, for example special diodes.
Basics of capacitors:
The effect of the capacitor is the opposite.
When a voltage difference is applied at the two poles of an capacitor, it has a low resistance at first, increasing negatively exponentially, the current on this pole is therefore decreasing exponentially. When the limit of the storeable energy is reached, the flow of current stops. Then there is a voltage difference between the poles. When both poles are connected, a current flows, discharging the capacitor. In the beginning, the current is very high, as the voltage is able to overcome the resistance between the poles, but as the voltage decreases, so is the current, which happens negatively exponentially. For visualization, I recommend looking up this graph too.
Compensation:
When you now connect a coil with a capacitor in parallel, the coil being the motor, for 3-phase current you need 3 capacitors, the current repelled by the coil is being pushed into the capacitor, which stores it at feeds it back into the coil in the next cycle. If you don't use a capacitor in parallel with the motor, this current is being pushed back into the wires, eventually loosing its energy in the resistance, but the motor draws a lot of current in the next cycle from the grid. Because you have such big operating current, you have to increase the diameter of the wire, to keep resistance low enough to not loose too much energy in heat. It also increases the load on the grid and the energy usage recorded by a power meter.
Real-World application:
In reality, only bigger motors are built to compensate the current, I have not heard of handheld devices that do that yet, since the losses are usually neglectable in that scale. As a normal consumer, this is usually not something to worry about at all.
Disclaimer:
I have to inform you that the wording of these explainations is by me, I have not used any sources, and might have made mistakes. I'm not a teacher in electronics, and just finished my electronics studentship. English is only my secondary language.
lessons learned:
1. USB is not as universal as it's name says
2. every DC motor needs a capacitor to prevent voltage spikes
Well it's Universal Serial Bus (data transfer) not "UPS" Universal Power Supply.
@@cf8wuf98w4lu AC motors ussually don't have a comutator(fast switch that causes those voltage spikes) so it would work, even without capacitor. However USB has DC voltage, not AC
Also how about adding a diode to prevent back EMF?
I directly wired up a usb to a motor with a propeller and it killed all the portable usb batteries I plugged it into. I even plugged it into Laptop but the laptop cut it off. This video was very helpful. won't do that again
Not an expert, but one of the things a motor driver will do is suppress the spikes, back EMF, etc. You can get a single IC that will do the job.
From a nontechnical POV if you do something and it suddenly gets wrong and you don't know what it is, you probably shouldn't do it again
@@phucminhnguyenle250 no i just used other battery banks before the other ones died
I PLUGGED ONE ONCE ONTO MY LAPTOP. IT GAVE ME A BSOD. NO JOKE. IM LUCKY THAT IT STILL WORKS.
A BSOD isn’t something that can kill your device. It’s, in fact, a way to prevent data corruption - it happens right before something is about to go seriously wrong.
WHY ARE YOU SCREAMING?
@@darkhippo6222BECAUSE HIS COMPUTER ALMOST BLEW UP
Onde i testes if i could charge the laptop trought the USB C using a phone charger, laptop turned screen of for a second and continue working, i havent seen anything different on my laptop and the port still works
I'm so proud that i have no idea about electronics but still came up with the capacitor idea as well
Unfortunately, it's not the correct solution.
@@AureliusR damn really?
edit: didn't he even show that it works?
@@AureliusR its definitely the correct solution
@@justinc2633 No, it's not. A freewheeling diode is the correct solution. Putting a capacitor there, especially electrolytic, will lead to failure of the cap as it's having to absorb all those high voltage spikes. It's better to simply snub them with a diode.
@@AureliusR that is genius, the excessive voltage will return back into the battery without shorting the circuit
You could alternatively use a flyback diode, negatively biased in parallel to the inductor. That way you would prevent any parasitic LC oscillation.
This is the only way. Using a capacitor severely reverse biases it, probably eventually destroying it.
You didn’t just help consumers avoid a bad product but you offered solutions to the designer 👍🏻
Man, these capacitors are crazy
Back in my days at engineering school , I made that tiny robotic arm.. It worked but I remember the movement was flimsy and that bothered me a lot , one capacitor hooked to the output fixed the issue.
And since that was something our professor somehow forgot to teach us during the semester, he loved it so much that he juat gave me the full mark without going through the marking process guide 😂
That Spike's are probably Back EMF, if you say you will put a capacitor then i would recommend a free wheeling diode.
Probably should use a zener or tvs, that way it’s protected in both voltage directions as well as providing a path for the inductance to gracefully spool down.
@@hugegamer5988TVS won’t work because it will just short out? Oh no, I guess it’s fine as long as your TVS voltage is higher then the supply voltage
@@albertogregory9678 yes, that precisely the purpose, to short out transients, during the conduction period the voltage drop stays above the stated threshold, it’s similar to a zener diode reverse biased.
Thank you, someone else knows about flyback diodes
Watching a capacitor eliminate those voltage spikes is so satisfying
i thought it would lower the back-emf spike, not completely eliminate them, very cool
Would a resistor work too?
@@maxiliarydendrite8926 a resistor in series with the motor? it wouldnt prevent a spike, maybe the amplitude of it tho. but your motor will also not spin as fast due to the voltage drop across the resistor. if you mean in parrallel with the motor, that wouldnt really do anything. your best bet is a capacitor and a diode for protecting against back emf
If you are Electroboom fan, its not
But a capacitor would cost them an extra 3 cents! Won’t someone think of the garbage manufacturers?!
W for this man giving the manufacturer an advice
I always think something is off if you put anything in usb port beside mouse, keyboard and flashdrive but i can't think how, this short enlighted me
You can turn any pc case fan into a usb. Much better than whatever this is.
How do I know it won't cause the same issue? I've been thinking of doing it for a while
@@Sapple498it's specifically designed for a pc, unlike this one which probably is just your regular dc motor plugged into an usb cable
@@therealtdp That's a good point. I actually did it a few hours ago: now I have a USB powered tower cooler I have no use for :)
@@Sapple498 maybe on a hot day, using an OTG converter, you can convert it as a fan using your phone.
But a case fan is 12v and USB is 5v.
Very informative. Thanks for sharing
Not only is that an inductive load but it's probably a brushed motor which means the current through the coil is interupted very quickly causing these huge voltage spikes.
Industrial factories that have lots of motors will have a capacitor bank to balance the inductive load. This will lower the electricity bill.
Science ! Salut ! To your findings.
shouldve suggested me earlier😅
The your oscilloscope was about to have a stroke reading that
A flyback diode clamps the spikes. You could add a soft start capacitor too.
Fun fact, this is very similar to why your home air conditioning has a capacitor for the fan and compressor. It also has the added benefit of being able to use that back emf as a third phase making the motor more efficient and extending the life of the motor.
Interesting, but more interesting is why adding the capacitor helps so much, can you expand on that?
That’s why you find those capacitors across the terminals, so that’s why to reduce voltage spikes I’ve wondered why they were there
Wow, ive been studying how transformers and power supply's work at my school, adding that capacitor makes a lot of sense. Never thought i was going to see a practical example of it so quickly lol
Thanks for telling us what the actual product is
USB fan? What a terrible, terrible idea. This is the Darwin Award of hardware.
Filter capacitor and a reverse biased rectifier will help a lot.
Or add a free wheeling diode
put your hands in it (recommended)
Actually, the blades are made of something like soft foam. It really doesn't hurt
put your willy
@@LeftyMakercool
@@LeftyMaker try using peepee then
Well done Maker Channel. I enjoy your advise👌
I'm fairly certain that the identical looking fan that i bought at a legitimate electronics store some 20 years ago included back feed suppression and noise filtering. But then it got simplified for cost for less sensitive markets. I'm sure they know how to build it properly and why, your seller merely didn't deem it budget worthy.
Did the power supply knob work again after unplugging or did it fry something?
Hope do notice me anyway what do you mean?
@@AngeloLuis22 typo. I meant "did it fry something"
It'll have been okay after the unplug, the knob that stopped working was the voltage control
It's fine. The knob wasn't physically broken, the voltage spikes just "confused" the power supply.
Call'em out. Ledgend!
What about a CPU fan to USB? I do that sometimes 😅
CPU fans that are worth half a (insert cheap thing here) come with capacitor/diodes in them. It should be fine.
@@phillyphakename1255 And they're brushless so they're very quiet and don't use nearly as much power
How does a 12V CPU fan work off a 5 volt USB port?
@@Wingedmechanic it will run...
Just not nearly fast enough lol
@@Wingedmechanic It works great. It runs nice and quiet. If you put 12V into it, it will be max speed and loud -- I don't need that much air lol
Yup, happened to one of my USB ports. Wish i knew this sooner 😅
Ahhh, so that’s why I see tiny SMD capacitors on lots of motors I extract from RC cars and some other stuff.
after not adding the cap, do not trace soft blade into a piece of pop can and installing it making it workd better but less safe...
A diode across the motor terminals wired properly works to .
You are right! I bought a regular 5v motor and connected it to a usb cable (the usb cable end was torn so I cut the end open and connected red and black wire to motor) and then plugged it to my charger, soon the motor starts to slow down and when I touched the charger, it heated up in 5 seconds and stopped working.
"Boss, we have all those USB Killers, what do we do with them?"
"Stick a motor on top"
"What?"
"You deaf? Stick a motor on top. GTFO my office."
Thanks for this information!
So it was just the motor? No diodes, no capacitor, just the motor?😂😂😂
Someone at the office had one of these till the IT guy came and yeeted into the trashcan
This information saved my life
Thank you for the knowledge
God bless your year
Nice find 👍 speaking of fan, I once connected a dimmer to a big desktop fan to regulate its speed. The fan motor became very hot and stopped working 🙄 Could you explain what happened?
I was using two of those, one with the power bank, another with laptop.
But mine could be with capacitors.
So if i get one, i can simply add a capacitor and it would be fine to use? Minus the vibrations, i mean.
All I heard was "the perfect gift for your in-laws"
Subscribed. Keep on teaching people stuff.
i've been using the same usb fan for the last 8 years, let me check it with an oscilloscope. thanks for the information
Oh thanks for telling us which fan it is
Thats why my usb ports are so wonky-
Bro sounds like Nuclear Nadal 💀
What about those usb desk fans? 🤣
so proud i’m learning i actually knew the problem and the solution this time. i just can’t believe they didn’t for one second plug this thing into an oscilloscope or power supply and realise their mistake. i can’t think that it was intentional, all to save a couple cents.
Also, add a diode in reverse bias
I have always felt that these things are unsafe now i know why.
What about an induction charger?
cheap battery toys: CAPS PUT ALL THE CAPS TO ALL THE MOTORS !!!
USB device: NAH, DONT WANA
I gotta know the answer, i have this exact fan and ive been using it last summer, i connected it to my pc (not laptop). What have it done to my pc D: ?
Glad my old job handed these (with a cheap rgb display on the blades) out instead of bonuses. Im sure the replacement motherboards will still be less money than it costs to pay people what they're worth.
I use something like this as a digital nomad living in Central America. I never plug it into my laptop. I always just carry a power bank and plug it in there
All it needs is an RC snubber across the rails but I suppose that would have added three cents to the manufacturing cost so it was omitted.
Didnt just critique but gave a solution..now thats a rare one folks 👍🏼
I prefer a reverse diode over the capacitor.
I guess the most important reason is, that they just make noice and they don't shovel air😂
I have one of those and used it in my laptop usb and it got messed up. Its still working fine but i can hear my mouse connect and disconnect randomly.from time to time. Luckly the damage is very minimal but definetly dont use this in any main usb port. Its fine if u have like an old phone charger so it doesnt matter if it breaks. Also the blades are soft you can put ur finger in them while theyre spinning and youll be fine.
Bro fixed the product too 😭
They ALWAYS seemed fishy to me. Thanks for using science to show why!
ah so that were the capacitors on the motors for.. i used to cut them off all the time because i thought they made the motor slower.. the more you know
How does a parallel capacitor remove the voltage spikes? Wouldn’t that just create an LC oscillator? Pls help I’m confuzed
Hm you can put some diode connect backward for remove 20volt spike
Ive actually seen quite a few capacitors on motors in items ive taken apart. I wasn't sure what they were when i was younger tho
I built one of those and pluged it in my computer and it worked perfectly
Capacitor for smooting and a diode against back emf would help
i had one of these for my ipad when i was younger, i had it plugged in for a while and it completely bricked the ipad
I had one when I was younger and it actually tripped my PC's electric safety shutdown. I couldn't boot it and finaly figured out it was overdrawing the voltage on my front panel.
Booted fine after that, but fuck that shit
Ceo of manufacturer: dude do you have any idea how much more money i make by not paying for nor paying someone to add a capacitor to each of these!?
Wait, Capacitors do not short circuits?
I have little understanding of tiny motors and batteries from Tamiya days. 😂
Noted. Thanks 😅
very useful video thanks.
Very educative ❤ thank you
I remember my mom picked up one of the little fans that plugs into your phone. Bricked her then-new phone.
Could you also just use a diode across the positive lead?
This could potentially be useful as a kill drive where the goal is to *intentially* kill the USB port/device lol
Can we plug usb Led to our laptops???
what should be the value and raring if the capacitor?
That is why DC Motors typically have a rectifier diode across The leads of the motor to prevent this back EMF ( Electromagnetic flux) .From damaging components.
Even the cheapest of the cheap Chinese cars I purchased had the same motor with ceramic cap , don't know what these people were thinking 😂
Do laptop cooling pads have the same issue?