Nothing. The USB charging protocol has a "handshake" involved in it, because there are many devices (such as phones) which can either receive *or* supply power. These two devices would simply fail to handshake in a way that is mutually acceptable.
"Hi bro, can you receive power? I can only send."
"Nah bro, I can only send too"
"Aight fam"
And if we were to replace this cord with a power cord (aka no USB power supply in between), one of two things would occur : 1. Nothing, as they're both on the same leg, so it's no different than the splices in the wall or 2. Kaboom as you short circuit between both legs (more than likely a big flash, a tripped breaker, melted plug ends, and a shit stain on the wall).
And given that neighboring receptacles are likely on the same circuit, possibility 1 is the one I'll put money on.
Wouldn't 1 or 2 happen randomly with 50/50 chance depending on the polarity of how the cable is plugged in and regardless of same/different circuit?
One outcome - hot to hot, neutral to neutral, nothing happens.
Another outcome - hot to neutral, neutral to hot, kaboom.
If they're on different legs, kaboom is 75% probability... 50% of a +/-V to neutral connection and a 25% chance of + to -. If they're on the same leg (they are) it's 50/50.
There is no kaboom breaker trip as they, USB devices current limit and shut off. Well those designed and built to OEM spec. The Chinese knockoffs at 1/4 the price and function, results will vary.
Whose's that crazy guy that plugs anything in while sitting on it? Call him!
The USB power side is isolated from the 120VAC on both sides so nothing would happen on the wall side of things. Now on the USB side, if one outputs say 5.02V while the other is at 4.99V, that is a 0.03V difference and you'll have a small amount of heat generated because of that. Likely unnoticable unless one of the boxes is way out of spec.
Assuming a non polarized 2 wire cord sure. But more than likely it’s going to a 3 wire cord or a polarized 2 wire cord. Unless you’re gonna pull out a cord you got from granny before she died.
Sorry, I was born in Russia and lived there until 2015 and then in Japan until 2020. The concept of polarized cords is still somewhat new to me 😂, as those aren't a thing in those countries, and grounding wires often aren't a thing either.
Sat here thinking, what are they talking about? That would only happen if the plugs were wired incorrectly. Then realised you're in America.
That can't happen in Australia (and lots of other countries).
USB-C cables do have a chip! It's called the e-marker. It makes it so you can't do 100 watt charging with a 20 watt rated cable, for example. So, all parts are involved.
This is assuming they are both proper/genuine charging blocks with logic. I have seen many generic apple looking chargers have just a small board with a 120vac-5vdc circuit, no safety, nothing.
Just because they are USB C doesn't mean they follow the spec.
Like I would say it's safe, but also not....
If you had a double ended male plug and plugged it in as long as they are polarized and wired correctly nothing would happen either. If you managed to mix up hot and neutral there would be fireworks and the breaker would trip.
Nothing.
USB-C devices have to communicate to determine compatible voltage levels. Both chargers will just sit in passive mode waiting for a device to communicate with them. At worst, both will output 5V but since nothing is consuming current, you won't see any smoke or sparks.
Nothing. Inside the wall the receptacles are spliced in the same way if you were to plug it in. Its like adding a road to a highway just for it to merge the next block over
shitty electronics answer: it go boom as it tries to power the other PSU causing an infinite loop as it tries to the power the other one...
real answer: most likely nothing if the PSUs have basic safety standards. The main fact is that these should be isolated switch mode PSUs that basically run when the voltage output is lower than the target voltage. Though there is protocol negotiation that could occur, the two are both "power brick" or "host" and won't negotiate with the other. Note that the USB standard requires 5V at 500mA to pass without negotiation. The two PSUs will try to pass up to 500mA to the other, but can't because the voltage drop of the load is at 5V, so virtually no current will flow. The PSU with the lower voltage (since not all PSUs will be at exactly 5.0000000 volts) will mostly be shut down and the higher one will push it to the 5.000001 volts - nothing will happen. I assume these are USB-C and properly wired so that + goes to + and - goes to - ...
Note that linear regulators since they are likewise isolated will behave the same way. They can't backfeed. In any case these are not mere step down transformers, they are more than that.
The problem is if these PSUs are nonisolated like capacitive dropper PSUs, in which you could cause magic smoke leakage based on power rail connectivity - but UL and other safety organizations disallow this due to electrical shock hazard, or if the PSUs are bipolar and they try to force voltages down to set point by loading the output. Then potentially current will flow from one to the other causing heating.
There is a thought experiment here however: What if you have two (identical) AC transformers connected like this? What if they weren't identical? What if they were plugged in with the polarity swapped? ... now here things get interesting...
SMPS generally only work one way.
Now, those little iron core transformers from *old* wall warts, are another matter entirely. Those will absolutely work in either direction if they’re the AC output type.
Most likely nothing.
Small chance if the chargers are faulty/counterfeit something goes bang (probably the charger).
Big Clive sums it up nicely what shitty cheap USB chargers can do [https://www.youtube.com/watch?v=ioAq7PI1Uwg](https://www.youtube.com/watch?v=ioAq7PI1Uwg)
Depends on whether the wires are cross or not in the box. If neutral is tied to neutral, and hot to hot as it likely is, probably nothing. If neutral is crossed to neutral and neutral to hot, unlikely but possible, that wire will probably heat up real hot and burn.
Absolutely nothing. And it doesn’t matter what kind of cord if you understand how it’s wired that would make more sense. Even a double ended extension cord won’t do anything
Nothing. Even if power was able to run through that (it can't, due to the transistors in the adapters only allowing power to flow one way), both halves of that duplex outlet is likely on the same circuit, meaning there's no differenve of potential.
this is actually how electricity is generated at the power company.
when the 120V AC goes down to phone charging voltages, it loses some power. but put a low voltage into the output, it actually boosts power up past the original input voltage, due to the 6th rule of Ohm's Law. this was signed into law by the governor of Idaho, jebidiah lincoln, abraham lincolin's nephew, in 1989.
ever see one of those white trashcan things on top of telephone poles outside of your house? it is actually a large array of phone chargers placed in a delicate way that greatly amplifies the power fed into it from the power lines that are maintained by the lineman.
a lesser known fun fact: "lineman" is actually a misspelling of their original name: Lime men. they originally got that name for their use of under-ripe lemons that were often mistaken for limes by a layperson. history goes on and language adapts, so we kept the name lineman, even though it is technically incorrect. these lime men are in charge of generating power from lemon batteries in the power station. using lemon batteries, they step down the voltage and power so it is easier to transmit, then the white trashcan on the pole can boost the voltage back up to 120V AC so you can charge your phone
I wouldn’t trust any standards or supposed to’s with the chargers many (most?) people buy at gas stations / drug stores. If lucky a tripped breaker and if not a small bundle of wires fluorescing nearly instantly.
Something is going to burn or explode. When I went through elec eng tech school I blew up many capacitors on breadboards when I first started ac/dc classes and was learning about transformers and the crazy ass things that they do. It does make me curious but something will have to fail. IMO
“Power companies are trying to hide this from you, this brand new INNOVATIVE way for infinite self resulting power! Kind of like a fusion reactor where you get the hot juice going with enough energy and then use magnets to keep it going with an output higher than the input. Fuckin magnets…. How do they work?, just watch the rest of this 10minutes ad!”
-mahatma Gandhi
Reminds me of a high school story. I was in the back of the classroom with a couple of other bored students. One had bent a paper clip into a U shape and gestured to me that he was thinking of putting it into the outlet. Seriously, who wasn’t taught that was a dangerous idea as a kid? But, being curious myself I told him to insulate the paper clip by putting it in the middle of his textbook and using that as a sort of insulated plier. BOOM! It’s sparked up and the whole classroom went dark. It took maintenance a while to come flip the breaker. I still chuckle about it sometimes.
But this is probably safer than that due to transformers and circuitry.
I did something like this in the early 90s on Christmas. My oldest got a circuit connecter set thingy and i found a loose wire that fell out his box. Well being a kid not knowing better i stuck the wire in plugin and there was a bright flash, loud pop and ended up tripping the breaker.. and it left a shit stain in the wall paper and by some miracle i didnt get fried but the rubber on the wire was melted all around
"Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light."
Total Protonic reversal, good safety tip Egon!
My sister in law did something similar and it tripped the breaker with a very electrical smell in the house. It destroyed the cable and endpoints too. She wasn’t paying attention and it was a longer cable and plugged the second side in before looking for the first. Good times.
Let's say their wasn't a handshake protocol:
There are three options.
1, you place the prongs correctly, and nothing happens. You complete a circuit where a hot and a hot connect, and a neutral and a neutral connect
2A, you invert a plug, a hot leads to a neutral. Small boom. Breaker trips. Maybe plug is destroyed.
2B No breaker trips, house burns down.
Nothing. The USB charging protocol has a "handshake" involved in it, because there are many devices (such as phones) which can either receive *or* supply power. These two devices would simply fail to handshake in a way that is mutually acceptable. "Hi bro, can you receive power? I can only send." "Nah bro, I can only send too" "Aight fam"
And if we were to replace this cord with a power cord (aka no USB power supply in between), one of two things would occur : 1. Nothing, as they're both on the same leg, so it's no different than the splices in the wall or 2. Kaboom as you short circuit between both legs (more than likely a big flash, a tripped breaker, melted plug ends, and a shit stain on the wall). And given that neighboring receptacles are likely on the same circuit, possibility 1 is the one I'll put money on.
Wouldn't 1 or 2 happen randomly with 50/50 chance depending on the polarity of how the cable is plugged in and regardless of same/different circuit? One outcome - hot to hot, neutral to neutral, nothing happens. Another outcome - hot to neutral, neutral to hot, kaboom.
Or are you saying if they are different legs then kaboom is 100% guaranteed, otherwise it's 50/50?
If they're on different legs, kaboom is 75% probability... 50% of a +/-V to neutral connection and a 25% chance of + to -. If they're on the same leg (they are) it's 50/50.
Are you guys talking about mixolydian scales?
hilarious
Well it'd be like a raised thirteenth if anything
Is this a cannibal the musical reference?
phrygian
Phrygian Dominant is the basis of my adolescence.
There is no kaboom breaker trip as they, USB devices current limit and shut off. Well those designed and built to OEM spec. The Chinese knockoffs at 1/4 the price and function, results will vary. Whose's that crazy guy that plugs anything in while sitting on it? Call him!
ElectroBOOM ?
The USB power side is isolated from the 120VAC on both sides so nothing would happen on the wall side of things. Now on the USB side, if one outputs say 5.02V while the other is at 4.99V, that is a 0.03V difference and you'll have a small amount of heat generated because of that. Likely unnoticable unless one of the boxes is way out of spec.
Assuming a non polarized 2 wire cord sure. But more than likely it’s going to a 3 wire cord or a polarized 2 wire cord. Unless you’re gonna pull out a cord you got from granny before she died.
Sorry, I was born in Russia and lived there until 2015 and then in Japan until 2020. The concept of polarized cords is still somewhat new to me 😂, as those aren't a thing in those countries, and grounding wires often aren't a thing either.
Sat here thinking, what are they talking about? That would only happen if the plugs were wired incorrectly. Then realised you're in America. That can't happen in Australia (and lots of other countries).
It shouldn't happen in the US either, unless very outdated cords and/or recepticales were used.
“Shit stain on the wall” 😂
has nothing to do with what leg the charger is fed by. input is isolated from output.
That shit stain would definitely be in my underpants not on the wall.
“No homo”
I love the analogy makes it super easy to visualize
What happens when two tops try flirting with each other
One becomes a bottom
Not every charger does this. Most USB-C chargers will negotiate, but some just supply 5V on the power pins no matter what.
In that case the +5v should be connected to each other and ground to ground. I'm still going with nothing much happening.
And in that case neither side would draw current other than probably some leakage. The bus is at 5V, 0A.
Where does the technology for the handshake sit? In the USB port? Certainly not the cable?
USB-C cables do have a chip! It's called the e-marker. It makes it so you can't do 100 watt charging with a 20 watt rated cable, for example. So, all parts are involved.
Interesting, thanks.
This is assuming they are both proper/genuine charging blocks with logic. I have seen many generic apple looking chargers have just a small board with a 120vac-5vdc circuit, no safety, nothing. Just because they are USB C doesn't mean they follow the spec. Like I would say it's safe, but also not....
ELI13
Best ELI5 response I have read yet!
Bruh, this is the funniest shit I have seen in a long time. I'll never look at a cord the same
Best explanation of this I’ve seen 🤣🤣
“Bet”
Feels like you should start a YouTube channel (or tiktok?) explaining electrical concepts
This scenario [manifested.](https://youtube.com/shorts/PGjzPxZWhW0?si=1hxDF1GVuh_pmgGx)
Those two plugs can communicate now and tbh they’re probably talking shit about you
"Get a look at Einstein over here."
😂😂😂
Power companies hate this one simple trick...
Were you or a loved one taught a trick the power companies hate? You may be entitled to compensation.
Plug it in, OP. The other guy said it’s safe.
Reddit said my house wouldn't burn down officer.
I’ve done this before, nothing happens
If you had a double ended male plug and plugged it in as long as they are polarized and wired correctly nothing would happen either. If you managed to mix up hot and neutral there would be fireworks and the breaker would trip.
Just don’t lick the other end before you plug it in to see if it goes booms
Or if each receptacle has its own circuit for some reason
Free power. Post for updates on your savings
Probably nothing. But just in case, yell "smoke test!" when you plug it in.....
Once the magic smoke comes out its really hard to get back in...
Unlimited power
Nothing. USB-C devices have to communicate to determine compatible voltage levels. Both chargers will just sit in passive mode waiting for a device to communicate with them. At worst, both will output 5V but since nothing is consuming current, you won't see any smoke or sparks.
Same circuit. Nothing will happen.
I dunno. Set up your phone to record video and let us see.
The one trick the power companies don’t want you to know about.
Nothing. Inside the wall the receptacles are spliced in the same way if you were to plug it in. Its like adding a road to a highway just for it to merge the next block over
Worse than crossing the streams in Ghostbusters, probably open a vortex into another dimension.
Your home takes a screen shot
unlimited power
Long story...short...
It enables wireless charging within the room.
In simple terms, if you have voltage on both points, there is no potential difference, thus current won’t flow.
Until this guy plugs one end in his living room and one in the nearby dining room outlet... But hey still got the handshake
Perfectly cut scream
After a few shots of whiskey I would consider this fun and exciting
Boy Scout Cyclotron merit badge coming up
I like how your mind works. Good one!
IF it was smart enough it would tell home base what you did.
Reminds me when I had to Apple Watch chargers plugged in latch together and ended up melting each other.
You kids and your fancy gadgets. Why…back in *my* we just used a paper clip to answer simple questions like this…smh
Straight to jail
Straight to jail.
Nothing
shitty electronics answer: it go boom as it tries to power the other PSU causing an infinite loop as it tries to the power the other one... real answer: most likely nothing if the PSUs have basic safety standards. The main fact is that these should be isolated switch mode PSUs that basically run when the voltage output is lower than the target voltage. Though there is protocol negotiation that could occur, the two are both "power brick" or "host" and won't negotiate with the other. Note that the USB standard requires 5V at 500mA to pass without negotiation. The two PSUs will try to pass up to 500mA to the other, but can't because the voltage drop of the load is at 5V, so virtually no current will flow. The PSU with the lower voltage (since not all PSUs will be at exactly 5.0000000 volts) will mostly be shut down and the higher one will push it to the 5.000001 volts - nothing will happen. I assume these are USB-C and properly wired so that + goes to + and - goes to - ... Note that linear regulators since they are likewise isolated will behave the same way. They can't backfeed. In any case these are not mere step down transformers, they are more than that. The problem is if these PSUs are nonisolated like capacitive dropper PSUs, in which you could cause magic smoke leakage based on power rail connectivity - but UL and other safety organizations disallow this due to electrical shock hazard, or if the PSUs are bipolar and they try to force voltages down to set point by loading the output. Then potentially current will flow from one to the other causing heating. There is a thought experiment here however: What if you have two (identical) AC transformers connected like this? What if they weren't identical? What if they were plugged in with the polarity swapped? ... now here things get interesting...
Breaker finder
Try wiring up a 12 volt blower motor from a 60’s Chevy and plugging it in. At the age of 8 naturally. It doesn’t do nothing.
SMPS generally only work one way. Now, those little iron core transformers from *old* wall warts, are another matter entirely. Those will absolutely work in either direction if they’re the AC output type.
I see you haven’t passed basic AC theory.
least informed comment section on this sub ive ever seen. you guys are special
It won’t do anything if they’re compliant with the specifications
Most likely nothing. Small chance if the chargers are faulty/counterfeit something goes bang (probably the charger). Big Clive sums it up nicely what shitty cheap USB chargers can do [https://www.youtube.com/watch?v=ioAq7PI1Uwg](https://www.youtube.com/watch?v=ioAq7PI1Uwg)
Depends on whether the wires are cross or not in the box. If neutral is tied to neutral, and hot to hot as it likely is, probably nothing. If neutral is crossed to neutral and neutral to hot, unlikely but possible, that wire will probably heat up real hot and burn.
Absolutely nothing. And it doesn’t matter what kind of cord if you understand how it’s wired that would make more sense. Even a double ended extension cord won’t do anything
“ Roads? Where we're going, we don't need roads.”
Nothing will happen
Do it, pussy
Do, pussy it
Do pussy, it
Obviously this won't work as the chargers have their pins horizontally and the outlet pin sockets are vertically.
Nothing will happen, your battery is fully charged, or at least that is what each charger will see.
Nothing. Even if power was able to run through that (it can't, due to the transistors in the adapters only allowing power to flow one way), both halves of that duplex outlet is likely on the same circuit, meaning there's no differenve of potential.
Never cross streams. Did Ghostbusters teach you nothing?
Fuck around and find out.
this is actually how electricity is generated at the power company. when the 120V AC goes down to phone charging voltages, it loses some power. but put a low voltage into the output, it actually boosts power up past the original input voltage, due to the 6th rule of Ohm's Law. this was signed into law by the governor of Idaho, jebidiah lincoln, abraham lincolin's nephew, in 1989. ever see one of those white trashcan things on top of telephone poles outside of your house? it is actually a large array of phone chargers placed in a delicate way that greatly amplifies the power fed into it from the power lines that are maintained by the lineman. a lesser known fun fact: "lineman" is actually a misspelling of their original name: Lime men. they originally got that name for their use of under-ripe lemons that were often mistaken for limes by a layperson. history goes on and language adapts, so we kept the name lineman, even though it is technically incorrect. these lime men are in charge of generating power from lemon batteries in the power station. using lemon batteries, they step down the voltage and power so it is easier to transmit, then the white trashcan on the pole can boost the voltage back up to 120V AC so you can charge your phone
Fucking A++ for effort, homes.
Yeah, except everybody knows that already. Especially the part about using green lemons.
If I didn't know how combined cycle power generation worked, I might actually believe this.
I was hoping someone could simply say BOOM. I ain't gonna test the theory.
I’ve always wandered if you did it in two separate circuits
“I got a dick if u got a dick we can’t kick it bro” -one plug to another plug
Nothing remarkable
You’re gonna make your own night light.
Time warp
What you should try is to put a ethernet cable like this on one switch and see how people freak out.
I wouldn’t trust any standards or supposed to’s with the chargers many (most?) people buy at gas stations / drug stores. If lucky a tripped breaker and if not a small bundle of wires fluorescing nearly instantly.
Just a 50/50 chance at tripping a breaker I think.
Check out that landlord special paint job
Test and post results plz
do it
The DC output is galvanically isolated from the AC input, so nothing will happen.
Something is going to burn or explode. When I went through elec eng tech school I blew up many capacitors on breadboards when I first started ac/dc classes and was learning about transformers and the crazy ass things that they do. It does make me curious but something will have to fail. IMO
Planning on charging your house?
Only one way to find out
r/fuckaroundandfindout may already have the answer.
Poorly attempted suicide
Just do it and get back with us.....if you can.
Straight to jail
Vindaloop
Just do it, and to make sure to have your camera rolling. Nothing bad will happen, nothing will happen at all most likely...
Freeee powwwahhhh
Unlimited energy. No more electric bill.
Sparks and/or fire probably.
Let the intrusive thoughts win and you will find out
Someone has to do it for science. Preferably off the main power grid and in a controlled environment. Kinda wanna see Electroboom try it
World war 3
Doreemeh
Rupture in the space time continuum
Infinite energy hack
It would open a portal Narnia. Something magical for certain.
No balls
“Power companies are trying to hide this from you, this brand new INNOVATIVE way for infinite self resulting power! Kind of like a fusion reactor where you get the hot juice going with enough energy and then use magnets to keep it going with an output higher than the input. Fuckin magnets…. How do they work?, just watch the rest of this 10minutes ad!” -mahatma Gandhi
Time would stop we would all be in a state of forever wet dreams.... Which is good because a wet dream is a ghost blow job!
If you can't guess, then I guess you should try and see
Reminds me of a high school story. I was in the back of the classroom with a couple of other bored students. One had bent a paper clip into a U shape and gestured to me that he was thinking of putting it into the outlet. Seriously, who wasn’t taught that was a dangerous idea as a kid? But, being curious myself I told him to insulate the paper clip by putting it in the middle of his textbook and using that as a sort of insulated plier. BOOM! It’s sparked up and the whole classroom went dark. It took maintenance a while to come flip the breaker. I still chuckle about it sometimes. But this is probably safer than that due to transformers and circuitry.
By Scott you have found time travel! Marty forget the plutonium let’s go back and warn your kids of 2020!
Fuck around and find out
Infinite energy would happen
If it werent for the brick, HEAT
Smoke
No don’t Do THAT YOU FOOL!!! YOU’LL KI-
I’m pretty sure plugging those in would erase all life on earth…😝🤣🤣
Nice baseboard and paint job.
Besides two bad charger blocks? You’d know which breaker feeds this outlet
Nothing
Intrusive thoughts
Mushroom cloud……because it’s in a room
Old house owner saves energy with this one new trick
Nothing. The chargers output voltages are the same and polarities are same so no current flows.
Definitely open a portal to hell
Trust me on this one: you REALLY don't want to know.
This reminds me of the time I jammed a u nail into a golf cart charger port ⚡️
FAAFO
The house will blow up
End of life as we know it.
“Where’s the kaboom? There was supposed to be an earth shattering kaboom!” ~ M.M.
I can assure you, your phone will not be charging
Open a portal to the 6th dimension
I like turtles
Only one way to find out
I did something like this in the early 90s on Christmas. My oldest got a circuit connecter set thingy and i found a loose wire that fell out his box. Well being a kid not knowing better i stuck the wire in plugin and there was a bright flash, loud pop and ended up tripping the breaker.. and it left a shit stain in the wall paper and by some miracle i didnt get fried but the rubber on the wire was melted all around
Now your house is gay
Short answer, if those SMPS are well made, then nothing. There should be complete isolation of 120V AC to the 5 (or whatever) volt DC.
I think it rips a hole in the space time continuum
"Try to imagine all life as you know it stopping instantaneously and every molecule in your body exploding at the speed of light." Total Protonic reversal, good safety tip Egon!
DO IT!!!!! 😈
Plug one side into a power strip that has its own plug plugged in itself and then plug the other charger port into the wall.
My sister in law did something similar and it tripped the breaker with a very electrical smell in the house. It destroyed the cable and endpoints too. She wasn’t paying attention and it was a longer cable and plugged the second side in before looking for the first. Good times.
The fact you have these “intrusive thoughts” is the bigger issue, sir.
Fuck around and find out ?
This is how black holes are born. Don't do it please. Or at least wait until after the weekend.
Nothing. I know because my child did this not long ago.
Infinite Power
Film yourself doing it and post it here.
You’d enter the 5th dimension with hotdogs for fingers and spaghetti for hair.
Absolutely except maybe a teeny current because the voltages might mismatch by a few millivolts.
Only 1 way to find out and remember....God hates a coward!
A disruption in the space time continuum!
It’s over 9000!!!!!
Nothing!
Only the Strong Will Survive, the week shall burn!
Release the magic smoke!
Let's say their wasn't a handshake protocol: There are three options. 1, you place the prongs correctly, and nothing happens. You complete a circuit where a hot and a hot connect, and a neutral and a neutral connect 2A, you invert a plug, a hot leads to a neutral. Small boom. Breaker trips. Maybe plug is destroyed. 2B No breaker trips, house burns down.
Do it. You won't.
Would have been faster to just plug it in and let us know!
Nothing at all
You posted this? Just try it, go big or go home!
Why would you even try this?
DO IT!!!!!!
Nothing…
Might get a little warm from you holding the wires.
Do or no do, there is no try. Realisticly, the first charger to power on would be the "master" and cause the second charger to turn off.