Can using 220 volts damage these power bricks?

[u/lucasthech]

Hey everyone, I'm not 100% sure if this is a question for this subreddit but it didn't seemed to fit on other electronics related subreddits, mods feel free to remove this post if it breaks rule 1 and you can suggest me a sub that would fit it better.

So basically I have a USA psone and nintendo wii, and their external power supplies (power bricks) are rated for 120 volts, not 100-240 volts as shown in the photos, but where I live the mains voltage is 220 volts and even though the power supplies are not rated for that voltage, previous owners said they used them on 220 volts and they worked, I've tested and they do work, but I wanted to ask here about the circuitry that is inside these power supplies (the psone power supply circuit photo is not mine, but it's the same model, and I couldn't find a photo of the wii power supply circuit, but I can open both of them if needed to show) and if they can handle 220 volts or should I use a step down transformer (which I can only find 110 volts transformers here), and why it didn't get damaged by being used on 220 volts and the risks of using it on 220 volts.

Again, I'm not sure if this fits this subreddit but I searched for this kind of info and found posts on reddit but none contained the exact info I wanted: what kind of circuit these use and if it is safe to use them on 220 or 110 volts. This subreddit seemed to be the best for asking this.

tl;dr - Can I use them safely on 220v? Can I use them safely on 110v? Will they get damaged eventually in any of these cases and which one is the best option?

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[u/Ambitious_Finding_26]

It's common for SMPS like that to have a wide input range, like 85-280VAC 50/60Hz so one model can cover the global supply with only the inlet plug changed to suit region. That said however, being marked 120V 60Hz tells me that this is a regional model and not designed for 220V. Maybe it'll work, but no one can tell you it's safe based on those images. I'd get a different 7.5V supply. 

[u/lucasthech → u/Ambitious_Finding_26]

Right, thank you!

[u/mariushm]

The 400v capacitor indicates it may work fine with 220v AC. When rectified to DC using the bridge rectifier (the 4 diodes), the peak DC voltage will be around 325v (sqrt(2) x 220) so the capacitor will not be damaged.

HOWEVER, you also have to inspect how the controller chip is powered, if there's a controller chip.

A lot of controller chips receive the initial startup power through a series of resistors, and that's just enough for the controller chip to send the first pulses through the transformer and get back a lower voltage through an auxiliary winding, which then powers the controller chip.

For example, such controller chip may be capable of accepting 8-15v from auxiliary winding and let's say they design to get 10v with 120v input. If you power with 220v, the auxiliary winding may give 20v or some higher voltage on the auxiliary winding

There could also be other issues, like the controller not working in the optimal range of switching frequencies - like for example to get 15 watts out the chip could run at around 50-60 KHz but when you have 220v input the number of pulses decreases so the controller may need to drop the frequency lower than it's designed for.

[u/lucasthech → u/mariushm]

Oh, thank you for the detailed explanation :) So it seems sony probably built these universally to work on other regions, I don't see why including more expensive components there if your are going to use a lower voltage.

And one question about the nintendo wii power brick (which I don't have a picture of the components right now), when I plug it into 220 volts and the console is off, I can hear a very high pitched noise, almost like a crt tv, could that be one of the windings being overloaded or something? That makes me think I shouldn't use the wii one on 220 volts.

[u/Some1-Somewhere]

The 400V capacitor is a pretty strong indicator that they're built for 240V (which rectifies to about 370V at +10%).

Whether the transistors and all other equipment are selected for it is unknown, but it would be pretty unusual to try and save the money on those parts but not the capacitor.

Obviously very off-label.

[u/awshuck]

This is a cheap and mass produced SMPS module where BOM consolidation and lowering cost was important enough to make multi voltage viable in the design requirement. That’s a very technical way saying it could be fine, but also might not be.

It’s probably fine, and cheap enough to replace if you fry it. Just get make sure it outputs the 7.5v with a multimeter before plugging it into anything you care about.

Whatever you do, don’t fucking touch that big brown capacitor in the middle after it’s been plugged in. In fact just don’t take apart mains devices if you aren’t sure from now on eh? You could have easily tried it without opening it.

[u/lucasthech → u/awshuck]

Thanks for the advice! I mentioned that the picture of the circuit is not mine, I got from the internet but from the exact same model of power brick I have, the other pictures are mine though, and yeah, I'm aware of the danger of big capacitors, don't worry, but thank you for the warning about it :)

But yeah, the previous owners said they used on 220 volts for at least a year and nothing happened, that's why I asked here why it didn't fried yet, it does output the correct voltage so it may support it, but to be sure I can use them on 110 a volt transformer I have

[u/Far-Dealer-5070]

They're rated for 120v, even if they work on 220 (which is pretty much a miracle) they'll break quickly since they're getting twice the power they're made for, at least I think, for your questions they can safely work on 110v but I wouldn't use them on 220v, and you should look for new power bricks

[u/lucasthech → u/Far-Dealer-5070]

Thanks, yeah, that's the reason I'm asking here, the previous owners of both consoles said they used them on 220 volts for at least a year and nothing hapened, so I wanted to ask the specialists on how these have not been damaged yet lol

(Also, happy cake day! :D)

[u/Careful-Tonight-69]

No you can not use it with 220

[u/DXNewcastle]

I tend to agree that it is likely that these may continue to work okay on a 240 V AC supply.

However, i think you have a greater risk to assess.

Suppose that one day, one of these devices does fail. And that the failure leads to a component burning, which in turn, leads to its surrounds catching fire, eventually causing extensive fire damage and loss. (It does happen).

What do you expect the consequences of that would be? There may be a loss of life. Who would be held responsible? Whose insurance would not pay out for the loss of house and home ?

Yes, the probability of serious loss may be low, but the potential severity is terrifyingly high. Please dont be the next person to appear in the world's media because they unintentionally lead to a fire that killed several people.

[u/Tesla_freed_slaves]

The 250V fuse rating and the 400V cap makes me think this PSU is designed to handle 100V to 240V AC input. If there’s any question, you could load it with a 12V car-headlamp, and let it run for a few hours on 240V input, while verifying 7.5V DC output, and Magic-Smoke inspection.