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My cat water fountain comes with a spicy USB power adapter

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Re: My cat water fountain comes with a spicy USB power adapter

#52

Earlier quoted context omitted.

I think when it comes to safety restrictions should be there. The hacker in me hates it too but just imagine if a small portion of standard-looking outlets did not output 220V (or whatever standard you have) and say 330V. Many applicances would break, or perhaps even catch fire. If there were many different USB-A devices and people were used to checking the voltage output before plugging, that might not be needed, bu…

From my experience appliances tolerate a wide range of voltages. The outlets in my house routinely deviate from the standard 230V, with the lowest I have seen at 170V and highest at about 260V. I have not had any appliance malfunction. Edit: I am not advising anyone to deliberately do stupid things, simply mentioning that from my experience the builtin margin is fairly large.

You (or your landlord) should probably hire an electrician to get that checked out – especially the higher voltage might be indicative of some scarier failure modes.

A voltage drop of 25% could also mean you have semi-broken wiring somewhere, which can cause fires or shock hazards on faulty appliances.

Re: My cat water fountain comes with a spicy USB power adapter

#53

Earlier quoted context omitted.

I think when it comes to safety restrictions should be there. The hacker in me hates it too but just imagine if a small portion of standard-looking outlets did not output 220V (or whatever standard you have) and say 330V. Many applicances would break, or perhaps even catch fire. If there were many different USB-A devices and people were used to checking the voltage output before plugging, that might not be needed, bu…

From my experience appliances tolerate a wide range of voltages. The outlets in my house routinely deviate from the standard 230V, with the lowest I have seen at 170V and highest at about 260V. I have not had any appliance malfunction. Edit: I am not advising anyone to deliberately do stupid things, simply mentioning that from my experience the builtin margin is fairly large.

Thats quite a spread. Is it up to spec where you are?. In Australia we have 230V nominal, but the allowed range is from 216 (-6%) to 254 (+10%).

Re: My cat water fountain comes with a spicy USB power adapter

#54

9v or 12v over USB-A is reasonably common here in Asia... You always need to check the voltage rating before randomly plugging stuff in if it isn't from a big manufacturer. For example, the handwarmers I'm using right now are USB-A at 12 volts, but have a dial to adjust the voltage up and down between 0 volts and 12 volts to adjust the temperature (I think it's actually PWM on the 12v power lines, but haven't actuall…

Where in Asia? I lived in China from 2010 to 2019 and the only voltages I've seen on USB A ports is ~5V and ~4.2V. The latter on the charger for some rechargable bicycle lights.

Re: My cat water fountain comes with a spicy USB power adapter

#55

I am concerned that there are no pictures of the adorable cats in the post. It sound like the manufacturers just see USB-A as a convenient and cheap connector for delivering power.

Hi, author here, I've fixed that in the post now.

Great news!

By the way, are you Finnish? I've never seen an 'O with tilde' character before.

Re: My cat water fountain comes with a spicy USB power adapter

#56
post #45

Earlier quoted context omitted.

There's a deceptively similar mark that stands for China Export and does not indicate EU certification[0]. [0] https://www.kimuagroup.com/news/differences-between-ce-and-c...

Wow, that's incredibly close. I assumed there would be a public database of CE (European) approved devices or manufacturers, but I can't find one from a quick search.

CE mark (the real one) is self certified

Re: My cat water fountain comes with a spicy USB power adapter

#57
post #45

Earlier quoted context omitted.

There's a deceptively similar mark that stands for China Export and does not indicate EU certification[0]. [0] https://www.kimuagroup.com/news/differences-between-ce-and-c...

Wow, that's incredibly close. I assumed there would be a public database of CE (European) approved devices or manufacturers, but I can't find one from a quick search.

The CE marking is a self certification program, and there isn't an approval process. All the can happen is that you can get fined after the fact for applying the mark to products which don't fulfil the necessary requirements.

Re: My cat water fountain comes with a spicy USB power adapter

#58
post #38
post #28

This actually makes me quite happy that most stuff does not come with a wall adapter anymore these days, but only with a USB plug. There are much worse things than 7V that a bad adapter can output. One of the scariest failure modes I’ve recently learned about is a supply that still provides 5V between both pins – but 225V and 230V to ground, respectively…

> respectively not sure I follow you. can you clarify what you mean by both 225v and 230v to ground? You are measuring the potential between ground and USB output?

Yes, and given that USB devices usually don’t have protective grounding (since they expect to be supplied 5V to ground at most!), you just might be what eventually provides that ground connection when you touch a conducting part of the case…

Re: My cat water fountain comes with a spicy USB power adapter

#59
At 7.5V, any properly engineered consumer device you plug into that port should do one of two things:

1. just accept the 7.5V and charge happily.

2. trip overvoltage protection and refuse the charger.

That doesn't make this okay, it just means it isn't catastrophic.

Note that I said consumer device. If I plugged one of my microcontroller dev kits into this thing, the magic smoke would be released pretty quickly.

Re: My cat water fountain comes with a spicy USB power adapter

#60
post #52

Earlier quoted context omitted.

From my experience appliances tolerate a wide range of voltages. The outlets in my house routinely deviate from the standard 230V, with the lowest I have seen at 170V and highest at about 260V. I have not had any appliance malfunction. Edit: I am not advising anyone to deliberately do stupid things, simply mentioning that from my experience the builtin margin is fairly large.

You (or your landlord) should probably hire an electrician to get that checked out – especially the higher voltage might be indicative of some scarier failure modes. A voltage drop of 25% could also mean you have semi-broken wiring somewhere, which can cause fires or shock hazards on faulty appliances.

I did but unfortunately it quickly turned into all parties involved blaming each other (it's your utility, it's your installation...) and it got nowhere. For the past year it's been much more stable than before so I don't worry too much about it.
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