What was the brand name of the "trusted" device that supplied this no-name power supply?

It came from an NRG go powerbank, a large one rated at 25600mAH which itself, ironically, does PD perfectly. I have three and they've been very reliable. The first t wo came with only USB Type-C cables, the lat one included the charger. I only used the supplied charger a few times with the powerbank because I have other chargers on the "charging shelf" where the myriad chargers for both batteries and devices live.

It works fine with the powerbank that has no problem with 12V into the Type-C connector. Since the NRG go powerbank did PD I didn't even consider if the charger did. My speculation above about the reason for the fixed supply was wrong. Testing, the powerbank charges just fine (if slowly) from 5V. I suspect the slow charge if you don't have a high voltage charger could be the reason instead.

 

Nothing you said, except that I owned both things, was correct.

What ever. I have a son like you, never wrong even when he is.

 

Hi Guys,
Topic please.
Mod.

 

Why not use USB connections and 5 volts for all low voltage DC devices? It's convenient and saves having a collection of incompatible wall warts for everything. And a USB power bank makes a handy universal battery for all the USB-powered devices. This is a no-brainer for me, and saves you from the evil center-negative, device-destroying wall wart that looks like all the rest.

For stuff requiring higher voltage, USB C PD is a great solution. One large power supply to handle all of your electronics. This is why I built a USB C PD to 12 volt adapter for my CPAP. When traveling, one PD charger takes the place of a bunch of different chargers. Hmmm. My electric shaver could probably be adapted to charge from USB too....

 

Let me see if I'm understanding this correctly. You, Ya'akov, owner of both the light and the power supply/charger, a light you knew needs 5V and the charger with a large orange warning label saying 12V killed your light? Do I have it right so far?

So then it is the chargers fault? Or should the owner of the items involved not do any charning when in an impaired state? That to me seems the likely problem not the chargers. It goes back to the old sayings, "guns don't kill people, people kill people" or another one "spoons don't make people fat people make people fat". We need to include a new one, "chargers don't kill lights, people kill lights".

There is something in the legal world they call "expectation". If a person has some reasonable expectation of something to be true and it isnt, a company can become liable. With USB i think we all have a little expectation of what we expect to see or how it should work. With that in mind, i firmly believe it is wrong to use a connector in an application that usually uses that connector for something specific and different without clearly marking it as such. Recall that "USB" stands for "Universal Serial Buss" and if it is universal then it should work in every application not just some, and certainly not be capable of blowing out your device because it is not standard.
The only alternative is we would have to measure every single thing we go to use with a connector, and it's not easy to measure something that has to negotiate the connection, not easy at all. You literally have to have a device that you can plug into it to see if it works or not, or have some very sophisticated test equipment. Maybe you can find some tester on line or something.

Please read my post too about the USB output connector power supply.

You should be happy he posted this though it may one day save your azz

 

You should be happy he posted this though it may one day save your azz

Nope, while I'm no engineer or even the sharpest knife in the drawer, the first thing I look at on a wall wart or any power supply is the output voltage. Working in a shop for my whole life taught me things that I'm guessing weren't taught in college.

 

Well I can add the Samsung Adaptive Fast Charging Wall Charger that came with my wife's and my phones which use the new USB C connectors is labeled Output 9.0 VDC 1.67 Amp or 5.0 VDC 2.0 Amp. The Model # EP-TA200. This model charger seems to show up being used for a number of devices. I know the phones charge fine using USB 5.0 Volt supplies so I guess when a phone is connected it negotiates for 5.0 Volts or 9.0 Volts? These are the chargers which came with the phones.

Nope, while I'm no engineer or even the sharpest knife in the drawer,

Naw, you are a pretty sharp knife. I know these things!

Ron

 

There are many connectors suitable for 12volts that are not at all similar to a USB connector. Use one of them and avoid doing damage.

Thank you for the suggestion.

 

Nope, while I'm no engineer or even the sharpest knife in the drawer, the first thing I look at on a wall wart or any power supply is the output voltage. Working in a shop for my whole life taught me things that I'm guessing weren't taught in college.

Oh that's great. I usually do that too, but with USB C it's a little harder to do that not sure if i have an adapter for that. I do have for USB A male and female, looks like maybe i should invest in a USB C type adapter too.

But how do you intend to measure the output, and more to the point, how to interpret the output voltage? It may not put out any voltage at all until it is connected to something that can negotiate. Maybe see if it is putting out more than 5v right off?

I havent tried this yet so as long as we are on the topic maybe you can try this and give some advice here on the best way to measure this, and hopefully it works on all the USB C devices we run into.

 

But how do you intend to measure the output, and more to the point, how to interpret the output voltage?

Read? Both the primary/input and secondary/output voltages are printed on any wall wart I've ever seen. Or for that matter any power supply.

 

Well I can add the Samsung Adaptive Fast Charging Wall Charger that came with my wife's and my phones which use the new USB C connectors is labeled Output 9.0 VDC 1.67 Amp or 5.0 VDC 2.0 Amp. The Model # EP-TA200. This model charger seems to show up being used for a number of devices. I know the phones charge fine using USB 5.0 Volt supplies so I guess when a phone is connected it negotiates for 5.0 Volts or 9.0 Volts? These are the chargers which came with the phones.


Naw, you are a pretty sharp knife. I know these things!

Ron

Yes, which is how it is expected to go. The charger supplies 5V unless the device negotiates 9V. If the charger in question simply had no output without negotiation, that would have been fine. Instead it just puts 12V on the output no matter what is connected.

 

Yes, which is how it is expected to go. The charger supplies 5V unless the device negotiates 9V. If the charger in question simply had no output without negotiation, that would have been fine. Instead it just puts 12V on the output no matter what is connected.

Yep and that is what became the gotcha. Just wish it would have been a less expensive lesson learned.

Ron

 

Read? Both the primary/input and secondary/output voltages are printed on any wall wart I've ever seen. Or for that matter any power supply.

Ok i agree that's good advice. Also, try to match up the original wall wart with the device.

However, sometimes that wont help. In the case of the power supply PC board i talked about earlier it just had a USB A female output not labeled. The USB hub i talked about that came with a 12v wall wart, some come with 12v wall warts and use a buck to convert that to 5 volts.
I guess then the only thing we can do is check the documentation carefully. In the case of the USB hub though i dont think they give any documentation that specifies "can use with a 12v wall wart" or, "can not use with a 12v wall wart". So this can still get a little tricky.
I do appreciate your suggestion though.

 

Here's an article that I found interesting. Relevant to the discussion in this thread:

We tested 43 old USB-C to USB-A cables. 1 was great. 10 were dangerous


​

In a nutshell, each cable is supposed to have a 56k ohm resistor in it. This lets your phone, tablet, or laptop know if the USB-C port is connected to an older square USB-A port or not.
If the device senses the 56K resistor, it limits the amount of power it draws from the port. If, however, there is no 56K resistor, the phone or tablet assumes it’s connected to a higher-power USB-C port. In that state, the cable can potentially draw too much power from the port it’s plugged into, burn the port out, and sometimes cause damage to connected devices.

 

Thank you for sharing that.

Ron