This picture shows the ratings of a 35 watt USB PD power supply. You can see that higher voltage provides more power.

It's just a DC power supply where the output voltage is negotiated by the powered device

 

You are welcome to do anything you'd like, and I've laid out some options. You can follow those or continue to search for a cable that should not exist.

I think you're being ridiculously over -cautious with products by recognized manufacturers using USB chargers. USB is a recognized standard and plugging a name-brand device into a name-brand charger will pose no issues but rare exceptions do exist as you have shown. I've only heard of two cases of this, so it's rare.

Sorry if I have appeared argumentative. I was only attempting to explain the issues and possible solutions.

Hello again,

No problem I appreciate your input.

I thought someone did post a cable? It's not complete though. It is a barrel type DC power connector to USB C connector. I would have to add a cigar plug to barrel type DC power connector, then plug the barrel to USB C cable into that. That would be two cables instead of one though. I was hoping for one, but it's getting to the point where I'll do almost anything to get past this issue (ha ha).

You've actually posted some very good ideas and I may just go with one of those instead it looks simpler. I do appreciate your input no doubt there, so thanks for that.

I think my whole problem stems from the fact that i am not sure how a USB C connector would be wired to any power source, even just a regular 5vdc regulator. I suppose you use those pins called "Vbus" but I've also seen some resistors connected to the USB C connector so I am a little lost on that. If it was wired to a 5vdc regulator it should pass the standard, although I need to do that with 12vdc that's all.

Lastly, there is a hint from the manufacturer that the device will negotiate for the correct voltage, but it's taking time to communicate with them back and forth through emails. That would be nice to hear, then I would just have to find a cigar plug to USB C that can negotiate to 12vdc. There is still the chance that it will not be able to negotiate anything though.

 

Do you have manufacturer and model number for this device?

How about a picture of the power supply ratings too. If they "hint" at negotiation, you may be missing important details.

If this were my device, I would have already grabbed an innocent USB C cable (USB C – USB A cable would make this easier so you only have to sort out the + and – connections from 4 wires), soldered it onto the power supply and been done with it.

Yes, there are a plethora of wires in a USB C cable. That's why I made the suggestion as above or a USB breakout board. Let somebody else figure out the details.

 

Do you have manufacturer and model number for this device?

How about a picture of the power supply ratings too. If they "hint" at negotiation, you may be missing important details.



Yes, there are a plethora of wires in a USB C cable. That's why I made the suggestion as above or a USB breakout board. Let somebody else figure out the details.

Hi,

I am in contact with them but it takes time.

The hint was from R&D but i want to be sure they understand right.

 

Post a picture of the power supply please.

 

Post a picture of the power supply please.

Hi,

I can post a picture if you like, but it just looks like an ordinary 12vdc wall wart, a regulated type, with a cord coming out just like any wall adapter, and on the end is a USB C male connector. It's quite simple.

I have heard back from the manufacturer and they are now recommending a high power PD type USB charger. I still am not sure this will work though because they neglected to mention that it must also support 12vdc through a negotiation.
Because it came with a 12vdc wall adapter I questioned the negotiation process, if the device could do that, but they did not address that yet. They just said that a high power PD type should work.

So I guess my next step is to get a high power PD type charger that can do 12vdc and see what happens.
It's unfortunate I have to go through a 3rd party I can't seem to talk to R&D directly. That's probably because of the language barrier.

If you still want a pic I can take one, and thanks for sticking with me on this issue.
To take a pic I have to shut the device down and unplug because the most important thing is the "12vdc" marking which says it is a 12v dc wall wart. Could it be a 12vdc 'max' wall wart, i don't really know for sure. I do know that there is no negotiation going on because when I plug it in I can measure 12vdc right out of the C connector, so there is obviously no negotiation going on or else i would read 5vdc.
I cannot imagine a device that negotiates for higher voltage being able to take a 12vdc power source directly, but maybe some can, and still negotiate if need be.

What is being suggested (I called it a 'hint' previously) by the manu is that the device itself can do a negotiation, but that remains to be seen.

 

Hello again,

Well, as it turns out, i could *almost* say this was much ado about nothing, but it was really much ado about something.

The test revealed that the device can run with a proper PD enabled 12vdc (in) cigar plug to USB C adapter (out). This is surprising, so this manufacture must have made the C port both compliant with the PD USB C standard, while also making it able to accept a straight 12vdc input. That is pretty clever, that way they don't have to send a high-powered PD adapter that plugs into 120ac line voltage.

Notice I also specified "in" and "out" in the above description. That's because I found that some of the cables you see online go the other way, with the USB C being the input, and the other end being a barrel connector that supplies 12vdc. I also noticed that some of those 'trigger' devices do that too, they expect an input on the USB C connector and then with those tiny dip-like switches you set the voltage you want out. The onboard chip negotiates for whatever voltage you set it for, and that's the only voltage you get out of the little board. Pretty neat.

Ok, so I guess this is solved, but there may still be things to talk about related to this kind of situation.

Just so you know, the 'device' in question is a minicomputer made by GMK. They are based in China. The only way to power it is through the USB C connector and i didn't want to hook just anything up to it because it might damage it.

What this tells me now is that i can also buy a standard line operated wall adapter that is PD compliant, and be able to run the computer from that too. That was an issue as well, because the company is sending me a brand new line adapter to power the thing too. What happened was i asked them if i could buy another adapter and they said they would send me one for no cost, and i thought that was really great of them. The problem is, it is stuck in transit and taking a very long time to get here from China. It has been in NJ for some 10 days already but not moving anymore. If they lost it I'm screwed, so I would like to get another adapter somewhere and now I know what kind I can substitute if I have to.

I should also mention that I had to buy a PD compliant USB C to USB C adapter to go from the output of the cigar lighter adapter to the computer. That's what is required for PD operation. On top of that, the cable has to be rated for the power you intend to use it with, and the current rating has to be there too.