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KerrickStaley | 6 months ago

This problem seems prevalent on cheaper devices. When I buy a device and discover it has this problem I always return it. I've seen it on the Hypervolt Go 2 (which I returned and replaced with a Theragun Mini) and on the Hitachi Magic Wand Micro (which I replaced with a Dame Dip).

Like the post mentions, I think this happens because the devices are missing two resistors that are needed to indicate, when connected via a USB-C to USB-C cable to a charging brick, that the device wants 5V power. Resistors are cheap and I think the only reason they get dropped is carelessness.

The whole point of USB-C is that you can charge any device with any power supply.

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Aaargh20318|6 months ago

> This problem seems prevalent on cheaper devices.

I’ve seen it on plenty of higher-end devices as well; and even worse.

The worst offender I’ve encountered is the TermoWorks Billows. ThermoWorks is a well established brand that makes high end thermometers and is considered one of the best on the market. So I was quite surprised to discover how their ‘Billows’ product is powered.

The device itself needs 12v and has a USB-C port for power. You’d think it would do USB-PD to negotiate it’s power needs so you can just use any old USB-C adapter. Not the case. It comes with a USB-A to USB-C cable and requires a special adapter with a USB-A port on it that puts 12v on the pins that normally supply 5v.

I have no idea how they came up with this abomination. Why even use USB-A connectors if it’s not going to work with a standard USB-A adapter, and why supply an adapter that’s basically going to kill most USB-A devices you plug into it? If you have a custom adapter anyway, why not just use a simple barrel connector? Why put a USB=C port on the device if it can’t use USB-PD?

I can imagine some Chinese ali-express product using such an abomination to save a few cents on components, but why would a well-respected brand like ThermoWorks ship such a thing? It boggles the mind.

gizmo686|6 months ago

I've seen even worse. I was upgrading an old device that had a 12v barrel connector, and was happy to see the new one used USB-C instead.

It came with a power brick that I happened look at and noticed that the output voltage was listed simply as 12v (instead of all possible outputs like usbc bricks normally do). I hooked it up to a USB-PD breakout board I had and tested it. Sure enough, it output at 12v regardless of what is asked for.

Luckily, the device itself actually did USB-PD, so I was able to throw away that monstrosity before it fried anything. Annoyingly, the device only supported 12V, which is hot or miss on being supported by chargers, but at least a mismatch there isn't going to fry anything.

numpad0|6 months ago

So it's based on Qualcomm Quick Charge? QC is a competing, slightly older, slightly simpler standard to USB-PD that can do what you described. It's...useful sometimes.

KnuthIsGod|6 months ago

ThermoWorks products are made in China

and marketed to gullible Americans.

sschueller|6 months ago

This happens because these devices had USB microB before and the manufacturer just replaced the port without reading the spec.

Even some mainstream products have this issue. I have an automatic door opener from a large company and the battery pack has the same issue. It is shipped with a special cable you have to use as no other USB-C cable works.

imtringued|6 months ago

There is also another problem. The spec is large and it's not aimed at those who want to implement the simplest possible USB C compliant device.

Based on the table of contents the most promising section is "2.3.4 USB Type-C VBUS Current Detection and Usage" but it doesn't actually talk about anything you actually need. You're supposed to click through to the section "4.6.2.1 USB Type-C Current" where it shows the reference circuit, but it doesn't tell you the values of Rd, which are in section "4.11.1 Termination Parameters".

It's a 300+ page document where you must already know what you're looking for. If you didn't already know that you need two resistors, you wouldn't be able to figure it out with the spec alone.