240 watts over a USB-C connector? What next, USB toasters and coffee pots?
I remember scoffing years ago at USB powered coffee warmers. Maybe the situation has changed.
USB Power Delivery: Plugging into the Benefits
21–30 of 127 posts
Re: USB Power Delivery: Plugging into the Benefits
#22Speaking of which, does anyone know a line of PD Decoy modules to convert barrel jacks to USB-C without the atrocious behavior of "oh, the charger doesn't have 12V, here's 9V have fun!" that the early ones all did? Ideally I'd like a little red light to come on or something, but I'd settle for not silently browning out the device.
iirc theres ones that do. However I dont recall there being any clean fix to the amperage constraint issues. Especially when a lot of usb-c chargers will vary output as they heat up with usage. Which is kinda part the issue, usb-c charging bricks, they aren't usb-c power supplies, there is no expectation of sustained output capacity. Thankfully at least some the multiport ones have renegotiation more or less solved c…
sounds like someone needs to create a DC-DC charger
Re: USB Power Delivery: Plugging into the Benefits
#23I've basically stopped buying any portable electronics unless they take USB-C. Currently travelling with a laptop, watch, toothbrush, eReader, camera, bug-bite treater, and phone - all charging from the same power brick. I'm guaranteed of getting a replacement cable / charger wherever I am in the world if I need it. The only slight snag is some cheaper itema refuse to use PD and insist on plain 5V/2A - buy most decen…
I'm hoping we'll see most e-bikes at least use 240W usb-c pd charging (I figure I have about a decade until I will wish I had some assist and buy one, so probably by then, they'll have gotten there...)
I also have assorted products that won't charge c-to-c (some from respectable manufacturers even, like Philips), but I see you can get little adapters with 5.1K resistor you plug into said crappy devices to cover that, I will have to try some out.
Re: USB Power Delivery: Plugging into the Benefits
#24Earlier quoted context omitted.
> By "that mode", do you mean "1.5A @ 5V" permitted by BC Neither - OP means devices with missing CC resistors which will fail to charge with a compliant PD source. (The A-to-C cable works because it provides 5V Vbus unconditionally.)
The A-to-C cable often does not work because the resistors are supposed to be in there . So if you are having complete charge failures, try a different cable.
A-C cable assembly always works, CC signal is connected within the cable to Vbus via 56kOhm resistor, but that's only relevant to the downstream port, not to the upstream USB-A power sourcing port which does not have access to the CC signal. Upstream port provides power unconditionally within some limits depending on port type (CDP/DCP/USB3.0/2.0 data port/...).
Re: USB Power Delivery: Plugging into the Benefits
#25Earlier quoted context omitted.
Same! I've also returned a few USB devices that ship with a USB-A to USB-C cable and ONLY charge in that mode, they also MUST charge with USB-C PD. The two so far were a therapy light and some Zippo hand warmers. Like, who in the hell would design a device that has a USB-C port on it where only a fraction of chargers will work on it. It feels even worse than proprietary charges, because you see a USB-C port on it and…
The thing is, making a 5v-only device PD-compliant is literally one resistor. It costs well under a penny. It's pure ignorance, not a decision, but the lack of one. Lack of caring, lack of having an actual engineer involved, just slapping an oval-shaped port into a product where a trapezoidal port had been, and blindly thinking that magically makes it spec-compliant. Or not thinking about the spec at all. I return th…
There's an otherwise decent shortwave radio out there that was originally charged with a micro-usb, then they released a "new" USB-C model...except it will only charge with a 5V brick because they literally just swapped out the ports. Really annoying.
Re: USB Power Delivery: Plugging into the Benefits
#26Earlier quoted context omitted.
The A-to-C cable often does not work because the resistors are supposed to be in there . So if you are having complete charge failures, try a different cable.
A-C cable assembly always works, CC signal is connected within the cable to Vbus via 56kOhm resistor, but that's only relevant to the downstream port, not to the upstream USB-A power sourcing port which does not have access to the CC signal. Upstream port provides power unconditionally within some limits depending on port type (CDP/DCP/USB3.0/2.0 data port/...).
That's how it's supposed to work, yeah.
But there is some trash out there in the world. A lot of it, actually.
Some naughty cables work with some naughty chargers work with some naughty devices. Postel's Law in action, I guess?
Usually the best place to fix it is by getting rid of the bad cables. Usually.
Re: USB Power Delivery: Plugging into the Benefits
#27Earlier quoted context omitted.
The thing is, making a 5v-only device PD-compliant is literally one resistor. It costs well under a penny. It's pure ignorance, not a decision, but the lack of one. Lack of caring, lack of having an actual engineer involved, just slapping an oval-shaped port into a product where a trapezoidal port had been, and blindly thinking that magically makes it spec-compliant. Or not thinking about the spec at all. I return th…
There's an otherwise decent shortwave radio out there that was originally charged with a micro-usb, then they released a "new" USB-C model...except it will only charge with a 5V brick because they literally just swapped out the ports. Really annoying.
I'd imagine that a significant portion of the shortwave radio community is capable of soldering in the two resistors.
Re: USB Power Delivery: Plugging into the Benefits
#28Earlier quoted context omitted.
The thing is, making a 5v-only device PD-compliant is literally one resistor. It costs well under a penny. It's pure ignorance, not a decision, but the lack of one. Lack of caring, lack of having an actual engineer involved, just slapping an oval-shaped port into a product where a trapezoidal port had been, and blindly thinking that magically makes it spec-compliant. Or not thinking about the spec at all. I return th…
It's two resistors, actually. But they cost $0.0003 each (that's 0.03¢, or just around 3,333 of them for US$1) from distributors. Though there appears to be a bit of a stock crunch right now. So... yeah. The bigger issue is not really the parts cost, it's the fact that it adds an extra part to the design that has to be purchased and tracked and assembled and blah blah blah. This is the real reason it often gets left…
These companies are not manufacturing the device PCBAs, that is done by dedicated companies such as Flex. The PCBA manufacturing companies have warehouses of different resistors, and 5.1kΩ is extremely common. In fact, most PCB resistor values are quite flexible, to save on SKUs (in practice, to save on loading another carrier on the PnP machine) often if a specific resistor needs a specific value then all (or most of) the other resistors will use that value.
Re: USB Power Delivery: Plugging into the Benefits
#29I'm looking forward to USB-C PD small format factor PC's. A decent amount of room in the PC cases is taken up by the power supply. And if USB-C could somehow provide a range of voltages to the motherboard, SFFPC's could be downsized even more
The issue is that a USB charger is not a USB power supply. A charger does its best, but makes no guarantee of constant power delivery or duty cycle. The power supply absolutely must provide its rated output at 100% duty cycle.
Re: USB Power Delivery: Plugging into the Benefits
#30Speaking of which, does anyone know a line of PD Decoy modules to convert barrel jacks to USB-C without the atrocious behavior of "oh, the charger doesn't have 12V, here's 9V have fun!" that the early ones all did? Ideally I'd like a little red light to come on or something, but I'd settle for not silently browning out the device.
Actually, that was 5v, not 9!