I wanted to share this opinion on Hackaday about a topic that is the usefulness of a something that has become ubiquitous relatively fast.
This techonolgyy has a lot of potential, what do you think?
I wanted to share this opinion on Hackaday about a topic that is the usefulness of a something that has become ubiquitous relatively fast.
This techonolgyy has a lot of potential, what do you think?
What hurray? USB-C and PD are both monstrosities (though of course the mini and micro USB connectors were even worse). We already had a perfectly good low power standard, regular 5 volt USB. It’s just that higher power was wanted. But we have that already too, automotive 12 volt DC, and various options after that. It’s just the mobile phone industry’s obsession with thin, tiny connectors that are causing this.
We wanted our stuff to charge faster. We can’t pull more amps through the thin USB cable wires and contacts without turning them into detonation cord, so we increase the voltage instead, and due to Ohm’s Law, we get more wattage out of it as a result, so now we can charge your phone in 20 minutes instead of 3 hours. And because some devices can take advantage of this, and some can’t, we had to build some logic into the power delivery system to avoid frying things.
Yes, you have 5 V. THen you have outomotive 12 V. But now you would have also automotive 48 V. USB-PD is one standard and can deal with different level of power requirements, from headsets up to laptops. And then you can use for other things as well, in a way that can be more practical than dealing with 110-220 V AC.
Is it a monstruosity? I don’t know honestly. I trust hackaday in that sense, and they usually praise it, without any hidden reason, I think.
Also, if you read the article, you can see that it is also a continuation of one from a few years back, before USB_PD was widespread. It touches also the points that you wrote. Give it a read:
https://hackaday.com/2016/12/21/so-wheres-my-low-voltage-dc-wall-socket/
I wouldn’t say usb pd is one standard. There is a combinatorial explosion of devices and cables with different voltage support, current capacity, presence or absence of E-mark and of Thunderbird, the famous incident where a bad cable blew up Benson Huang’s laptop, etc. If you intersect down to the universal standard in the middle, it’s just plain 5 volts like before.
And are really going to push 240W through that teeny connector and not have any melt?
The whole USB-PD standard is massively over complicated and that makes it a lot harder to implement in home made equipment. You pretty much need a dedicated chip just to negotiate with the power supply. The whole protocol should have been made simple enough to implement on any 8 bit microcontroller and not be locked behind a proprietary standard.
There does need to be some way to negotiate higher voltages. There is just too much voltage drop when you need more than a couple amps at 5 volts.
It would be nice to have a standard for supplying unregulated 48V DC at 1KW or more without any negotiation or electronics required and with a robust connector that won’t break if it gets bumped. That would be very useful for off grid solar systems since the power would come directly from the batteries.
I thought solar panels used Anderson connectors pretty standardly. I wouldn’t call it low power but in electronics I wouldn’t call 100W low power either. We basically need 5v 15w for phones, 12v for bigger stuff (laptops) up to say 150W. After that, AC might be better since you can use transformers. I guess we need super high power DC for charging cars. Tesla seems to be the de facto standard. There is no reason to use that connector in a phone.
Solar panels use MC4 connectors. They are weatherproof, they lock together and they fit the thick, weatherproof cables used for solar power. They can handle fairly high voltage, but they can not be connected or disconnected under load though.
The Anderson Powerpole connectors are a good choice for DC power. I use Anderson PP30 connectors for most of my 13.8V stuff. They are robust and fairly small.
Most electronic devices will just rectify AC into DC before stepping it down with a switch mode power supply since that’s smaller, lighter, and cheaper than using a mains frequency transformer. It’s pretty rare to find a mains frequency transformer in consumer electronic equipment today.
Yeah probably true about 60 hz transformers, even for higher powered devices like desktop PC’s. They still have pretty big internal inductors though. Maybe we need to bring more 208V 3 phase into homes and offices.
For permanent installations like most solar setups, I don’t think uniformity of connectors is that important, as long as it’s non-proprietary and you can order it from a catalog.
For phones and laptops, wireless charging is probably the way forward. More than additional standardized chargers, I want standardized and swappable batteries, for phones, laptops, power tools, etc. The chargers will follow.
Wireless charging is super lossy though and generally far slower than charging over USB. I’m sure some of that can be overcome with more research but I have a hard time believing wireless anything will ever be as efficient as wired
Phones or laptops should probably accomodate wired charging (though count on Apple to eliminate it anyway), but most of the time, wireless could be the norm. Convenient, avoids wear on connectors, etc. I think there are some Samsung phones with two-way wireless charging, so you can stack one phone on top of the other and transfer charge. That seemed crazy to me given the non-removable batteries but whatever.
That reminds me of another USB PD idiocy that I forgot to mention earlier. There are many devices like power banks and even some phones, that can both send and receive charging current. E.g. you’d charge your power bank from a wall cube, and later use the power bank to charge your phone. In the pre-USB-C era, power banks had separate connectors for input and output. Now the two functions share a single connector and the cable is the same at both ends.
So if you plug one power bank into another, how does the setup know which one is to be the “charger” and which the “chargee”? The spec says they are suppsed to choose at random! I guess you are supposed to look at the activity lights and if the current is going the wrong way, unplug and replug the devices until it goes the way you want. This can lead to a situation where you plug your phone into a power bank, but the phone ends up charging the power bank instead of the other way around.
I imagine that if you are attentive enough, you can prevent this somehow, or at least intervene and reverse it when it happens. But it still seems like crackhead engineering to me.
And you have to pay like 5K to USB-IF to build your own implementation. Because everybody forgets that USB is proprietary.
But the madness of every vendor having it own proprietary conector is worse.
USB-C and USB PD may not be good enough, but it’s better than the previous alternative.