USB power information

Thanks. Very useful. I’ve been picking up bits and pieces as I’ve been going. You’ve filled in a lot of the many gaps I had left.

I need to get a little further along on my understanding of QC2. I’ve been waiting on some QC power sources so I can start experimenting.

I will say, I think ADB deserves a mention in the history of peripheral buses, especially since it was a universal (for Apple) serial bus, and Apple ditched it and went all-in on USB before most PC makers really committed.

WOW - great source of info!

thanks HKJ

You are probably right, it is just that I always have used a PC and not really looked at Apple computers.

Thanks for sharing!

Very nice compilation of info. I like the history refresher having lived through it from the beginning.

What do you use to negotiate quickcharge voltage levels for testing?

My own box, a Arduino nano with a few resistors. I needed something that do not use power from the usb power and allows me to connect my load in a four terminal hookup.

Thanks. That’s what I’m planning on doing since I haven’t found anything that someone else has already designed/tested for incorporation into otherwise dumb electronic devices.

Great job. Thanks for sharing.

That was educational. Thank you for the time to share that.

I’m using Samsung smartphone and the charger came with it is the Adaptive Fast Charging type,

while using Blitzwolf QC2.0 wall adapter or QC2.0 powerbank, it seems unable to do fast charging, what am I missing and what should I do to enable fast charging?

As I wrote above it looks like that protocol uses digital communication on the D- pin, this is not the same as QC, but some Samsung phones also support QC. If your phone will not do any fast charging it looks like it do not support QC.

@HKJ have you ever tested any XIAOMI power adapter? QC2?

The only stuff I have tested from XIAOMI is a AA/AAA charger/power bank and a power strip.

Would be great if you could test this next time: Xiaomi QC 3

Tad off-topic little question for you fellow electronic experts…

I have an ooold (30+ years at this point) electronic parts toolbox, with, among other stuff, a nice bunch of various brands electrolitic capacitors (Anodia, Bianchi, Trobo, …). I was wondering if it is worth giving that stuff a try (LoL!), because there are plenty of 25+V rated units. Oh! Well, I also have an old computer motherboard with a nice pack of 10-16V units which I could settle 2S2P and they're much likely to be in operative condition. O:)

Cheers ^:)

Please repost the request here: Review request for HKJ [USB Power Devices] That is where I look when I need more to test.

Probably not, newer capacitors are smaller with better specifications.
If you want to try them check for leakage current first, they may need to be connected to a voltage for some time first (Leakage current increase when a electrolytic capacitor is in storage, but will (slowly) go down again when voltage is applied).
If leakage current is fine, you also need to check ESR (Depends on application how significant it is).

How can i measure the max/peak current an usb device is using so i can pick the correct rated usb adaptor.

Any help is appreciated.

Thanks

John.

While some tablets may pull a good amount, I'd say it is quite unlikely to go beyond 10W (except maybe when playing ultra-heavy 3D games and stuff like that). Even with the “torch” on, I've rarely seen my XT1032 phone pulling more than 4W (I don't play heavy games).

Getting a good “charger” is inexpensive too: NILLKIN 5V 2A Travel Charger Adapter - EU PLUG BLACK @ GearBest

Reviewed by HKJ and good up to 3A: Nillkin AC Adapter 2.0A @ lygte-info.dk

Cheers ^:)

P.S.: sorry, didn't answered your question directly. For an Android device, the app “Battery Monitor Widget” will answer your power draw inquiry accurately.

I ordered an windows mini pc that comes with an 5v 3a adapter, I want to find out the max current it uses when running the cpu/gpu at max to see if any of my power banks would work with it.

Thanks

John.