Ok, here is my story…I like to tinker…I also like to come up with innovative ideas that might help people, sometimes my ideas are a bit grandiose and may or may not be practical
What I have come up with from viewing other OSHPark boards is a way to take an old junk ATX powersupply and be able to effectively power multiple USB items with proper DCP (dedicated charge port) protocols (meaning the item will charge faster because it is capable of pulling the current it was designed to pull to charge the battery rather than “trickle charge” at a much lower charge rate
First let me give you a bit of information to explain why I am doing what I am doing
USB - Wikipedia <-information on dedicated charging ports vs charging downstream port (data enabled charging, usually restricted to 500mA or lower)
Here is my story
I browse OSHPark for different little “projects” people make…stumbled across these two projects
USB Power Hub v1.0
https://oshpark.com/shared_projects/tqPuzeWK
Which provides 13 USB dumb power charging position, basically a 5vdc regulated USB connection, problem is, there is nothing that will let whatever you plug into it know if its data capable or a dedicated charging port thus pull more current for charging
I found this project then
USB DCP Enumerator / Charge Adapter
https://oshpark.com/shared_projects/NIDe7kjj
The thing with this one is it has an IC on it that is an intelligent charge controller, you plug an item in it, it will autoranging the correct level for the device to charge at, up to 10watts or 2A, but it’s only a single design
The design above had the Texas Instruments TPS2514 (a single port chip) its big brother the TPS2513 is a dual port autoranging chip
Data Sheet
I thus determined I would “tweak” it
The progression of my design is as such, shrank it down from 13 to 6 ports, shrank the board considerably, converted to pretty much all SMD components…version 1 had simple data port resistors/shorts (up to 1A per port charge rate)
USB 6 Port Hub Charge Adapter w/ DCP resistor
With a 100-130ohm resistor tied between D- and D+ on the USB plug anything you plug into it will automatically see the “short” and then adjust to a full 1A draw from the port (with losses thru the charge cable and whatnot of course) but will allow for faster charging
I then took it a step further
USB 6 Port Hub DCP Enumerator / Charge Adapter
This uses the TPS2513 per dual ports, it can now autorange up to 2A per port for very fast charging if the plugged in device is capable of such current draw to charge
I plan on using an old ATX powersupply with a load resistor on the 5vdc rail for stability, if you look at an ATX powersupply the bulk of the current is on the 5vdc rail very capable of pushing 20-30A or more with high accuracy regulation of 5vdc…tie this into the above boards and you can easily “quick charge” your devices (at their proper charge requirement levels) rather than wait forever because the device being charged won’t pull more than 500mA from a computer charging port