So you think the two PD outputs can be directly paralleled?
It would be great if we could buy that PCB without the plastic case for less than $99. Interested in how warm it gets at dual 60W.
That’s what I think anyways, ultimately the grounds would not be connected until after the negotiator boards
Just found this boost converter that looks decent too for such a small size
Interested if @jaykup has input or @Battery_Mooch
Maybe I would need to add a diode on the outputs of the negotiators to prevent equalization
According to this document:
The actual delivery voltage tolerance is 5% on the 20v output
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Now I really just want something like the PDS100 but with buck features up to 50V+ for board pd output. I guess a separate PD out battery would make sense because it could be very compact.
USB-C charging a board is a really cool idea. I think your plan will work as long as you use 20v USB-C chargers.
Kovol 2 port PD running to two PD receivers set to 20v, parallel output running to the boost converter set to 42v running to the battery.
Two issues you may run into - those boost converters can get hot, and I believe the watt output is reduced depending on the distance between the input and output voltage… but both of these can be figured out when you experiment with it!
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I’m pretty sure you will not be able to parallel those two channels. Even if you use diodes on their outputs, so the inevitably higher voltage one doesn’t feed into the lower voltage one, the two channels of those USB charging adapters (or two separate adapters) will just be fighting each other to regulate the output. One channel will just shut down while the other tries to supply all the current.
If you’ve got the budget and time though, give it a shot! 
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Can you also charge with just one?
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Check continuity between their grounds.
But I don’t think paralleling the outputs will work. That can’t be done with standard switching supplies. They both need to share and control certain feedback voltages to control how each reacts in order to not “fight” each other.
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Could you explain this for me? Sorry, some questions…
- PDS100? What device is this? It runs at higher than 12S output?
- PD output battery? A powerbank with a USB PD port?
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The charger is already on the way, the boards are cheap. The question is just how I generate a load to test my theories
This is what I was slightly concerned about. I know it would be different if they were separate isolated power bricks too
Yep of course, so worst case scenario I just use one and still get 100w charging potential
I wonder if that’s where something like that TI chip could come in. I’m no EE though so I don’t really know how to design that kind of circuit
it has a max of 32V input so to use it with even a 10S battery you need an extra buck. I assume you could design the PDS100 differently to take much more Voltage.
This would be so your board can charge your phone or whatever, but given it does not exist this moment you could just make a separate PD powerbank built into the board instead.
Unfortunately, no. You can’t directly parallel isolated outputs either. You still have both fighting to regulate the output.
Which TI chip?
The one that sets up Power DUO charging? I believe chip just allows for higher current to pass through the circuit than the normal 5A without overheating. It’s not a chip to parallel power sources. It’s just a MOSFET switch that can lower its resistance so more than 5A can be fed via a single cable without overheating the chip.
You still need a single 10A power source (and beefy USB cabling) before that chip.
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Arrgghh…thank you. I should have done a search first.
Thank you for the info!
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What kind of issues could said fighting cause?
Extra heat? Extra chip wear?
Ah I see
What kind of load could I come up with to get some testing done with this stuff? Idk what people normally use, I don’t really want to buy an actual load bc those are expensive. I’ve heard 100w incandescent bulbs work before
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In order to get around that my idea was two modular packs not connected that each use one PD charge output. Issue is they would need to be not connected in parallel during if I am not mistaken. I guess place the USB PD charge port in a way to prevent it from being plugged in while connected to the board.
Hmmmmm
But would it break the sender or receiver
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One or both supplies could burn out.
If decently made though it’s more likely that one will shut down and the other will try to supply all the current. If that is above the supply’s rating then it will shut down too.
Surplus power resistors from All Electronics or MPJA can work great or light bulbs too. With a fan on them you can run the resistors at their full power rating and they will probably “only” reach about 200°C.
If using bulbs then just don’t go over the voltage rating. Small 12V automotive headlight bulbs can work well too since it’s so easy to tailor the load by putting them in series/parallel.
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They would be directly paralleled when connected to the board though since they would both be feeding the pack.
Wait…I think multiple things are being talked about and I’m not keeping them apart. Are you talking about paralleling USB charging adapters (or adapter channels) to increase the charging current being fed via USB ports to boos converters to charge a board’s pack?
Or are you taking about using a board’s pack to create a PD port in the board for charging phones?
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yeah uh sorry I jumped in with talking about how to make PD input AND Output on a board, should have another thread for making PD outputs, this one is about “USB-C for Charging [boards]”
Then I was also talking about way to use two modular battery packs for getting more than one USB PD input for a board essentially, but how they could not be connected together on the board while doing that.
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Love a good experiment.
USB running single (1.12A before tester screen dimmed)
USB running in parallel (1.66A before tester screen dimmed)
A few notes:
- This is with a single plug two port 5v usb, not a PD smart version.
- These USB-C are battery protection modules, but certainly some chips regulating things.
- Load was limited by tiny 28awg USB extension cable
- Voltage is low since I plugged it into the battery output
However, shows it has a chance of working with the PD smart chargers.
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How long did you run it for, and did you notice any significant heating?
Cool that you got it to work though, I’m still going to attempt this with PD, hopefully it doesn’t blow up lol
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