DC to PD options

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1

Hey there,

I can find plenty of boards that will take power delivery (PD) as input and give you a DC output but I’m looking for the opposite.

I have many projects that I only have access to 18-20V/9A and need multiple PD outlets where each has the ability to negotiate voltage up to 12V.

Something like this but that accepts voltages up to 20v??

Any suggestions cheers

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2

Hi Dara

@ how many Amps??
Cheers Bob

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3

Hey wow, I didn’t know this standard was a thing. Pretty impressive; looks like you could just about charge a car battery off a little wall-wart!

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4

Am I reading this wrong?

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5

Enough to power an Orange/raspberry pi etc. New pi 5 is PD 5v5A!

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6

On the website they state that for the chip but all pcbs I found with that chip are designed for 3.7v in ;(

7

Hi Dara
Don’t quite get what you mean by power delivery and power output. Are they not the same. Confused.

If you want say 18 - 20V input and several outputs what would be wrong with several adjustable buck converters. You would have to make sure they will supply the current you want and just as important the parent supply will have to supply enough at any one time.

The total load cannot exceed the maximum power (Watts) that the parent supply can deliver. Don’t forget to factor in conversion efficiency which could be in the region of 85%.
Cheers Bob

8

PD is a charging standard. What is USB Power Delivery and how does USB PD work?

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9

Hi Kimmo
Thanks for that. Explains (or confuses) a lot.
But you will have to excuse my age. Back in the day PD used to be “Potential Difference” expressed in Volts or EMF (Electromotive Force) so you can understand my confusion with PD and power output.
Cheers Bob

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10

I’d never heard of it, but the way Dara phrased it, with (PD) in there, alerted me to it being a thing I could look up. Actually I’m a bit amazed I’ve never come across it, given it’s as old as USB C…

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I too was amazed by how the USB Power Delivery Standard has evolved.
After a bit of googling I came across this: https://www.aliexpress.com/item/1005005599749454.html
Is it the sort of thing you need ?

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12

You legend Stephen, exactly what I was looking for!!!

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13

Hi All

Actually in my case I am not as I have never had any reason to look. All I knew was that if I connected my Samsung (pretty basic) phone to a Samsung charger the charging time is shorter due to some sort of communication ability. That is all I have had to know about it so today I have learned something new. Always try to do that.

Stephen,
How did you come across that. Looks like exactly what Dara wants and I can now understand a bit more about the initial request.
Cheers Bob

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14

Hi Bob

I googled for “USB Power Delivery Control Module”.
It looks like there are SOC chips that must be inside these latest generation usb chargers.
There is a lot more going on inside that you would expect.
You should look at the datasheets.

Steve

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15

Hi Dara

No problem, update the forum to let us know how it goes.

Steve

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16

Will do. Here’s where I’m at ATM. Want to swap out the power brick (PD compatible) and run everything off the Ryobi battery. Ordered two of the modules you recommended. Will follow up in 2wks

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Hi Dara,

Very impressive, the ocky-strap holding in a Ryobi battery is gold.

Yes USB-PD in particular is a fairly complex standard that actually performs bidirectional communication between the charger and device, you can basically “ask” the charger how much power to provide (fantastic for minimizing E-Waste due to reducing the number of incompatible chargers out there).

It also allows for bidirectional power delivery, that’s part of the reason why some of the new smartphones can be used to share-charge or be used as a portable battery bank from the same port used for charging. It’s quite impressive and very new:

https://www.usb.org/usb-charger-pd

Yep, it still means potential difference too. Reminds me a bit of the IP problem (Internet Protocol, Ingress Protection, Intellectual Property) certainly makes working on custom networked submersible ROVs fun where all three terms can be used based on context :sweat_smile:

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Hi Bryce
People must have nightmares thinking all this confusion up. Wonder what will happen to=morrow.
Cheers Bob

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19

Fair points made there alright!
As for the ocky strap, I’ll swap that for a 3D printed, quick release, bracket once I know I don’t need the charging pack anymore :rofl:

20

Is that a typo of to-morrow?

Wow, you have been around a while!

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