I have an older electrical device which I would like to switch to charging with a USB C cable and a standard USB power supply. The device’s power supply unit supplies 14V and 400 mA, so 5.6 W. The device documentation certifies it for 12V with 2 Ah.
I found a useful answer on stackexchange about the Source Power Rule for USB 3.1. This implies to me that my device is not compatible with 3.1 because at a power draw below 15W, PD 3.1 defaults to 5V.
According to Wikipedia, a USB4 DFP is required to supply at least 7.5W Type-C current, which is above the power requirements for my device.
Based on this, it seems to me that the power supply of my device is too non-standard to be supplied by a standard USB power supply. Have I understood this correctly?
Thank you for your help.
That is extremely useful, thank you.
Do I understand correctly that the PD unit is in the USB C plug i.e. can I change the barrel jack connection to the connection on my existing cable?
That’s what I understand. They might have one that doesn’t go to a barrel jack but I don’t remember.
You can also buy ‘trigger boards’ and wire it uo yourself if you like. I replaced all my barrel jack devices with USB.
https://www.ebay.com/itm/205338921886