this post was submitted on 24 Mar 2025
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AssholeDesign

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This is a community for designs specifically crafted to make the experience worse for the user. This can be due to greed, apathy, laziness or just downright scumbaggery.

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I just went to charge my kitchen scale and it wouldn’t work until I dug out a USB-A -> C cable and plugged it into my desktop…

It just reminded me of how many devices like that I have. This scale, my wife’s sound torc, some car jumperstarters, and I think a one or two more…

I assume it’s because they just slap a usbc port on a dumb 5v circuit that doesn’t have a power negotiation controller. So the cable and the charger cant figure out the power needs of the device are and just never send any.

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[–] [email protected] 1 points 2 weeks ago* (last edited 2 weeks ago) (1 children)

This bothers me more than literally anyone, however as an ee I do feel obligated to explain their crime against humanity.

The usb pd charge negotiation chip costs between $.50 and $3, cheaper for low current, like 12-18w, more expensive for 100w, also those tend to have more logic including battery management and even integrated buck converters.

Still unacceptable by any standards, but there are software aspects like debugging how the different charge and power modes work together, etc.

Largely it's inertia, buying a power brick and just putting a 19v is tried And tested, even though 20v is basically the exact same except for the pd negotiation.

The cheap ones assume you use the same cable that came with it, which are generally 2 wire only and have the resistor in the plug.

[–] [email protected] 9 points 2 weeks ago (1 children)

Way to complex and expensive. This just needs 2x 5.1 kOhm resistors between the CC pins and GND.

[–] [email protected] 4 points 2 weeks ago

Yeah, the cheap cables they provide are often only vcc and gnd with the data pair shorted in the plug.

Trying to use a normal plug confuses the controller.