Some Reversible USB-C Cables/Adapters Could Cause Irreversible Damage

TheRealHocusLocus writes: Three Decembers ago I lauded the impending death of the trapezoid. Celebration of the rectangle might be premature however, because in the rush-to-market an appalling number of chargers, cables and legacy adapters have been discovered to be non-compliant. There have been performance issues with bad USB implementation all along, but now — with improved conductors USB-C offers to negotiate up to 3A in addition the 900ma base, so use of a non-compliant adapter may result in damage. Google engineer and hero Benson Leung has been waging a one-man compliance campaign of Amazon reviews to warn of dodgy devices and praise the good. Reddit user bmcclure937 offers a spreadsheet summary of the reviews. It's a jungle out there, don't get fried.

Comments

Re:Stupid design

[Khyber]

Current doesn't kill silicon, voltage does. Example, you take an LED. It's a red one that runs at 2V. You can probably dump 3-4x that voltage through it without a resistor, and it won't care as long as the polarity is correct and it has adequate heat sinking. Now, this same LED has a reverse breakdown voltage. Many LEDs now days have native protection about double their nominal operative voltage. So for this LED, it can take upwards of ~4V reverse polarity. You give it 5V or higher in reverse, you will destroy the p-n junction.

This knowledge is what is used to design LED arrays which can run natively off wall power without any power driver circuitry.