4 ms·
This somewhat legendary teardown of an Apple charger is a fun read: http://www.righto.com/2012/05/apple-iphone-charger-teardown-quality.html http://www.righto.c
by xkemp 7y ago
This somewhat legendary teardown of an Apple charger is a fun read: http://www.righto.com/2012/05/apple-iphone-charger-teardown-quality.html http://www.righto.com/2012/05/apple-iphone-charger-teardown-...
Basically, they seem to do a pretty good job isolating high- and low-voltage circuits. As far as I understand it, it is air-gapped, and physically impossible to induce dangerously high voltage on the device side without some mechanical failure that bridges the gap.
- 8note 7y agoa USB pd charger could try to put out 18v to a device that's expecting 5v though, and that can still burn out the device
- xkemp 7y agoYes, of course. I was thinking of the risk of death and injury, not broken gadgets. Because it is somewhat disconcerting to think how often we/babies touch/stick in our mouth a cable with an almost direct connection to the grid.
- dfox 7y agoAssuming reasonable charger design (ie. at least some overcurrent protection) the internal ESD protection of USB-C port in the device that only ever expects 5V (think SRV05-4) should be more than enough to safely trip the overcurrent protection in the charger (or overload it enough that the destroyed component is the charger and not the device). On the other hand there are documented cases of USB-C PD between two device-ish things (ie. things that can be both power source and sink) failing in variously spectacular ways.
- extrapickles 7y agoThe problem is that the ESD protection can only stop short duration spikes. The device would have to have a fuse (or other overcurrent protection) to prevent the 20V @ 5A as allowed in the USB spec from destroying the ESD circuit.
- Dylan16807 7y agoA USB port should always have a polyfuse. And active disconnect isn't hard either.