I'm working on providing a stable supply of 5V power to a Raspberry Pi over the micro USB input port. One possible issue I've noticed is occasional instantaneous dropouts when switching over from battery power back to the feed from the wall after a brownout. These dropouts are very short, less than a tenth of a second at most, but I'm worried that it might cause the Pi to reboot, which has a chance of damaging the SD card.
What I'm unsure of is how short of a delay in power the Pi can handle before shutting off (if any). I know from experience that laptops and desktop pcs can handle a second or two before shutting down if you accidentally pull the battery or the plug on them, but I dont know if that's something that the Raspberry Pi can do as well. Looking inside I see most PCs have decent sized capacitors inside that can probably hold a small amount of charge when the power supply gets cut, but the Pi only has surface mount capacitors, which I would assume are much smaller capacity.
Does the Pi have any ability to ride out extremely short power interuptions at all, and if so, how long?
5V
or3V3
on GPIO header to drop out. There is not much dedicated charge storage and only a 200 mikes at most on the supply line so I suspect the hold time to be a fewms
at best.