Some "branded" and "not so cheap" ones may not be suitable either - depends upon whether they were "designed" to be PSU's or "chargers". The "specs." may be "the same" but the interpretation and requirements are different.TideMan wrote:In the last few days, I've been through 4 different power adaptors that look like this:
All were rated 1 A, but none could produce enough current to run my RPi.
Fortunately, it's my 3rd RPi, so I have other power supplies I can try, otherwise I would have suspected a faulty RPi.
This is by way of a warning for beginners: don't trust the current rating on cheap power adaptors - most of them are crap.
I'd not come across the "500mA requirement" (but then, being retired, I don't read "formal specs." much these days ). You may be interested to discover that (at least for the ones I've measured) USB A to mini-B cables are worse - FWIW, my, fairly basic, measurements of a number of cables can be found at:jojopi wrote:There is an extra problem with the type in the original picture. Even if it meets its specifications, it only needs to provide 5V 1A at its socket. USB A to µB cables are only required to carry 500mA at the allowed voltage drop. (Even assuming they are are not themselves rubbish!) So if the supply provides 1A, the voltage may be out of spec at the other end of the cable.
Power supplies with a captive cable are likely to be better because then their specification applies to the plug end.
(Having said that, I have several Pies powered from PCs and TVs using USB A to µB cables. That is technically out of spec. It requires cables that exceed the USB specification. No seller ever specifies the resistance of a USB cable, but if you buy enough you find that some are very good and some are very poor.)
I guess the user community is quite diverse and there are different needs for the power supply. And those more into coding are not always very good in the hardware. There is a wiki page on thischrisryall wrote:. Why hasn't this been bottomed? If so, where? If not why not?
How long is the runway ?Douglas6 wrote:You could land an airplane in my apartment at night.