On 25 January 2013 18:06, Anthony Anson tony.anson@girolle.co.uk wrote:
Read the spec.
That only works if you believe the spec.
The problem I have now is that I have a mixture of chargers, most of them "branded", some of which it is become clear are likely fakes, but without a way to know which are which I don't know which to trust. (Eg I have a mixture of Sony Ericsson chargers, a least one of which is genuine, but if any are fakes I can't tell them apart.)
It's the voltage which determines the speed of charging, not the rated amps
- but if the amperage at the required voltage isn't sufficient to cope,
either the delivered voltage will drop, or the supply will lose all its magic smoke.
So puting it another way: if a PSU says it can deliver 1A @5V, then I should be able to stick a 5ohm (R=V/I) resister across the terminals and the voltage shouldn't drop substantially below 5V? And provided I pick a suitable 5ohm resistor (5W? P=VI?) then I shouldn't get any loud bangs, burning smells, or tripped power?
Not really. Just choose the supply which delivers enough and then a bit.
The problem is I have picked supplies which *claim to* deliver enough but I don't believe them. Not least I'd like to prove they don't and get me money back!