Question about electronics

[NachT]

I'm no good at electrical stuff so thought I'd ask this quick question!

I've got a device (USB Hub) that I need a new power adapter for, as the current one has too short of a wire attached. The current power adapter for the hub has an output of 5Volts and 4Amps.

I'm having difficulties finding a power adapter with exactly the same output, can I use a power adapter which has an output of say... 5Volts and 1Amp?

I'm also curious to know if it would be safe using a power adapter that gives an output of more Amps than required, say I had one that outputs 5V with 8A, would this cause any damage to the USB Hub? (I'm thinking along the lines of, the output Amps are an 'upto', i.e. upto 5Amps output? Or am I wrong in thinking this way?)

So, would I cause any damage, or what would be the affects of using a higher or lower Amps output than required?


p.s. I'm also curious, if anyone knows, how a power adapter can have an input of say xx Volts and 0.8Amps, then have a higher Amps output than the input? (Or does it just convert the V's to A's? )


Probably a stupid question, but I had to ask. Found nothing on googles

 

[NachT]

Thanks for the fast replies guys

The hub will be used primarily to charge devices up (iPhone, Blackberry, etc), thus needing the extra power (and not requiring to be connected to a PC).

I do have a soldering iron, but I don't know if I trust myself to try and extending an electrical cable that carries to many volts!

lurkio, you mentioned if I was going to buy a new adapter to make sure it is 'at least' 4A. Would a higher amp adaper, keeping the same voltage, be just as good, or cause any damaged? (Just to try and make my quest easier to find more available adapters).

 

[NachT]

I've also got another question about this,

Are there such things as extension cables for these type of connections? i.e. can I buy a sort of rounded-off circular connection to just extend the adapters cables length? Looking at the connector, it looks like a 3mm diameter.


Cheers