Iphone charger, 1A.

Hello
I have a Iphone 3Gs with the original Iphone charger.
On the charger it says that it supply's  5V,1 A, and a normal computer usb-port supply's 5V,0.5 A.
Is it safe to use my mp3player with the Iphone charger?
On my mp3 players charger it sayd 0.5 A but I lost it.

Can my mp3 player's battery break if I use double the current that is recommended?

Question 2: If I buy those Iphone chargers on ebay, is it safe to use them on my Iphone?
cgi.ebay.com/ws/eBayISAPI.dll

Question 2: If I leave my charger in the outlet will it still draw current?
Without any devices attached to it?

Comments

[steveastrouk]

You can use the supply, it will only supply the current your appliance needs, if the voltage is the same

[Popstickal]

Ok, so I can use usb devices that uses everything from 0-1 A?
If its still 5v.

But iphone chargers also send some volt on the data pins.
Is it harmful?

Thanks.

[steveastrouk]

They can't send out more than USB voltages.

[Popstickal]

Ok, theoretical if I have a power source that supply's 5V but 20A, would it still be ok for my Iphone?
Does the Iphone only draw a certain amount of current that is needed for it to charge or will it blow up?

[steveastrouk]

Yes, it only draws what it needs !

[Popstickal]

I'm sorry for asking you all the questions but I have one more.

If a use a nokia charger that output's 9V, 500 mA.
If I use a 7805 voltage regulator will it become just lik a computer usb-port?
5V,500mA

[steveastrouk]

Yes !