# ac12v 500mA or 3000mA?



## hi hi (May 21, 2008)

hi,
im trying to buy an adapter for my device which reads it needs a AC in 12v - 500mA. the adapter I have is the same except it has 3000mA. does more mA equal more stability? or will it fry my device? i don't think so because its the voltage that would do this right? any knowledge of this kind of thing would be very grateful.
thank you.


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## octaneman (May 13, 2009)

Hi hihi 

Milliamperes on batteries or chargers means that a battery or charger will supply 500mA for 1 hour, it doesn't mean stability, as for voltage think of it as water pressure inside a pipe. If the pressure (voltage) is lower in the adapter, then it will cause the device to drain it faster because there is not enough charge to sustain it. If the amperage rating were higher, then it would cause the device to burn. The basic rule to apply here is Ohms Law where E= I R. For example: Suppose you have a battery that needs charging. A charge is built up in a battery if the current is pumped into it slowly, if it is done too quickly, the battery heats up fast and it burns out.


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## DonaldG (Aug 23, 2007)

Put simply, the 3000ma device will be fine. Go ahead and use it.

It will supply UP TO 3000ma. Your device will take only what it needs. IE: less than 500mA and that is all the device will take from the power supply.


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## Done_Fishin (Oct 10, 2006)

I agree with Don .. the device will only ask for what it needs and the supply will also stay cooler since it doesn't need to go to limits!!


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