12v converter and amps

Discussion in 'The Projects Forum' started by mikefree, Mar 1, 2014.

  1. mikefree

    Thread Starter New Member

    Mar 1, 2014
    Hi. I know zip about electrical (as you can tell from the questions) so if you have an answer please speak in grade 9 english...and talk slowly :)

    1) What is the difference between the big (ish)110v to 12v converter from canadian tire for 50 bucks and the much smaller 1 dollar one from ebay? Isnt every ipod and phone charger a 110 to 12v or 5v converter and they are tiny and cheap like the ones on ebay. I have a tone of them around the house as well from old toys etc that say input 110v and output 12v. I looking to power some leds for home power and maybe a case fan.

    2) Amps. if the led appliance uses 2A but the converter puts out 14a will it damage the appliance or does that work the other way around.
  2. MrChips


    Oct 2, 2009
    The fundamental Ohm's Law applies which states that I = V/R,

    the current I through a resistor is proportional to the voltage V applied across the resistor and inversely proportional to the resistance R.

    This means that the load is going to demand as much current as it needs based on its resistance.

    See this thread:
    #12 likes this.
  3. antonv


    Nov 27, 2012
    That is to say you always want your power supply to be able to supply more current than your gadgets will need, otherwise the gadgets may damage the power supply or at least blow a fuse.
    mikefree likes this.