Originally Posted by max90272

Hi there,
I'm having trouble interpreting readings from various power supplies. For instance, if you have a 12vdc, 2amps power supply, does that means that this particular model can handle motors or units that draw UP To 2 amps? In other words, does the rating on the power supply represent the MAXIMUM that this power supply can deliver?

Yes it means that the power supply can supply any amount of current from zero to 2 amps. The motor design (it's resistance) determines how much current it draws from the power supply. If it draws more then 2 amps then the power supply is at risk.

What if I use a 3amp power supply for a small motor that needs only 500ma, will it make the motor run badly, or will i burn it?
The motor will run fine, 500ma is within the range that the power supply can handle. Again the load (the motor) determines the amount of current drawn from the power supply.
I have the same question for readings on motors. If i have a step motors that has 3V , 3A readings on the back, does it mean the motor needs AT LEAST 3V and 3amps amps to run well. What if you supply more voltage?
That is the specification that the motor was designed for. The motor probably could work ok with somewhat lower or higher voltage depending on load, enviroment, etc, but it's always best to go by manufacture's ratings
thank you for all your help on these VERY basic questions.
Study on Ohm's law until you have a good understanding of the relationship of V,I and R would be helpful for you I think.
MAX