Power supply to control brushless motor?
 

Hi everyone!

I'm doing a school project testing out the performance of different micro-rotor designs, and wanted a little help understanding a few things and choosing parts.

The motor I'm using is this one:
E-Flite Park 250 Brushless Outrunner Motor 2200Kv

I'll probably be getting this ESC for it:
Turnigy Plush 12A

I plan to use an Arduino Uno or a Servo Programmer to control it. Seeing as I don't plan on flying anything, I was hoping to get some kind of power supply that plugs into a wall instead of a battery pack to power my motor. What are different things I can get that will be able to output all the voltage/current I need to test my motor throughout its full range? Would some kind of AC adapter to charge laptops work? Can it output the necessary current?

Also, I would like to know why ESC and brushless motors are rated at such high amperage. How can that little brushless motor and ESC I'm using be rated at 8A and 12A respectively without larger voltages to match? The big Tektronix variable power supplies are really powerful and expensive, but can only output like 5A.

One more question: I have a Jeti Advance 30A Plus ESC. Would I be able to use this for my little E-flite 8A motor?

Thanks in advance!

Any 12v dc power supply with sufficient amperage will work fine as a source.

Amperage is based on resistance and voltage with I=E/R (I is current, E is voltage and R is resistance.) so the lower the resistance the higher the. Current will be relative to the voltage. With a low enough resistance you can get 100 amps at 1v.

The rating on the esc is based on how much current can pass through it safely. The total current draw would be based on the motor as it is the true load in the circuit.

Thanks for the help!

What would "sufficient amperage" mean in this case? Also, if a motor is rated at 7A continuous, in what case would it ever actually draw 7A? (ie whats the voltage, power, load, scenario...)

An electric motor will draw maximum amperage at zero rpm and minimum at redline. The harder you want the motor to work will be the deciding factor. It you are trying to lift a cinder block off the ground, you will burn the motor out. Thats why we have gearing. It take the load off the motor but you have to sacufice something. That something it time or distance. It will take longer when you have your gear ration higher.

For example:
A 2:1 ratio means for every 2 times the motor spins, the output shaft of the other gear will spin once. It takes half the load off the motor but takes 2 full revolutions to accomplish the same distance or twice the time.

What is your "load" and what are you trying to accomplish. If you are running a propellor you will be fine. If you are trying to lift a brick, you may need some sort of reduction gearing to help.