Basic "using external PS when powering servos" question

Other Hardware Motors, Mechanics, Power and CNC
1

Hi all,

As you'll soon find out, I'm still new with Arduino (more of a software development background) doing a small project in which to control a scaled model of a 'laser turret' (to be used in a small movie). The final model will use three servos controlled by my Arduino Mega and a Nintendo Nunchuck (already have everything working for 1 servo and waiting for someone to finish a mock-up of the turret with all servos included).

I do know that I need to use an external power source to power the servos (don't have their specsheet here), so I want to use the following supply that I have: http://www.velleman.eu/distributor/products/view/?id=381092.

My question is, I'd like to power both the Arduino and the servos using this supply. If I connect the supply to the Arduino power jacket, I assume the 5v output still gives me +5v? But if the three servos are working simultaneously on the +5v connector, all current will be drawn through the Arduino probably causing some heat issues? Should I thus create two lanes from the power supply to (1) power the Arduino and (2) power the servos?

If there is anything unclear, please let me know! I'll update with servo details once I get home. Thanks!

2

Simplest solution is to use servo motors that need 12v so that you don't need to drop the supply to 5v for them. But if you do want to use 5v servos, you will need to provide a separate 5v regulator for them because the Arduino regulator won't provide enough current.

3

Thanks for the quick reply!

So I could connect the power supply directly to the Arduino power jack and access the 12v through the Vin pin, right?
Then I should convert that to 5v for the servos using a regulator like you said. Could you please provide a hint into what (kind of) regulator to use?

edit:

I think I might have a standard 5v regulator (something like this: http://www.drbit.nl/index.php//Components/Active-Components/5V-Voltage-Regulator/p_38.html). This gives me one more question, should I put this regulator infront of the Arduino (thus providing +5v to the board) instead of giving the Arduino 12v? Or might this cause fluctuations depending on servo usage etc.