# How Much Voltage Should I Use

I'm working on a small robot that will be using 2 continuous rotation servos that each require 6v to operate. Now my question is should I hook both up to a single 6v power source OR hook both up to a 12v power source OR hook each servo to its own 6v power source? Hope someone can help me, thanks!

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Consider hooking up the circuitry and "brains" of your robot to one voltage source (3.3 or 5V depends on system) and your servos to another one 4.5-6V. This will eliminate noise in your system and may help you avoid some common problems that people have when starting out. This is not necessary just a tip.

The phenomena this avoids is back-EMF from motors (basically motors are noisy and cause your power rail to jump up and down, this could be potentially bad for a microcontroller like an arduino and make it not behave how you want it to).

Yeah I'm going to be using an Arduino UNO and I'm going to have that powered by a 9v battery. Then I'm going to have my servos connected to a separate 6v power source. Thanks for the tip and explanation!

They will each get 6v and the total draw (current) will double. Do a google for series/parallel and you can see what I am talking about --there are a million tutorials out there for this one.

Awesome, thanks!

I of course agree with chris since he helped me with the same problem. He is right about looking at a series/parallel diagram. It helps once you study it and think about it. I had been also using servos but with a Parallax Propeller and since that chip takes in 5 volts and converts it to 3.3 v. I took found the row of pins on the breadboard with the 5v and used a wire to transmit that current to te servos. The 5v worked well.

So when I hook them up to the same power source (say 6v) they'll each get 6v? Or will the voltage "split" or is that not possible?

And yes I'm aware of that, they will be seperate.

They should be wired in parallel to a 4.5v-6v source. (The signal wires should not be connected together unless you want both of them to move the same way)