Arduino Uno + 6 servos (Power Supply) ?

I need help on my robotic arm project. The question is i wanna use a seperate power supply for my arduino uno and servos. This means, i'll have two different power supply. Is that possible? What would you recommend for the solution? After done some reading, i  found 9v batt is enough for Arduino only. But for my servos? I dont know what to use, 4 x AA batt?
if each servos take 2 A x 6 = 12 A (so what would i do with this)?


Really need ur help! Thanks

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Nighter3D3 years ago

So you need to power 6 servos from a power supply. could you perhaps tell me what kind of servo you are using? 2 Ampere for a servo sounds kinda excessive.

Servo projects can have many power-sources. Standard batteries, rechargeble and quite often rechargeble battery packs used in RC stuff.

Anyway for a mobile device 4 AA for the servos tend to work just fine (considering that most servos are rated 4-6v and 4AA = 6v). 9v works for powering the logic, but with 9v being very low capacity you will want to only do logic with that power.

naqibzainudin (author)  Nighter3D3 years ago

Im using 2 servos Power HD 1501MG and 4 servos Power HD 3001 HB. So what is you reccomendation to replace 9V then ? @Nighter3D

So 2 "heavy" servos and 4 generic servos. the "stall current" described in their datasheets is the "peak" current. so when they are being resisted (stalled) by a high load they start consuming more. its the worst-case scenario and to be taken with a grain of salt.

4AA should be able to power them for a little while.

As for the logic:

the 9V battery can work for the arduino. just avoid powering extra stuff like leds from it. if planning to power by the VIN pin of the arduino then anything above 6.5v should work reliably. or if planning to power directly by the 5V anything between 4.5-5.5v works (~3AA)

naqibzainudin (author)  Nighter3D3 years ago

Do you have a better idea than 4AA? Do i need to get an adapter or etc?

iceng3 years ago

Besides whatever PSs you use to run your Uno & servos the Main thing that you must provide in your wiring is a Single Common Ground Tie Point.

That means joining the different Power Supplies negative side at one unique reference point where there is no chance of heavy servo ground return current spikes from disrupting the Uno's proper logic software operation.

naqibzainudin (author)  iceng3 years ago

Got it,

One Single Common Ground, and thats it right?

Yep !

That's how to join two or more power supplies.

Now .... you can appreciate optical isolators, No ground to worry about.

OPTOISO-Triac-Triac-sw.JPG