I'm working on my very first project ever and have a basic question. I using an Arduino Uno 3 and a single 25KG servo. The spec for the servo says "Working Voltage 6.0-7.4" I've connected the servo to the 5v pin and it seems to work fine but I believe this would be under powered? Keep in mind, the servo won't be doing anything intense or fast. I am using it to rotate the head of a mannequin about 15-25 degree at random intervals.
Would using the USB cable to the Arduino board supply enough power? If not, I can use an AC adapter an plug it into the Arduino board but I'm not sure if that is the correct approach. I've seen some 9v AC power adapters but since the specs for the servo say 6.0v-7.4v would it then be overpowered?
I don't want to use batteries as the goal would be to have this running 8 hours a day; 7 days a week.
9V DC could damage the servo. It is never a good idea to ignore specifications.
When deciding upon a power supply for any motor the first thing one must specify is the voltage.
The next is the stall current (locked rotor current) of the servo. The servo will draw that current, briefly, every time that it starts and a servo trying to maintain position can start a lot.
Your servo has a locked rotor current of 3.6A so USB (500mA max) is no good. No Arduino on board regulator will handle that either.
So a mains powered supply 6V to 7.2V DC and 5A or so to give the supply some overhead.
Connect the external supply ground to Arduino ground as well as servo ground.
Remember A Power Supply the Arduino is NOT! Connecting servos, solenoids, motors and other inductive loads to the Arduino usually frys it. You need an external device to drive inductive loads such as a motor controller, transistor, MOSFET etc.
I've been watching some more tutorials. Would using a MB-102 breadboard power supply and a 6v 5a DC wall plug connected to a breadboard be the right approach?
Power the servo directly from the 6V 5A supply. Connect the power supply ground as shown in post #2.
Use the breadboard supply to power 3.3V or 5V peripherals of the Arduino.
Do not power the servo from the breadboard power supply. I can't find a current capability specification for the breadboard power supply but I doubt that it will gracefully handle the 3.6A stall current of the servo.
Nice power supply. I have one like that out of china for about a buck but It does not work very well with 6V because of the drop out of the 5V regulator, the 3V3 is fine. 7V or more it is great.
