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[on:]

Hello, I am about to begin my first
electronics project with an arduino Uno R3.
 After much research I am still a bit confused
on the circuit for the battery. I will be using
the arduino to control 4 micro servo's, an
LCD(with I2c back pack), and a HC-SR04 sensor.
 I know that I will need to run the power from
the batteries directly to the servos. Will I
also want to do the same for the other devices?
 I know I will also need to regulate the power
supply. I plan to use a 6v Nimh battery pack,
which leads me to my next question. I know the
arduino manual states 6v minimum input. I have
been told however, that I will want to use a
minimum 7.2v Nimh battery. Is this true?
 Lastly, when I make the battery circuit do I
want to run the positive supply to the
arduino's VIN pin? If this same circuit that Is
powering the devices is regulated down to 5v
before it reaches the arduino, will it be too
low to power it?
 I apologize for my confusion and I appreciate
all advice. I have attached a fritzing schematic to demonstrate what I have in mind.
 Thanks

[Reply #1 on:]

I know that I will need to run the power from
the batteries directly to the servos.

Yes, you will. The ground also needs to be connected to the Arduino.

Will I
also want to do the same for the other devices?

Not necessary.

I know the
arduino manual states 6v minimum input. I have
been told however, that I will want to use a
minimum 7.2v Nimh battery. Is this true?

6V in should be OK.

Lastly, when I make the battery circuit do I
want to run the positive supply to the
arduino's VIN pin?

I'd be a lot more comfortable connecting to the normal power in connector, so that the onboard regulator and diodes get a chance to protect the Arduino, just in case...

[Reply #2 on:]

Thank you for the information. My only other question was If i regulate the voltage from the battery down to 5v for the micro servo's/devices will I still want to run it to the arduino's regular barrel jack ? Seems like that would be double the regulation?

[Reply #3 on:]

Thank you for the information. My only other question was If i regulate the voltage from the battery down to 5v for the micro servo's/devices will I still want to run it to the arduino's regular barrel jack ?

I think not, and that is why they give you the 5v pin. I believe there has been information about this in  recent posts

Seems like that would be double the regulation?

Yes. It sounds harmless but I tried using a 5.3v 1000mA wall wart and it didn't work too well.

[Reply #4 on:]

Hence the 'dropout voltage' rating for the voltage regulator.

Don