Arduino Forum

Using Arduino => Motors, Mechanics, and Power => Topic started by: jessabu on Mar 12, 2018, 03:40 am

Title: powering two dc motors and two servo motors
Post by: jessabu on Mar 12, 2018, 03:40 am
Hello. I'm trying to figure out how to power two servos and two dc motors for a robot project I'm doing. The servos are supposed to control long pieces of cardboard connected to some type of shovel in order to pick up trash. The dc motors are used for the movement of the robot. I read another forum post about powering the motors but I wasn't understanding something. My question is, can I power the motors with 6v, 4 AA batteries, or so I have to power them all with 12v? I appreciate any help given, thank you very much.
Title: Re: powering two dc motors and two servo motors
Post by: Paul_KD7HB on Mar 12, 2018, 05:49 am
Hello. I'm trying to figure out how to power two servos and two dc motors for a robot project I'm doing. The servos are supposed to control long pieces of cardboard connected to some type of shovel in order to pick up trash. The dc motors are used for the movement of the robot. I read another forum post about powering the motors but I wasn't understanding something. My question is, can I power the motors with 6v, 4 AA batteries, or so I have to power them all with 12v? I appreciate any help given, thank you very much.
To begin any help, we need to know the current and voltage ratings of the servos and motors, and especially the starting current needed by the motors.

Paul
Title: Re: powering two dc motors and two servo motors
Post by: jessabu on Mar 13, 2018, 02:21 am
Oh, I'm sorry about that. The servos are 4.8V-6V, and the DC motors are 3V to 6V. I'm not sure what you mean by starting current.
Title: Re: powering two dc motors and two servo motors
Post by: jremington on Mar 13, 2018, 03:10 am
The starting current, or the "stall current" in the data sheets, is the supply voltage divided by the motor winding resistance.

4xAA will power two standard hobby servos, but not more.
Title: Re: powering two dc motors and two servo motors
Post by: MarkT on Mar 13, 2018, 12:16 pm
You need to budget 1A per small servo, and probably about the same per small motor (although measuring
is better than guessing).  4 x D cell quality rechargables might be about right here, anything less isn't
going to handle 4A.
Title: Re: powering two dc motors and two servo motors
Post by: jessabu on Mar 13, 2018, 01:15 pm
Is 4A enough for the DC motors also?
Title: Re: powering two dc motors and two servo motors
Post by: MarkT on Mar 13, 2018, 02:45 pm
Perhaps you should reread what I said, it seems very clear to me.
Title: Re: powering two dc motors and two servo motors
Post by: jessabu on Mar 15, 2018, 03:57 am
Oh, again, sorry for the misunderstanding. Would 6 AA (1.5v each) batteries in a battery pack also work?
Title: Re: powering two dc motors and two servo motors
Post by: MarkT on Mar 15, 2018, 12:09 pm
Oh, again, sorry for the misunderstanding. Would 6 AA (1.5v each) batteries in a battery pack also work?
As I said, reread my answer, it hasn't changed and it addresses your power requirements very clearly.  4
quality D-cells.  4, not 6, D-cells, not A-cells, quality, not rubbish unbranded, rechargable, not alkaline.

Clear enough now?
Title: Re: powering two dc motors and two servo motors
Post by: jessabu on Mar 16, 2018, 02:56 am
Okay. Thank you for all of the help. It's very much appreciated  :)
Title: Re: powering two dc motors and two servo motors
Post by: jessabu on Mar 16, 2018, 04:13 am
I'm sorry. I have another question. If I use the rechargeable batteries, how would I connect them to the Arduino/robot? Through a power jack, or through a breadboard?
Title: Re: powering two dc motors and two servo motors
Post by: MarkT on Mar 16, 2018, 12:24 pm
Neither, the batteries are for the servos and motors only.
Title: Re: powering two dc motors and two servo motors
Post by: jessabu on Mar 26, 2018, 03:04 am
Okay, I purchased 4 D cell batteries over the weekend, but I'm still not understanding how I would connect the motors and batteries together. How would I connect them if not by breadboard or by the Arduino? Sorry to seem redundant, but I really don't understand.