Servo Power Supply

Hello!

I'm not entirely sure I understand how to setup a power supply for my servos...

Would this be feasible? I don't want to break anything trying to set it up and I'm afraid of starving the servos and damaging them. 2 AA for each servo and they are 9g microservos.

If more details are need please ask.

Thank you

Can you instead use 3x AA batteries for a higher voltage? I dont know if you can drive a servo with 5v while supplying only 3v to it.

liudr:
Can you instead use 3x AA batteries for a higher voltage? I dont know if you can drive a servo with 5v while supplying only 3v to it.

So instead of having two 2xAA Battery packs have two 3xAA Battery packs?

Three can usually reach about 4.8V when full. I did some digging on adafruit. There seems to be only one voltage mentioned on servo motors, so I think control and power voltages should be the same or close. Anyway, higher voltage should provide more torque, probably close to the torque on it spec sheet.

Awesome thanks!

Most servos that I have used work between 4.8V to 6V. So assuming you have 1.5V batteries, I would recommend using a pack of 4 batteries ie. 6V in parallel to each servo.
The important thing to consider with servos is current. Servos, when under load, consume a lot of current so make sure your batteries can provide enough current.

reshampanth:
Most servos that I have used work between 4.8V to 6V.

Unless you know otherwise, I think it's safe to assume the above voltage range is safe.

There are lots of threads discussing power multiple servos. Here are a couple.

DuaneDegn:
There are lots of threads discussing power multiple servos. Here are a couple.

Yeah sorry. I did do a lot research before posting (maybe I was searching wrong). I didn't know if there was a recommended AA battery to servo ratio or something, so I wanted to ask if my setup looked right

Acais:
Yeah sorry. I did do a lot research before posting (maybe I was searching wrong).

No problem.

My intention was to help not criticize.

My curiosity. Does anyone have spec sheets explaining the relation between power pin voltage and logic pin voltage, or are we pretty much using 5V for logic all the time? I only have a couple of servos from adafruit. No data sheets.

liudr:
My curiosity. Does anyone have spec sheets explaining the relation between power pin voltage and logic pin voltage, or are we pretty much using 5V for logic all the time? I only have a couple of servos from adafruit. No data sheets.

I don't have documentation to back me up but I've used a lot of servos. Hobby servos would use the same logic as used by a RC receiver. These are normally specced to run from 4.8V to 6V. It's seems safe to assume the voltage requirement was to keep 5V logic chips happy.

I think it's also safe to assume the servo uses 5V logic chips.

Most of my servo projects have been done using a 3.3V microcontroller. The only time I've had trouble using 3.3V logic with a servo is when I've used a resistor on the signal line. Without a resistor, all the servos I've used (I think I've getting close to having used 100 servos (but only a dozen or so different models)) have worked fine with 3.3V logic.

5V logic should be fine whether or not you use a series resistor.

Thanks DuaneDegn. I imagine 100 servos can motorize lots of parts. Must be fun.

liudr:
Thanks DuaneDegn. I imagine 100 servos can motorize lots of parts. Must be fun.

"Fun" is too mild a word for what it is. I always thought I'd like to do this sort of stuff but once I finally started using microcontrollers I realized I had grossly underestimated how much fun it would be.

Here's my first project using lots of servos. As you can see, it didn't work very well. It was still a lot of fun though.

It turns out using a kit can make this sort of thing a lot easier. One of my more recent servo projects turned out a bit better. Using a frame purchased off ebay was a big help.

The last example used 22 servos. The most servos I've had going at once was 32. Most of the servos in the 32 servo demo ended up being used the two hexapods mentioned above.

A lot of people struggle getting power to lots of servos (myself included). Once the power issues are solved then work can start on the really hard (and really fun) part, programming.