wsrussell
USA
Asked
— Edited
I purchased the Developer kit in hopes of trying out the Teddy Ruxpin project. I have the EZB v4 powered by the 6 rechargeable batteries like recommended; however, if I attach a servo to it, it will reboot if the servo attempts to move more that a few degrees. Is the rechargeable batteries only powerful enough to turn on the EZB? Do I need something else to actually run the servos that comes with the kit?
I share your pain, i started with a basic kit and NIMH batteries.
short answer:
1) If you want to run from battery, you will need a Lipo Battery:
http://www.ez-robot.com/Shop/AccessoriesDetails.aspx?prevCat=103&productNumber=41
LiPo Battery Balancer Charger:
http://www.ez-robot.com/Shop/AccessoriesDetails.aspx?prevCat=103&productNumber=42
And a Dean to DC Barrel connector:
http://www.ez-robot.com/Shop/AccessoriesDetails.aspx?prevCat=103&productNumber=103
If you want to run from a power supply:
you can get one of these:
http://www.trcelectronics.com/7.5-volt-power-supplies-chassis-1.shtml
but you will need more than 20 Amps, if you have plans to add more servos in the future. Also you will need to add a power cord.
I have this one:
http://www.trcelectronics.com/View/Mean-Well/RSP-200-7.5.shtml
fan-less.
I'll post more details why the developer kit battery pack does not work with the EZR servos.
Thanks, that is exactly what I was looking for. I still have a lot to learn. Wish I knew that I would have needed the parts when I ordered the dev kit as the shipping is as much as the parts. Guess I will also be looking at trc electronics now. I have spent some time going thru all of the tutorials and been reading/searching the forums since getting the Dev Kit. The tutorial were pretty good for using/build the robot kits; but not much on the Dev Kit. I was thinking that the Dev Kit would be a great way to start with a small project, using a few servos, and doing just some basic moves and learning how to use the various components. Back to ordering parts and waiting...thx again...looking forward to your post on the details...
6 x AA Battery Holder (Included in the developer kit):
http://www.ez-robot.com/Shop/AccessoriesDetails.aspx?productNumber=15
Code:
Lipo battery:
http://www.ez-robot.com/Shop/AccessoriesDetails.aspx?prevCat=103&productNumber=41
Code:
The relevant difference between a Lipo and NIMH battery is the discharge rating:
the above Lipo battery can provide (discharged) at 25 x 1300 ma = 32500 ma
a NIMH battery can provide (discharged) between 1x and 1.3x 1900 mA = 1900-2400 ma
if you try to pull more mA than the max discharged valued, it will cause a brownout (battery voltage will drop) .
if you don't go with a Lipo Battery, you will need to choose a good power supply (10-20 A).
I had the same battery issues and someone mentioned 1.5A per servo, so i tried a power supply 7.5 2A, and i was surprised didn't work. The servo had no load and i got a brownout ?
I decided to measure the EZR servo current:
Idle <= 40 mA
Continuous sweeping <= 400 mA
Initial Peak/Burst = between 1800 mA and 2600 mA
Every servo is different, i tried other servos and the initial peak is near the operating value (400 mA - 600 mA).
To summarize if you are using the EZR servos, you will need a Lipo battery or a good power supply, the main culprit are the consumption peaks.
More info:
https://www.ez-robot.com/Tutorials/UserTutorials/162/6
https://www.ez-robot.com/Tutorials/Lesson/26
https://www.ez-robot.com/Tutorials/Lesson/13
http://rogershobbycenter.com/lipoguide/ (HTTP not HTTPS)
Thank you very much for the details. This helps a lot!