Ez-b V4 - Servos And Power Supply - Questions - Community

69developer

USA

Asked May 2015 — Edited May 2015

Ez-B V4 - Servos And Power Supply

Is there any documentation on how much power/amps the EZ-B V4 will supply for servos?

I see a lot of you are using up to 20+ servos (and some are the big hobby ones) and was wandering about how you handle the power for the servos?

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Dunning-Kruger

Canada

#1 May 2015

Yep... all the specs are in the EZB4 PDF in the learn section....

EDIT ***5 amp continuous/board with spikes up to 20amp***
One of my ezb4s is driving 20 + servos on my inMoov

See here... EZB4 Data sheet

Jeremie

PRO

Canada

#2 May 2015

I know it has floated around the forum that the digital power pins can handle 5 amp per digital pin, but that's not the case. It's max of 2 amps per pin and a combined constant amperage of 5A for all the digital power pins. While you can have a spiked (pulsed) current up to 20A, the ez-bv4 is only rated for 5A of constant current.

If you find you are drawing much more than this we would recommend externally powering your motors directly from the battery power supply to the motor drive electronics (it's good idea to add a fuse in between them).

Servo power is best to come from a 7.4V LiPo battery (with protection) but you'll need servos that are rated for 7.4V, if you don't have servos that can handle this high of a voltage you'll need a
voltage regulator.

The thing to watch out for with regulators is how much current draw they can handle, like most motors, servo motors can draw huge spikes of current when first initialized so you'll likely want to double or triple the current rating of your voltage regulator compared to the operating current of the servo so you don't experience a brown out. Brown outs result in the voltage dropping below a certain level and will either effect the operation of the servo or the electronics controlling them.

Dunning-Kruger

Canada

#3 May 2015

Thanks Jerimie... I'll remember that...

I guess I need to re-read the EZB4 data sheet myself....

Jeremie

PRO

Canada

#4 May 2015

No prob @RR figured I'd mention it just to clarify. Thanks for editing your post!

Dunning-Kruger

Canada

#5 May 2015

I have had my inMoov's 10 of the 12 giant scale 805bb servos move all at once ( and under load too) and the ezb had no issues with it... It's not easy to hit the power "wall" of the ezb4, but if you find that you are, the solution is easy... Just use a second ezb

69developer

USA

#6 May 2015

Thanks for the details Jeremie and Richard.

Somehow I missed the datasheet, and thanks for direct link.

I'm currently using a Phidget servo controller on my prototype build platform and want to try the EZ-B controller. Will be moving this arm to a SuperDroid platform soon.