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EZ-B V4 Servo Issue

Hi guys,So I've just bought my first EZ-B v4 to use with my robot to control the servos however I'm having some serious issues.

I tried connecting just one servo motor to the ezb using the signal from the ezb and a separate 6v power supply to power the servo. I added a horizontal servo control within the software and set the min and max angles to 80 and 120. The issue is that no matter what angle I try to go to the servo turns all the way left until it hits its limit and keeps trying to turn until it burns the servo out.
I tried a different servo and tried different angles and even tried to invert it thinking it would change the direction but it keeps turning left. 

I've now lost 3 servos and have no idea what's going wrong.

Any ideas? Have I got a faulty ezb that is destroying my servos?


Related Hardware EZ-Robot EZ-B v4
Synthiam
#1  
Hey Radium - a few questions

1) Did you disable the low voltage monitor? I'm guessing you must have because the "My battery is low" on 6v would have been annoying:) And the servos won't move at all with power below the threshold

2) What servos are you using at 6v? Depending on the servo, it might not be able to accept 6v and it's behaving strangely

3) Do you have a volt meter to ensure the voltage coming from the power supply is indeed 6v? If not, you can add the EZ-B Info control to see. Check here: https://synthiam.com/Software/Manual/EZ-B-v4-Info-16059
United Kingdom
#2  
Hi DJ Sures,

Thanks for your reply. I'm running the ezb on a 7.4v supply and the servos on a separate 6v supply. I measured both and they do measure the correct voltage. I'm using hitec hs-85mg servos. The issue is that as soon as the ezb sends it a signal to go to a position (90 in this case) the servo just turns all the way to the left and hits the stop and keeps trying to turn until I stop it or the servo burns out or in one case something inside snaps and it just spins continuously. I'm not worried about plugging any servos into it due to them costing 26 each and I've lost 3 of them now.
Synthiam
#3   — Edited
Do you have a common ground across both power sources? Meaning, the servo power source GND is connected to the EZ-B power source GND?

I recommend using one power source, not two. That would surely remove one of the possible problems. You can disable the voltage monitor on boot-up in the web config menu of the EZ-B. And again in the Connection control for the project in EZ-Builder. Use the 6v power supply once the voltage monitor is disabled.

If you connect a servo to the EZ-B, it only needs to be connected for a second and if it moves all the way to the left, disconnect it. The servo won't burn out that quickly, even for a hitec. You know, the EZ-Robot HDD servos will blow the doors off those hitec's (and most hitec's are knock-offs anyawy)... The EZ-Robot servos are cheaper, quieter, stronger and have built-in stall protection. I'd check them out for your next robot purchases: http://www.ez-robot.com/Shop/AccessoriesDetails.aspx?prevCat=9&productNumber=7

Even though I can't think of a possible way the EZ-B could send a signal outside of the servo PWM range, you can always contact EZ-Robot and have it returned under warranty.
United Kingdom
#4  
Hi DJ Sures,

Thanks for the suggestion, I disabled the voltage monitor and ran the EZ-B and the servos using the single 6v input and everything is now running correctly. The issue must have been that I didnt have a common ground between the two input voltages as I didnt think that I would need was as the EZ-B was only providing the signal for the servos, lesson learned. The issue i am now having is that the EZ-B keeps resetting when all the servos move (currently 10 servos).

It shouldnt be a power issue as my previous set up used the same power supply with the same 10 servos but it ran using an Arduino. I may have to have a seperate power line for the servos, should this work if I use a common ground? The problem is that I am using the EZ-B on my Johnny 5 build so I have to use these 6v servos. I think I saw in one of the tutorial videos that a seperate power supply may be needed to power the servos but no instructions on how best to do this (at least that I can see) I am still very new to the EZ-B, it looks fantastic, I just need to get it running as i need it.
Synthiam
#5  
Great to hear:) 

The disconnection is power related. 10 servos will draw a lot of current.