Asked — Edited
Resolved Resolved by Dunning-Kruger!

Powering Ezb4

Hello Everyone, I recently received my EZb4 in the mail. After days of trouble shooting, browsing the forums, and reading the manual I still cannot solve this problem.

I am trying to run a single servo on my EZB4. I am having trouble with the power.

4.8v - 6v servo

Here is a list of power sources I have tried;

  • 11.1v Lipo Battery, it worked for powering the EZB4. After using the servo for a few minutes it but burnt out the servo.

  • 4 AA batteries, The EZB4 continually shouted "My battery is low." I turned off the battery monitor and it still said this.

  • DC Power supply on voltages from 5v - 12v, on the lower voltages (under 7.4v)the EZB4 shouted "My battery is low." The higher voltages the EZB4 powered on correctly. I didn't power the servo with the higher voltages because I didn't want to burn out another.

  • 6 AA batteries, the EZB4 didn't sound it's power on chime but only showed a solid red light.

Can someone please help me find an adequate power source?


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Belgium
#1  

3S (12.4v) lipo is clearly a no-no with a 6v servo. Same for 6 alkaline AAs (9V)

More over, regular alkaline aa batteries can not provide sufficient peak current. As a result when the servo draws too much current, the voltage will sag and the ezb will complain. However, you can adjust the low voltage warning in ezb, and you should set it to 5V or so when using 4 aa bateries and for a single servo, your batteries might manage. It still advisable to get NiMH rechargable batteries

The powersupply, if it can provide 5A or so, would be ideal. Set it to 6v. You just need to modify or disable the low battery warning

#3  

Ok I think I'm going to use a voltage regulator. Also, I check into the amps for the power supply.

Thanks for the help!

#4  

Bad advice @nomad... as I mentioned before in a few past threads ez robot's voltage regulator is meant for low power devices like ultrasonic sensors... It can only output a max of 1Amp~..... Regular sized servos need about 3-4amps (peak) to run (which depends on the load on the servo).

PRO
Synthiam
#5  

First advice of any product is to read instructions and follow tutorials - with robotics and electronics, doubly so:D. You will find we put a significant amount of effort into the learn section. The most useful document for you to read related to power is the datasheet, here: https://synthiam.com/Community/Tutorials/18?courseId=4

I would recommend starting at the beginning, like the manual states, and follow through the tutorials to get started. Once you know what you're doing, it'll be amazing how quickly you can build things with the EZ-B and ARC. Have fun:D

#6  

@DJ Sures

I have read the entire learn page, including the tutorials for Powering your EZB4, servos, and the lessons on voltage, resistance, and amperage.

I still cannot find the answer.

I bought 3 10k ohm resistors to use with the Lipo Battery to lower the voltage to 5.5 volts. This is the formula I used: r2 = (Vout) (r1) / (Vin)-(Vout)

According to the formula 30k ohm resistance would be the right amount to limit the 11.1v to 5.5.

I wired up the resistors but when I plugged the battery into the EZB4, in the debug terminal window, it said EZB4 voltage = 12.6.

Can you tell me the type of battery I need to power the servo.

I switched from arduino to EZB4 because I was under the impression that information.ike this would be readily available in the instructions.

Any help is great appreciated. Thanks:)

Belgium
#7  

first of all, if you just put the resistors in series, they will not do anything to the voltage, they will just eat up your batteries. That formula of yours only works when you build a voltage divider: http://www.learningaboutelectronics.com/Articles/How-to-reduce-voltage-with-resistors.php

But thats NOT how you want to do this. Those resistors in a voltage divider will convert the excess voltage in to heat and will most likely burn out if you bought regular resistors which can only dissipate a a fraction of a watt at best. Which is not nearly enough. Even if you use some high wattage resistors with heatsinks, you will just be heating that up for no reason and dramatically reduce battery life.

You need a voltage regulator, often called BEC for remote control use. And a beefy one at that, depending on your servos. Or you need a battery/powers supply and servo that both operate at the same voltage.

#8  

@Robotist_in_training ... I use a 6V SLA (lead acid) battery or a 6V nimh battery pack when using lower voltage rated servos like the one(s) you are using... You can disable the low battery warning in two places... One in the connection control settings (usually the first control on your desktop of ARC) and also in the ezb4 web server.... Disable it in both places...

PRO
Synthiam
#10  

Unfortunately you’re attempting to build a robot with sensors, servos, and components on an incorrect power source - and blaming everything else except the battery:D

Simple math... if you added up the number of items in your robot that require 5-6v and added up the number of items that require 12v, you will find the ratio is leaning toward 5-6v power source.

Rather than trying to wedge a 12v power source into a 6v robot, I recommend using the correct power.

Modifying voltage is not easy - because there’s not many effective ways to do it for motors. Most Voltage regulators are wasteful, because they generate a TON of heat, which is wasted energy. While you could wire a 3-5 amp regulator to each servo, you’ll find that being a comical effort vs replacing the battery.

Get yourself a 7.4v lipo because ezrobot servos are compatible with that. Otherwise get a 6v Nicad for other servo brands.

Then you’re rocking:)