Discussions

Two ESC with BEC, two batteries and one RC channel result's in problems

Posted by Gerd Ulbers on July 24, 2014 at 1:22am

Hi,

I got a problem, perhaps somebody is able to help me. I made the following configuration:

3691139650?profile=originalIn this configuration only motor 1 is running. When I disconnect the lower power supply motor 2 is running. Why is this happening? I use 4s batteries, 20A ESC Model 30020 and A-2830/12 motors.

Thank you for any response,

Gerd

You need to be a member of diydrones to add comments!

Join diydrones

Tags: esc, problem
Email me when people reply –
Follow

Replies

        • Gerd Ulbers > Joe Breznai July 24, 2014 at 11:16pm

          Hi Joe,

          I got the graphics here:

          http://2bfly.com/knowledgebase/electronic-speed-controls/multi-engi...

          The ground in my case is connected by the common ground of the power supplies. So in fact the ground of the power supplies should be shown connected. To connect additional grounds creates ground loops.

          Gerd

          • Scott Reid > Gerd Ulbers July 27, 2014 at 7:18am
            I would second Joes opinion. The second ground is definitely required. I'd begin by swapping escs to see if the problem follows.

            Also, once both grounds are connected as needed, you will need to recalibrate the escs if you originally did it without the signal ground on one of them.
            • Gerd Ulbers > Scott Reid July 27, 2014 at 8:36am

              Hi Scott,

              Like I said in the reply before the ground of the power supply is connected. So I don't see a need to connect both grounds of the BEC's, because both grounds in the ESC and BEC are connected.

              Am I right?

              Here is the correct layout:

              3702869614?profile=original

              • Scott Reid > Gerd Ulbers July 27, 2014 at 9:08am

                I would not assume that the battery negative is the same as the BEC ground.

                On a somewhat related note, I would consider connecting the batteries in full parallel; i.e., tying the +s and -s together (with high current wiring/connectors).   This is how I usually do multi-battery setups, and I think it's most common.

                To diagnose this, I'd selectively remove and swap components to identify the issue.

                Start by simplifying the circuit by using just one battery powering both ESCs, and  connect both signal grounds.  

                Swap ESCs - does the problem follow the ESC or the side of the Y connector it's connected to?   If it follows the Y connector, than that is the problem.   If it follows the ESC, then that or the motor is the problem.  Swap Motors in that case to determine if it's the ESC or the motor.

                • Gerd Ulbers > Scott Reid July 27, 2014 at 11:46pm

                  Hi Scott,

                  "I would not assume that the battery negative is the same as the BEC ground"

                  If you measure the resistance it is 0. So according to my opinion it is connected.

                  I tried all your other proposals but there was no effect.

                  I think that it may be necessary not to connect the radio receiver directly, instead using two optocouplers with an y adapter. May be that helps. But the question is if one channel of the radio receiver can drive two optocouplers.

This reply was deleted.

Activity