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Direct Servo/BEC wiring diagram help: Does signal wire require ground?

STANG KILLA SS

~THE SCALE SHOP~
Joined
Apr 20, 2006
Messages
10,058
Location
KILLEEN TX
ok. on my scale trucks.
i have steering servo (HV), and a winch servo (heyok controller strictly limited to 6v old version)

so i want to directly wire my steering servo to a external BEC(HV), and let the ESC BEC power the Rx and winch servo(6V).

is this possible?

so i want to make one of these so i dont have to cut the servo or BEC leads.
ansk.jpg


cgh7.jpg



Here is the diagram i came up with.
jffs.jpg

*is this correct?

*does the signal wire require the ground that goes from the "G" to the RX? or does it only need to go from the BEC to the Servo? the adapter above goes to all 3 it appears.

* on the adapter above the signal appears to come from one of the plugs that are glued together but the ground comes from the other plug. but theres a jumper between the two. so does the origon of the ground from either glued end not matter? because of the jumper?

*since i will have "two" becs running, is there any chance of any kind of back power feed threw the signal wire/ground back to the rx threw the adapter/diagram above? does having the ground wire from the "G" to the RX affect this answer?

thanks!
-Cory
 
You're exactly right to think of it as another BEC because thats what it is. If you're only running six volts you could just run it through the reciever and be fine (if the power wire from your esc is disconnected). Otherwise your diagram from the servo side looks great (I used to run that exact setup). I always prefer to run a ground to the receiever.

Also:

* on the adapter above the signal appears to come from one of the plugs that are glued together but the ground comes from the other plug. but theres a jumper between the two. so does the origon of the ground from either glued end not matter? because of the jumper?

On those adapters the ground is shared between the BEC, the servo and the ground that goes to the reciever. So yes.
 
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its always a good idea to keep the ground connection along with the signal.

in circuits that are interconnected the gnd connection between each individual circuit helps to act as a voltage reference point between them whether they are individually running seperate power or shared power.

in one of my circuits i make the microchip side runs one voltage and the other half runs at 3s voltage, the gnd connection between them is the reference point that allows trouble free operation between the two.

most bec circuits that people will run in their rigs will be run from the same power source so you can avoid that gnd connection with the signal wire but ideally it should be included as it makes it one less culprit when somethings not working right and its time to troubleshoot


tony
 
so i want to directly wire my steering servo to a external BEC(HV), and let the ESC BEC power the Rx and winch servo(6V).

is this possible?

Yes, build a receiver bypass like you have pictured for the steering servo, plug the winch into the receiver.

-----------------------------------------------------------------------


*is this correct?

Yes.

*does the signal wire require the ground that goes from the "G" to the RX? or does it only need to go from the BEC to the Servo? the adapter above goes to all 3 it appears.

As mentioned, Spektrums require it, Futaba and others may or may not.

* on the adapter above the signal appears to come from one of the plugs that are glued together but the ground comes from the other plug. but theres a jumper between the two. so does the origon of the ground from either glued end not matter? because of the jumper?

So long as all three points are connected electrically, the origin of the ground doesn't matter.

*since i will have "two" becs running, is there any chance of any kind of back power feed threw the signal wire/ground back to the rx threw the adapter/diagram above? does having the ground wire from the "G" to the RX affect this answer?

If built exactly as your diagram shows, then...... no, and no.

Yes, this question does come up a lot, and there are quite a few who are adamant about not running the ground to all three points. But if your radio 'may or may not need it', I just don't understand why someone would leave it out, knowing full well that there's a chance they'll wind up tearing apart all their work just to add that in later. Perhaps it's just laziness on my part, but every bypass I've ever built has had that jumper in there, every one's worked fine, and I've never had to tear one apart to add anything in. {shrug}
IMO, the OP's diagram is spot-on, just needs to make it happen. Check all connections before powering up, make sure there's no red connection at the receiver, and you should be set. Report back and let us know how ya make out.
 
I use these cut off the prong for the red going to the rx and make a pig tale for the signal and ground to the rx. This set up seem a little smaller to me.
 
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