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Old 07-27-2011, 12:35 PM   #1
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Default Question about bec and separate receiver pack

Hello folks,
Why is my esc doesn't work when I remove the red wire from the receiver plug to the receiver?

I use a separate receiver battery pack to power my steering servo and receiver, so naturally I should disable the esc internal bec so the receiver pack and bec doesn't coincide with each other. I disable the bec from the esc by removing the red wire from the receiver plug. This leave the receiver plug with only the signal and the ground wire. In general the signal wire only needs the ground wire to work properly.
When I plug the receiver battery pack to the receiver the servo and receiver work properly in response to the transmitter, the lights on the esc respond properly to the transmitter, like when I pull the throttle trigger to advance the throttle, the lights on the esc ramp up accordingly. But the motor doesn't run. WHY?
On my helicopters, I just simply remove the red wire from the receiver plug when I wanted to run an external receiver pack and the esc and motor work the way it should.

Now when I plug back in the red wire on the esc receiver plug and use it with the external receiver battery pack the esc and motor work properly again. However, there is another issue that I notice. The esc will respond to the transmitter command and engage the motor from the power of the receiver pack, without the main battery pack plug in.

Tekin rs pro
Lrp x12 17.5
1s lipo

Thanks
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Old 07-27-2011, 01:50 PM   #2
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Sounds like the ESC does not like having its internal bec bypassed

Ring Tekin and ask them if it should be possible

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Old 07-27-2011, 02:25 PM   #3
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This would be a good place to ask this, we run 1 cell in oval & the tekin reps answer these issues often.

http://www.hobbytalk.com/bbs1/showthread.php?t=277167

I would attempt to answer but I run another esc, I have heard of this happening.
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Old 07-27-2011, 02:54 PM   #4
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OK take a break and breath.

I use Tekins in both 1/12 and WGT with receiver packs.

It sounds like you are not getting the ESC connected to the 1S. You need to check those wires.

I leave the red wire in the plug since it doesn't have any bad effect on the BEC. The ESC will light up when you plug in the receiver pack and the LEDs will ramp up and down but the motor won't work unless the main battery is connected.

Now the ESC switch can be on or off, it doesn't matter except if you want the ESC to sense the Main Battery's voltage and use the cut-off and then you need to leave the ESC switch on.

I've using this set up for two years without any issues. My guess is that the main battery isn't connected to the ESC.
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Old 07-27-2011, 11:35 PM   #5
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can anybody answer this? i have a spektrum s6100 , at the moment i am running it at 6.0v but am thinking of running it at 7.2v. the sever is a high voltage servo so the 7.2v will make it faster. i am running it in a hyper 9e with a mamba monster and a 2650kv motor. will running the servo at 7.2v with a bec drain my batteries alot faster or will it be unoticable?
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Old 07-28-2011, 12:11 AM   #6
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You wont even notice it

Servos peak at 4 amps or so

Your motor is capable of peaking over 150 amps

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Old 07-28-2011, 08:43 AM   #7
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Quote:
I leave the red wire in the plug since it doesn't have any bad effect on the BEC. The ESC will light up when you plug in the receiver pack and the LEDs will ramp up and down but the motor won't work unless the main battery is connected.
Well, when I connect the receiver battery to the receiver, the servo and esc work and the lights ramp up and down in response to transmitter inputs, and also the esc will activate the motor from the receiver battery power even if the main battery is not connected. Yes the the motor does indeed run from the power of the receiver battery through the esc receiver plug, not fast but it does run. This is a bad effect in a sense that the motor does draw a bit of current from the receiver battery pack.

When I remove the red wire from the esc receiver plug, and power the receiver with a separate receiver pack and the esc with a separate 1s main battery, the lights on the esc will ramp up and down in response to transmitter inputs but the motor does not run. That weird!
I guess that's just how this esc is designed. All aircraft esc I have used in the past will work properly even when I remove the red wire from their receiver plug. A proper practice when you want to run a separate receiver battery pack for extra reliability purposes, or unload the extra work from the esc.
It look like this esc is screwed if its bec ever decided to go out.
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Old 07-28-2011, 09:46 AM   #8
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Well you are not supposed to run the motor off the receiver pack.

Whatever!!!!

What can I say, mine works and that's all I care about.
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