Optima Receiver SPC + Independent BEC (2 different LiPos)

[Fasa]

Hi all, sorry about bother you with this that maybe is a basic question.

In the next Scenario (the image is from the internet for referential purpose only) :



If i plug the main battery, the SPC and the ESC (without BEC) are powered. If i do this without connect the receiver battery + BEC for the servos. Will the receiver have signal in the outputs? More precisely.. Will the ESC have signal for their normal initialization if the BEC is not powered?

In my real scenario, I want to connect an Optima9 to a single LiPo (6S) thru the SPC port. The servo bus will be powered thru a 7.4V BEC connected to an independent 2S LiPo. Instead of the Servos the signal will go to a FBL unit.

My concern is about the boot up process.
If I should connect the BEC first, my FBL unit will start without receiver signal (due to it is connected thru the SPC port which isn´t yet powered in this order).
If the ESC does not initialize without the BEC powered, I’m in a trouble also…

That´s the why of my question.
Thanks in advance.

Best regards.

PS: Sorry about my English.

[dpelletier]

If only the SPC port is receiving power I am pretty sure that there will be a signal the servo side but there will be no power to start for the servos or in your case the FBL.

You could test this easily enough...
1. Disengage the motor pinion for safety.
2. Turn on your transmitter
3. make certain throttle is set NOT to arm ESC
4. Plug in your flight pack, power SPC(receiver) and ESC
5. Move throttle to arm ESC.
If the ESC arms... then your question is answered signal gets through without power on the servo bus of the receiver.

I think that is really the point of the SPC port... allow signal to get through to the servos no matter what voltage (if any) is getting to them.

No matter how it works out, you should always power up the Trasmitter up first, then the receiver (ESC unarmed) then power to the servos (FBL unit)
this way you have control over what signal gets to the ESC.

[A.T.]

Originally Posted by Fasa

Hi all, sorry about bother you with this that maybe is a basic question.
In the next Scenario (the image is from the internet for referential purpose only) :
<snip>
If i plug the main battery, the SPC and the ESC (without BEC) are powered. If i do this without connect the receiver battery + BEC for the servos. Will the receiver have signal in the outputs? More precisely.. Will the ESC have signal for their normal initialization if the BEC is not powered?
In my real scenario, I want to connect an Optima9 to a single LiPo (6S) thru the SPC port. The servo bus will be powered thru a 7.4V BEC connected to an independent 2S LiPo. Instead of the Servos the signal will go to a FBL unit.
My concern is about the boot up process.
If I should connect the BEC first, my FBL unit will start without receiver signal (due to it is connected thru the SPC port which isn´t yet powered in this order).
If the ESC does not initialize without the BEC powered, I’m in a trouble also…
That´s the why of my question. Thanks in advance. Best regards.
PS: Sorry about my English.

As in post #2, must also emphasize:
. Transmitter On First - Off Last
This post might also assist:
. Optima Transceiver (RX) - EP Models Use SPC Port for RX Power Supply (BEC only is unreliable) & correct Battery Telemetry.

ex Hitec USA Support Forum Sticky:
Aurora 9, AFHSS 2.4Ghz Module, Transceivers_Receivers & Telemetry,
- FAQ, Setups & Tips

Alan T.
Alan's Hobby, Model & RC FAQ Web Links

[Fasa]

Thanks to both!

I would liked to reply with test already done, but i have to update my firmware before.

As soon as possible i will post the result but i don´t want to stop to say thank you.

Regards.

[Fasa]

Well, sorry about the delay, I have recived the HPP-22 last friday and yesterday i bought some connectors to do the test.

I can confirm now that when the power is applied to the Optima9 thru the SPC port, there will be no signal on the servo side of the receptor. (The ESC will not start)

Because of this i built a male-female power cable between the Battery and the ESC with the SPC cable connected in parallel.
Now i have 3 steps on the boot up process. First i plug this extention to the main batery that give power to the SPC that give power to the radio side of the Optima9,after this i plug the secondary lipo to the BEC that give power to the servo side of the receiver, this allow to start the FBL unit, and finally i plug the ESC to the other side of this extention and the system is fully functional.

Now i have the telemetry of the main Lipo with alarms set on the Aurora9 and a separated LiPo with independent BEC for the electronics and servos.

This extra connector adds weight and possible fail points, So.. if anyone like to try this make sure to use very good connectors and do the soldering correctly.

I hope it was usefull to somebody.

Regards and thanks again.

PS: Sorry about my English.