Receiver Battery pack size?

[RyanMcCrae]

Im going to power my receiver by a separate battery. Im unsure how large it needs to be and if lipo with a bec is the best way to go about it.
Since its not going to be powering anything other than the receiver I cant imagine it would have to be a big battery.

What size would you buy?
Would you get a lipo with bec or another type of battery?

Cheers Ryan

 

[BorisS]

Hi Ryan,

why are you planning on powering the RX separately ? Its just another LIPO to take care of and check that its not low etc.

Boris

 

[RyanMcCrae]

Im going to be running a emcotec remote controlled power kill switch, the receiver needs its on battery to make this happen. Alough I just had a thought. I could just pull power off the main battery pack before it hits the emcotec unit. Can you see any issue with that?

 

[Efliernz]

Ryan

I have no experience with the kill-switch system but if you need just an independent rx battery... a basic 2S lipo + UBEC will do. An rx on its own will barely draw 50-100mA. A 2S1200 - 2S1800mA lipo would have you sorted all day - with a <100g penalty.

Pete

 

[BorisS]

Hmm not really see a problem there. BEC to RX powered from the main battery, switch on the system from your Radio. I don't see any GND loops that wouldn't be there anyways. But i don't have any experience with remote power switches !

I was just thinking in my terms I always forgot stuff and every part that i can spare or don't have to take care off eases my setup time and chances that i actually get to fly once i reach my destination.

 

[BorisS]

which kind is it ?

this one ?

http://shop.rc-electronic.com/e-ven...ionId=&a=article&ProdNr=A11071&t=11&c=39&p=39

Boris

(edit) nah something more like this or ? http://www.hkm-models.com/images/Anleitung_SPS_EN.pdf

 

[RyanMcCrae]

I cant see the first link (session timed out) But its the safety power switch combined with the SPS-RCS, http://shop.rc-electronic.com/e-ven...&a=article&ProdNr=A72035&t=2263&c=2263&p=2263
Which just turns the safety power switch on and off via remote. I agree with what your saying BorisS Im the same, if I can get around having another battery I would much rather do that.

 

[RyanMcCrae]

Ryan

I have no experience with the kill-switch system but if you need just an independent rx battery... a basic 2S lipo + UBEC will do. An rx on its own will barely draw 50-100mA. A 2S1200 - 2S1800mA lipo would have you sorted all day - with a <100g penalty.

Pete

Would a 2s have enough voltage at 6.6, to drop to 6v ok? I thought becs needed a bit more voltage for the drop?

 

[BorisS]

Depends on the BEC. The first component that has to be powered is you RX powering the SPS-RCS than the power switch or ? Or does the power switch power backward to the SPS-RCS and than the Receiver which would be great !

 

[BorisS]

Actually what i am getting at is if your RX can work with 4.8 v for example like the futaba SB series than a CC pro bec could do the job:

Input 5v to 25.2vVoltage: (2S to 6S LiPo)


Default setting: 5.1 volts. User selectable in 1/10th volt incrementsbetween 4.8 and 9 volts.

 

[RyanMcCrae]

BorisS, does this answere your question about wiring?

http://www.rc-electronic.com/downloads/pdf/bedienungsanleitungen/Anleitung_SPS_RCS_Single_EN.pdf

 

[BorisS]

Think thats the way it could be done with a BEC.

View attachment 8241

Bec in this case could be a CC BEC

And thats the way it would be cool if they would have thought about it. Although they don't really indicate where the RX is powered from

View attachment 8242

Boris

 

[BorisS]

Most of the telemetry Voltage and Current sensors are able to power the main logging unit and the rest of the sensors, so why didn't they think of their power switch being able of powering the Switch remote and the RX, or maybe it does !

Boris

 

[RyanMcCrae]

Thanks alot for those diagrams. Ive found one from a NZ hobbyshop so I should have it in a few days to test which way works. Il have a Graupner telemetry unit, which i assume i would wire in after the switches. Is that what your meaning. Run the rx off a bec and then run the ys-x6 off of the tele unit? http://www.kopterworx.com/Hott/Air-Module-2-14S-HoTT

 

[BorisS]

First thing i would do is to hook the power switch and the power remote thingi together and hook it up to a lipo. Take a multimeter and measure if there is a voltage output that could power the RC : Here like in the diagram.

View attachment 8243

If there is not than the BEC solution would be the next attempt. In this case though it would be good to check continuity on the GND that goes into the Power Switch from the main Lipo and the GND the leave the Power Swicht to the Remote Thinigi just to go sure one if not creating a GND look, but I am pretty sure it won't be the case.
They could have shown more to this product more descriptions !

Boris

 

[BorisS]

Thanks alot for those diagrams. Ive found one from a NZ hobbyshop so I should have it in a few days to test which way works. Il have a Graupner telemetry unit, which i assume i would wire in after the switches. Is that what your meaning. Run the rx off a bec and then run the ys-x6 off of the tele unit? http://www.kopterworx.com/Hott/Air-Module-2-14S-HoTT

Seems like it also need input voltage:

Specification

Dimensions (LxWxH)	51 x 47 x 18	mm
Operating voltage	3,6 ... 8,4	V

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Which is really stupid. ( Sorry don't want to rag on it ) but its on the main lipo, it should have an internal voltage regulator and power itself. Smaller device like this one power themselves and the unit that come after it :

and than on it powers the main logging unit

 

[BorisS]

nah sorry for the false alert the graupner module does feed itself and docent need an external power supply. The info was misleading !

View attachment 8244View attachment 8245

 

[BorisS]

Ah okay and than thats also the setup wait now i know what you have to do ! Ill draw it up.

 

[BorisS]

Okay Graupner Current sensor powers RX RX power remote for Switch and Switch itself:

Nothing else need no BEC or RX Lipo.


View attachment 8246

But this only in the case if the Safety Switch doesnt power the Remote switch already and then the remote thing and the RX. If that the case than you see sparks if you hook it up like above. So the most important thing stays.

Do this first " First thing i would do is to hook the power switch and the power remote thingi together and hook it up to a lipo. Take a multimeter and measure if there is a voltage output that could power the RX"

Than it has to be hooked up in a different way. But once more I don't think you will need a LIPO or extra bec to power the RX either the graupner oder the safety switch components will take care of it !

Boris

 

[RyanMcCrae]

Good point, i always assumed it would have worked at full voltage, it seems odd, because it works on up to a 14s battery, so how can it measure all the voltages if its coming though a regulator first?