Raptor 50 + Lipo Setup

[Birds]

Hi.

I am thinking of changing from Sub C Nicad receiver pack to lipo pack for longer duration and lighter weight.

Found this BEC with 3S lipo as input and outputs at 5v at 3A continuous and 5A burst.

Can this BEC be use in a heli setup with all Digital Servos??

If not, please share your lipo setup


Thanks!!

[sookainian]

3AC 5AB should be fine for a 50 size with all digitial.

[Xue]

How many volts do you intend to run for your servos? 4.8V or 6V?

Gyro is fixed from 4.8V to a maximum 5.2 above that will sure blow up the gyro...

There are 3 ways to run a Lipo setup...

1) By using a 5V regulator means all electronics will be running at 5V

2) By using 2 regulators at the sametime one 5V to your gyro and one 6V to all other electronics

3) By getting the Arizona regulator which supply 2 different volts at the same time...the arizona regulator will supply fixed 5V to your gyro and 4.8V~6V depending on your preference to all other electronics...

[Birds]

Thanks

Thanks for prompt replies!

So what lipo setup is recommended for running at 5v?

I understand that the 9253/54 cannot handle more than 5.3v.

What Lipo capacity and configuration are you using (2s1p, 2s2p, 3s1p?)
Approx how many flights? I am targeting up to 5 flights without recharging.

[helirulz]

If you're using a BEC, a 3s1p would be reccommended.

However, if you're using a linear regulator such as Duralites or the Arizona, the best would be to get 2s2p(going higher in series is only a waste of voltage)

BEC's are more effecient however a rating of 3A constant might not be suficient, If you overdraw current, your BEC might just shut down and Oolala!
not forgetting BEC's produce RF noise which might get you into a glitch

I'd reccommend the Arizona

[AceViperX]

I thikn the correct name is actually a Switching regulator. BEC (Battery Eliminator Circuit) only applies to ESCs which provide power to the rest of the electrical circuit.

The reason why its a waste of battery using more than 2S on a linear regulators is due to the fact that any voltage that is beyond the 5.2-6v required by the linear regulator will be lost as heat.

On the other hand switching type regulators are more efficient even at higher input voltage because with the increase in input voltage there will be a drop of input current required. Power = voltage * ampere. Power provided at the output is equalto the power required at the input. So the higher voltage you provide the switching regulator, the lower the amp requirement.

If you're using a BEC, a 3s1p would be reccommended.

However, if you're using a linear regulator such as Duralites or the Arizona, the best would be to get 2s2p(going higher in series is only a waste of voltage)

BEC's are more effecient however a rating of 3A constant might not be suficient, If you overdraw current, your BEC might just shut down and Oolala!
not forgetting BEC's produce RF noise which might get you into a glitch

I'd reccommend the Arizona

[ethinger]

Ubec is good enough.
but you dont need the 3s1p though... 2s is fine.
the 1700 Etecs are not bad for Rx batteries.. it will last i'll promise you that.

[bell206]

Hi.

I am thinking of changing from Sub C Nicad receiver pack to lipo pack for longer duration and lighter weight.

Found this BEC with 3S lipo as input and outputs at 5v at 3A continuous and 5A burst.

Can this BEC be use in a heli setup with all Digital Servos??

If not, please share your lipo setup


Thanks!!

Hmmm, this BEC is a little suspicious. I don't see any heat sink attached. At 5V, 3A continuous, it's bound to generate enough heat even for a switching regulator to require a proper heat sink.

For your raptor and your own safety, I don't think it's worth taking the risk.

The Arizona regulator has a large heat sink attached which may also act as some kind of RF shield to minimize interference.

[AVAGLO]

Hmmm, this BEC is a little suspicious. I don't see any heat sink attached. At 5V, 3A continuous, it's bound to generate enough heat even for a switching regulator to require a proper heat sink.

For your raptor and your own safety, I don't think it's worth taking the risk.

The Arizona regulator has a large heat sink attached which may also act as some kind of RF shield to minimize interference.

from my knowledge ubec is a switching type regulator dosent produce much heat and more accurate where the analog type have big heat sink and not as accurate. is 3 a really enought for all servo any one done a current test???

[Brandon Chng]

3a is not enough.

[bell206]

from my knowledge ubec is a switching type regulator dosent produce much heat and more accurate where the analog type have big heat sink and not as accurate. is 3 a really enought for all servo any one done a current test???

The concept that a switching type regulator dosent produce much heat is not entirely correct. A switching regulator only produces less heat than a linear one.

Assuming an efficiency of 80% for the switching regulator, at 5V, 3A, it still need to dissipate >3 watts of heat!

[Zildjian]

I m using webra regulator c/w batt indicator and switch.Running with 2cell 2200mah lipo so far so good . I get it at Hobby Shack.

[Birds]

3A enuff?

Thanks for all the feedback!

From the Fromeco website, they conducted and measured the current drawn from an all Digital Servos setup. This setup is drawing around 2A with an occasional 4A spike.

3A continuous and 5A burst seems to be within specs.

But... the ultimate question, is anyone using this with good results?

Dun want to find out the hard (and expensive) way

[Fit]

2 wks ago i was in the same boat as you. Was very tempted by the price to try the UBEC that you mentioned above. But wasnt too sure if it works well and has enough filtration. The price and features are too good to be true and in our hobby it usually is. My main concern is mainly getting glitches from the cheap switching regulator. I am very paranoid about glitching!

Given a choice I would still go for a Linear reg. anytime. In the end i built myself my own Fromeco regulator. The regulator is the Sharp PQ7DV10 and is the same regulator used by Fromeco. Only 5 parts and costs about $15 to build. Had 3 flights and works wonderfully.
If you are confident and comfy with electronics and simple soldering you may want to go my route.

Thanks for all the feedback!

From the Fromeco website, they conducted and measured the current drawn from an all Digital Servos setup. This setup is drawing around 2A with an occasional 4A spike.

3A continuous and 5A burst seems to be within specs.

But... the ultimate question, is anyone using this with good results?

Dun want to find out the hard (and expensive) way

[Super-Hornet]

Eh... most Linear and switching allow to connect 2 or more together in parallel to increase the o/p current. (Preferable in the same model and brand).

U can go for double or more but make sure they can work together. (Oh... BTW, LM7805 / LM7806 can connect in parallel to increase the o/p current)

To check whether your BEC can supply 3A or 6A (if double), maybe the easiest way is to connect to a big motor and an Ampere meter and Voltmeter. Then tries to load down the motor and then check the volt and amp. The volt should remain at 5V/6V while the current shoot up.

EDIT: Wow! the Sharp PQ7DV10 can supply a huge 10A!! Yum. Fit.. where u get that chip?

SH