HELP! I need help with servo/receiver power source

[Termite]

I'm setting up a Trex 600N. I have a Futaba radio, an R6208 Receiver, iKon FBL unit, Futaba BLS451 servos on cyclic and JR DS8900G on the tail. How do I know if I need a voltage reducer? I'm using a 2s Lipo for my power source.

[NAFEAR]

The cyclic servos I believe can only take about 4.8 volts.The BLS451 can handle probably 6 volts.If you are using a 2S battery you will have 7.4 volts available.So you will need a regulator..

[Termite]

Thanks! Any suggestions on regulators??

[meowguy]

The JR VR6015 is one of the best. See it here: http://www.jramericas.com/195447/JRPVR6015/

[Termite]

Is it true that if I run a LiFe receiver pack that I don't need a regulator?

[dchekas]

I ran the BLS451s for many years straight off a 2S LiPo without any issues.

[jiminator]

You could run the bls451's straight off a LiFe but the 8900g you will need to step down. I run a couple of 8900's at 5.2v from a regulated port on a Spek AR7110R receiver with no problems.

[meowguy]

Is it true that if I run a LiFe receiver pack that I don't need a regulator?

That depends on the voltage rating of the servos.

Older servos run only at 4.8v. Newer servos run from 4.8 to 6v (this is low voltage by modern standards) High voltage servos run from 6v to 8v and are usually powered with a 2S LiPo. Any servo rated as 4.8v to 6v will run fine on a 2S LiFe without a regulator. High voltage servos can also run on a LiFe, but they put out less power and speed at the lower 6v.

Check the manufacture's specs. beforehand.

[Termite]

LOL....This servo thing, starting again after a 5 yr break, is making me feel pretty stupid. I get the basic concept but I'd like to figure out a way to make everything work together without an "extra" component .

[meowguy]

Another consideration is current draw. If you are flying a flybarless heli, the servos work a lot harder and draw more current. An old school flight pack switch is not going to cut it. The voltage regulator I mention has it's own switch and carries a 15 amp load. You could power the VR with a 2s 5000ma Lipo so the servos would run at 6v with tons of power. As suggested you could still use the step down for the tail and/or throttle servo if nitro.

[Termite]

Ok, I just changed this heli to FBL. So if I use the 2S lipo (which I have already) and get the VR, I still need something else to step down the voltage for the tail and throttle or the VR does tht also? Sorry, I have not met with the guys at the club for the year yet.....started to do this on my own and it is not as clear cut as it use to be with all of the options. I don't even want to plug anything in because I'm afraid I'll fry something before I even start.

[meowguy]

The output voltage of the VR is 6 volts. That is still too hot for your 4.8 volt tail or throttle. One of these will do for each 4.8 volt servo you want to have. Futaba Futaba PS01RS 1 Amp Step Down Voltage Regulator FUTM0960. See this link. http://www3.towerhobbies.com/cgi-bin...P?I=LXBHZU&P=8

[Termite]

Thanks for your help! I really appreciate it.

[ticedoff8]

Buy a Scott Gray reactor V2.
It is 2S LiPo input with dual regulators built in.
http://www.scottgrayrc.com/reactorx.html
One regulator is adjustable and feeds the 3 cyclic at 6v, 6.8v or direct LiPo voltage and the other regulator feeds the FBL / throttle servo / tail rotor at a fixed 5.2v.
It includes a "fail on" on/off switch

The JR DS-8900G is a 4.8v servo that is designed with 5.2v as the maximum input.
The 4.8v servos were designed for 4 cell Nickel Cadmium (NiCad) batteries.
NiCad have a nominal voltage of 1.2v per cell (4 x 1.2 = 4.8) and fresh off the charger, they are up around 1.26v to 1.28v / cell (4 x 1.28 = 5.1v)

The BLS451 are rated at up to 6v (a 5 cell NiCad). At full charge, a 5 cell NiCad is around 6.4 max.

Going higher than the maximum designed voltage on any electronics is risky.
I would not run any 6v rated servo at 2S LiPo, but they are typically ok at 2S LiFe voltages.

Since Ive started using LiPo batteries, I have not tried a direct connection from teh battery to the RX / servos. I started using regulators.

You can buy the Reactor V2 used for around $30

I run the Reactor V2 on my 600N and the Reactor HVX on my 700N.

The MSH iKON is rated up to 9v.
And, it works good with the Futaba S.Bus
Make sure you upgrade the software to the latest before you start your setup.
Make sure you select the simple "Digital servo" and not the "High End". Set the pulse width and the refresh frequency to 1520uS / 200Hz for all 4 servos.

[Termite]

Ah crap! I just ordered a Western Robotics voltage regulator. But if I don't think I can make it work I'll send it back and go for the SG reg. Thanks for taking the time and giving the suggestions.

[Riff]

Just go with 2s LiFePo4 (A123) batteries and get servos that can handle it. Make your life easier and enjoy happy flying .