sodbuster 1

Here's the situation.
Installed a JR 791 retract servo not knowing it's meant to be run on 4.8V.
Installed a 5 cell (6V) NiMH RX pack as I want the maximum performance from my servo's.

Retract servo won't work on the 6V pack.

Can I regulate the voltage for one channel coming out of a Spektrum AR7000 RX?

Would something like this work if I run a jumper for the signal leg??

http://www.cermark.com/products/Stan...mp-limit.html#

BuschBarber

My Feedback: (2)

I use the JR 791 Retract servos in an H9 P47-150. It was interesting the when I used a JR 649 PCM 72Mhz Rx they worked fine on 6v. When I switched to a Spektrum AR9000 Rx, with 6v, they glitched at one end. Horizon told me that they were not compatible with 6v. I was using a 6v JR NiMh Rx pack. I installed a 5v MPI Voltage Regulator and they work fine, now. I even switched to 2cell LiPo Rx packs and everything works fine. You can buy Servo Extensions with Voltage Regulators in line, for each JR 791 servo, and then all of your other servos will run at 6v. I just decided to use the one Voltage Regulator because my P47 did not necessarily the faster speed and more torque that 6v provided. I also have flown the bird on 4.8v, without any Voltage Regulators, but I love LiPos, A123 cells, and Enyloop batteries.

Campgems

The question would be if the regulator would pass through the signal lead, also if the ground, black lead, is hard wired through. If this isn't the case, you would have to rig up some sort of wire around for signal. Most regulators are designed to be between the battery and receiver, or between the battery and distribution pannel.

Another way to handle it would be to use a seperate battery for the retract servo, and just feed ground and signal from the RX to the servo with a common ground to your new battery and plus from the new batter to the servo. Of course, you need a second switch.

If you dont't need the extra torque or speed from the servos that a 6V pack supplies, just go to a High Mah 4.8 battery.

I have some High Torque Futaba servos that are only listed at 4.8V. I checked with Bax and was told that I could use a voltage regulator set at 5.8V without problem on these servos. Kind of the best of both worlds, Higher voltage and Torque than a 4.8V pack but slightly less than a 6V pack.

Lots of ways to get from point A to point B. You just need to find the path that suits you best.

Don

redfox435cat

no it doesn't pass through the signal, the signal wire isn't present. you can take a 6in extension and unpin the signal wire from the female connector and put the lead in the regulators female connector and plug that into the receiver and hook the other end of the extension into the servo bypassing the regulator

Flying Geezer

My Feedback: (14)

You can buy small regulators from almost any heli supplier. They have the signal wire running straight thru. I have them on 2 helis and run the receiver, all other servos, and the gyro unregulated. The tail servo takes it's power thru the gyro. I use the regulator between the gyro and the tail servo because the tail servos, (all the best ones), will not take 6 volts.

Mine are regulated to 5.2 volts.

Look at [link]http://heliproz.com[/link]

sodbuster 1

any idea how many amps this servo can peak at?
think it's torque value is something like 260 oz.

victorzamora

Another thing you can do, which is sometimes recommended anyway, is to use a separate battery pack for your retract servo....and simply use a 4.8v battery for it. This way, if your retracts bind...it won't drain your main receiver pack.

jaka

Hi!
Never use the reciever battery pack as power supply for your retracts! You risk your airplane if one of the landing gears would stick in the wheel wells.
Use a small separate battery (4,8V , 400mAh NiMH cells or there about) for the retract servo.

BuschBarber

My Feedback: (2)

The Retracts in the H9 P47-150 have separate JR791 Retract servos in each Gear. Each Retract servo goes in to a separate channel on the Rx so the gear can be mixed and made to go up at different speeds.

sodbuster 1

Why that is wonderful. And that is relevant to this thread in what way please?
please see the question at the top.

BuschBarber

My Feedback: (2)

It is relevant because it would involve 2 battery packs for the Retracts or some other way to provide battery power to the Retract servos other than from the Rx.