Power bus on 600esp

[Peteren]

Do I need the power bus module to fit the SK720 to my Trex600 ESP?

The AR6200 receiver I'm currently using seem's to drive all the servo's OK

Also I'm using the Spektrum DX8 and am assuming that this will work fine with the 720?

Cheers

[georgi UK]

=] some 700e pilots don't use the bus, some 500/550e pilots do, if you are really pushing the heli its probably recommended,, otherwise monitor the voltage shown in the logs,

DX8 is fine, the next firmware update will detect a 2048 bad boot, so force a 1024 bind until then.

georgi UK

[Peteren]

Thanks georgi, I have just ordered the bus with the 720 just in case.

I noticed in the 720 setup sticky that the bus was wired directly to the 2C lipo and then a regulator on the rudder servo

Can this be done as per the existing ESP setup

e.g. 2C lipo - BEC (5.8V) - bus/720 - all servos ?

[georgi UK]

=] you will need to decide, based upon the hardware you are running,

whether to run unregulated 2s to the bus cables, some pilots are flying 610's this way, the tail will need a step down.

or to run regulated using the bec also making sure the tail is protected and not exceeding its max voltage.

perhaps T6 pilots could chime in??!

georgi UK

[whittb]

I would highly recommend running a BEC on your setup regardless of what voltage you are running. The stock ds610,ds620 servos on the Trex 600 can handle 6 volts. I have heard people say they run them at 8.4 volts. If you ever have a battery malfunction, it could fry all your electrical equipment if you do not run a BEC.

My 550E has a Western Robotics pro 15amp BEC that runs the power bus. I run everything at 6 volts. The advantage to using the power bus is that it keeps all the high AMPS from your servos out of the SK720 unit. this is what can cause the brown outs to occur. The only power coming from the bus to your SK720 is the power from the tail servo connection. All other bus to SK720 connections are signal only. This is the way they recommend setting it up anyway.

If you want to run you cyclic servos unregulated then you should provide a smaller BEC to power the tail servo and the SK720. The power bus has two sides. A high voltage side and a low voltage side. This allows you to connect two different isolated power supplies.

I am in the process of building a 600 nitro and a SK720. The regulator I am using eliminates all the amps coming from the cyclic servos in to the SK720. For this reason, I decided not to use the power bus. I run my throttle and tail servo off a 5.5 volt 5.5 amp regulated power supply connected to the SK720. It can handle the lower amps. At lest it did on my smaller heli’s anyway…

Hope this helped

[Peteren]

Cheers guy’s, it sounds like I should leave the system as supplied by Align and just install the 720 & bus in place of my current receiver

[whittb]

That’s what I have been doing. It really does not save an money, you still need two satellite revivers, but is will simplify you wiring and setup.

[rceccleston]

Personally, I wouldn't run the stock linear Align regulator because it is only rated to 6 amps max, will run hot under the high loads the flybarless systems creates and so will become very inefficient.

While I have had many hundreds of successful flight with a CC BEC Pro connected to the power bus, from the 12s flight packs, I am moving away from this setup since an esc fire burnt out the BEC too.

I will be running a 2s Li-Fe 6.6v 30c pack directly to the cyclic servos with an in-line step-down on the tail.

This will greatly simplify the wiring and the reliability of the setup, since the servos are not reliant upon a BEC or regulator to drop-down the voltage from a receiver pack.