Have recently lost an airplane because battery plug pulled loose. My ESCD was rated BEC. I understand this means battery pack serves both the motor as well as receiver . Is it possible to get a ESC without BEC so you use a separate battery for the receiver and does that battery power the servos so if you lose the battery pack for the motor you stll retain control with the pack that powers the reciever and servos?

Simple answer: yes. Opto isolated ESCs do not have BEC. Better answer, if you don't want to use the BEC, simply pull the red wire out of the rcx plug and insulate it, then use a separate battery pack.

Walt

Thanks for the info Walt. I will try that. You are referring to the red wire that is in the plug that plugs into the recvr through the throttle port? The throttle still works through the ESC?The servos would work through the reciever battery?

Ken Solomonj
[email protected]

Yes.
WT

The middle wire (red) is the power wire in the servo/receiver/ESC system. The yellow, white, or orange wire carries the control signals. The black (sometimes brown) wire is common.

When an ESC with BEC is connected to a receiver, power for the receiver is delivered through the red wire. Then the receiver further distributes power to the servos. When you disconnect the red wire, control signals still pass from the receiver to the ESC through the yellow, white, or orange wire. But then you must use a separate battery to provide power for the receiver and servos.

FYI, by using the middle wire as the power wire, no harm is done to any of the components if you mistakenly connect a servo plug backwards. The servo won't operate of course, but at least it won't be damaged. Earlier systems which had the power wire in one of the outboard positions could result in damaged components if you plugged in a servo backwards.

- Jeff

What kind of plane are you flying?  What kind of receiver pack are you planning?

Weight could be an issue.  You may be better served using a more secure battery connection than adding a receiver pack.

I was flying an ASpera from 3D hobbys. I think weight would be a problem but not a difficult one. Space would be more difficult but I could put a small 4.8 V battery in the rear of the cockpit and try and get the CG right. The main thing is to separate the batt power so during low voltage cut or main batt disconnect I have control through servos.


Ken