Pololu RC Servo Multiplexer Sel channel

I’ve been working with the Pololu RC Servo Multiplexer and have a general question about the “Select” pins. I’m running into a problem isolating voltages. I have servos and a battery system that I would like the Pololu RC Servo Multiplexer to draw from and route. The R/X system has a different battery and voltage that I would like to use as the “select” for the Pololu RC Servo Multiplexer but not power it.

So far the only way I can get the Pololu RC Servo Multiplexer to respond is to connect it to the R/X with a standard 3wire servo wire. However this also causes the Pololu RC Servo Multiplexer to draw power from the R/X. My original thought is I could just use the signal wire from a standard 3wire servo wire from the R/X to the Pololu RC Servo Multiplexer, thus eliminating the power draw.

Is there a way I can Isolate the R/X signal from the power so that the signal from the R/X can operate the “SEL” on the Pololu RC Servo Multiplexer?

Thanks

Question answered… Thanks John at Pololu

As I don’t have a background in electronics I wasn’t sure what can and cannot be safely done when it comes to wiring. The solution was to use the signal and ground wire of the 3wire servo wire. This removes the power from being drawn from the R/X system and forces the MASTER and SLAVE systems to be powered only by those inputs.

It worked… Thanks again.