Hi,

Has anyone information on where to get specifications for the signals used to control servos?  I would like to build so0me electronic switches to pulg into my receivers.  I would like the details of signal levels, timing and frequencies on the "white wire."  Does anyone have a reference, link, or company I can contact?

Thanks, Bob

        _____                                          ___       3 to 5V
        |        |                                        |    |
____|        |____________________|    |____  0V

        |<-->|
        1 to 2 ms

        |<----------------------------->|
         20ms

The pulse width determines the servo position. 1.5ms is the center. This is the standard servo signal. However, there are some special digital servos made for heli tail that uses a faster signal.

Hi,

Thanks RotorZone for your help.  That explains why I've had problems filtering the signal and picking out the DC level.  There just isn't much.  I shall have to use the 1.5 ms timing and a one-shot timer.

Regards, Bob

Hi Bob,

If you are looking to make a switch that could be controlled from your TX, then there are a handful of circuits available in the net. Let me know if you need a circuit diagram.

-Ismail

Hi Izmile,

I'd very much like that   It's very kind of you.  I've had a go myself and after 9 resistors, 1 diode, 2 caps and 4 transistors, I've got a design.  There must be a simpler one out there...!

Regards, Bob.

Here one of the circuits that I pulled off the web. I built it and it worked great. The nicest thing about this circuit is that you can set the trip point of the switch by tuning the trim pot.