Hi,
I am working on a radio controlled project, but am having difficulty with one thing. I want to run a relay off a servo output, but as the output, (connections to motor) is in the form of a square wave, I cannot have this. The relay obviously switches on/off to the square wave, whereas I cannot have this happing.
Is there some form of circuit which I can build to rectifiy the square wave output to DC.
Or is there an alternative way of running a relay from a servo output?

Thanks for your help.

 

The square-wave fed to an RC servo is continuous. The width of the pulses is changed to move the servo or speed controller. So if you rectify the pulses then the relay will vibrate with a fairly low average voltage to a higher but still pretty low average voltage.

You need a circuit that will decode the width of the pulses.

 

Thanks for info, but would you know the name of the circuit I would need to look for?
THANKS

 

I couldn't find an on-off circuit for Radio control.
A pulse occurs about every 20ms. Its width is determined by the movement of the joystick. Minimum pulse width is 1ms and maximum pulse width is 2ms so you need a circuit to give a high when the pulse width is more than 1.5ms and give a low when it is less than 1.5ms.

 

I will look into these,
Thanks for the help!