forward and reverse rc servo with a single throw switch?

Thread Starter


Joined Nov 29, 2011
hello all,
this is my first time here and i need a little help. i found my way here searching for info on reversing a rc servo with the single throw switch on my tx. i found a short video of what i want to do any help on what circuitry i need to make this work would be greatly appreciated.


Joined Feb 11, 2008
You can use a 555 timer IC, as an astable frequency generator with the correct duty cycle to give the waveform for RC servo position 1.

Then a switch can short out a resistor (or change over a resistor) in the timer and change the duty cycle, so the RC servo will then move to position 2.

If you use a couple of pots for the resistors that control duty cycle you can set each position with a pot, then use the switch to move from position 1 to position 2.


Joined Jul 17, 2007
Hmm - I think that there is just a bit more to it than that, Roman.

You mentioned "servo", but need to verify:
Is it a servo that rotates 360 degrees continuously?
Or is it a servo that you want to run all the way to the right, then back to center, then all the way to the left, then back to center?
Or is it a DC motor that you wish to run forwards & backwards?

What voltage(s) do you have to work with?