I understand that the circuit posted on the site www.555-timer-circuits.com of the servo controller (under servo tester) works as follows: u turn the potmeter and the servo turns by a degree proportional to degree the potmeter is turned.
Now i wantted to create an adjustment for this circuit.
first of all i want to create this with a joystick instead of a potmeter. But the joystick should also have to be pulled in reverse, meaning that i basicly want to control the amount the servo turns with a joystick, in both ways.
However, i am not sure if the initial circuit makes sure the servo turns back to the original state, but in what i have in mind it should do this.
With circuit you posted and the pot fully CW the servo will be full in one direction and with the pot fully CCW the servo will be full in the opposite direction. When the pot is centered the servo would be centered. The Pulse Width runs from about 1.0 to 2.0 mS with a 1.5 mS center which should be servo center. So if you remove and replace the 100K pot with a 100K joystick it should do exactly what you want and expect. The PRT of the circuit is about 20 Hz.
^ True and the greater the deflection angle in many cases the greater the cost. I was thinking of units like these. Those only offer 55 degree (+/- 27.5) deflection. Stock is a 5K pot with 10K available so the circuit would need modified.