



Why am I not getting full rotation out of this servo mechanism?
I'm not an electronics engineer but we did control theory so I tried making this analog PID servo mechanism made using op amps. The issue is Im only able to get 180 degress of rotation about the centre from the sensor potentiometer. The rotation near the ends seems to be non existant even tho Im turning the setpoint potentiometer near its end (shown in the video). All potentiometers are 10k, op amps are TL072cp, power amplifier at the end is made of tip120 (npn) and tip127 (pnp). The images of schematic are in the comments below.