There is a classic circuit for stopping a voltage increasing beyond a certain value in analogue circuitry And here it is, modelled using LTSpice. It is the same circuit as the classic simple precision rectifier (set to pass the negative half-sine), but with the non-inverting input of the op-amp connected to the voltage-to-clamp-to rather than …
This story continues at Precision rectifier/clamp works near 0V for single-supply circuits
Or just read more coverage at Electronics Weekly