Chokes are used to cancel out jitters or spikes interfering with the source supply. These types of circuit fidelity components include ferrite filters on power source connections, also twisted pairs of cables insure that these undesired effects are affecting both lines. Then using combination of these filtering methods ensure a safe operating source against low voltage artifacts. Safety against high voltage crippling and invasive surges, use combinations of MOVs, fuses and especially spark gaps on your PCB.
